Mitral heart defects: main symptoms and syndromes
Aortic heart defects: main symptoms and syndromes
Acute and chronic heart failure. Vascular insufficiency
Heart Valvular Disease
Stable pathological changes in the structure of the heart that interfere with its normal function are called heart valvular disease. Congenital and acquired diseases of the heart valves are distinguished. The incidence of acquired heart diseases is much higher.
The structure of the heart
Valvular heart disease is any disease process involving one or more of the valves of the heart (the aortic and mitral valves on the left and the pulmonary and tricuspid valves on the right). Valve problems may be congenital (inborn) or acquired (due to another cause later in life). Treatment may be with medication but often (depending on the severity) involves valve repair or replacement (insertion of an artificial heart valve.
MITRAL INCOMPETENCE
Incompetence of the mitral (bicuspid) valve (mitral insufficiency) is incomplete closure of the atrioventricular orifice during left-ventricular systole. As a result, the blood is regurgitated from the ventricle back to the atrium. Mitral incompetence may be organic and functional.
Organic insufficiency arises as a result of rheumatic endocarditis. Connective tissue develops in the cusps of the mitral valve which then contracts to shorten the cusps and the tendons. The edges of the affected valve do not meet during systole and part of the blood is regurgitated through the slit into the left atrium from the ventricle during its contraction.
In functional (relative) incompetence the mitral valve is not altered but the orifice, which it has to close, is enlarged and the cusps fail to close it completely. Functional incomenetcei of the mitral valve may develop because of dilatation of the left ventricle (in myocarditis, myocardial dystrophy, or cardiosclerosis) and weakening of the circular muscle fibers that form the ring round the atrioventricular orifice. Affection of papillary muscles mav also cause functional mitral incompetence. Functional insufficiency thus depends on dysfunction of the muscles responsible for the closure of the valve.
Haemodynamics. If the mitral valve fails to close completely during systole of the left ventricle, part of the blood is regurgitated into the left atrium. Blood filling of the atrium thus increases (because of the blood from the pulmonary veins which is added to the normal blood volume. Pressure in the left atrium increases, the atrium is dilated and becomed hypertrophied.
The amount of blood that is delivered into the left ventricle frpm the overfilled left atrium during diastole exceeds normal and the atrium is thus overfilled and distended. The left ventricle has to perform excess work and becomes hypertrophied. Intensified work of the left ventricle compensates for the mitral incompetence during a long time. When thw contractile power of the left ventricular myocardium weakens, distolic pressure in it increases and this in turn increases pressure in the left atrium.
Increased pressure in the left atrium increases pressure in the pulmonary veins and this in turn causes reflex contraction of the arterioles in the lesser circulation (Kitaev’s reflex) due to stimulation of baroreceptors. Spasm in the arterioles increases significantly pressure in the pulmonary artery to intensify the load on the right ventricle which has to contact with a greater force in order to eject blood into the pulmonary trunk. The right ventricle can therefore also be hypertrophied during long-standing pronounced mitral incompetence.
Causes and mechanisms of mitral regurgitation
MR=mitral regurgitation. PM=papillary muscle. RF=rheumatic fever.
* Mechanism involves normal leaflet movement.
† Mechanism involves excessive valve movement.
‡ Restricted valve movement, IIIa in diastole, IIIb in systole.
Schematic anatomical mitral-valve presentation
(A) Atrial view of a healthy mitral valve. Posterior leaflet has a shorter length but occupies a longer circumference than the anterior leaflet. Mitral annulus around the leaflet is part of the aortic-mitral fibrosa superiorly, is asymmetric, and short in its anteroposterior dimension. Leaflet segmentation starts with A1—P1 close to the anterolateral commissure, with A2—P2 centrally, and A3—P3 close to the posteromedial commissure. The normally apposing leaflets make up the mitral smile. (B) Example of a flail posterior leaflet affecting the P2 segment with ruptured chordae. Note the bulge and excess tissue of the flail segment and the annular enlargement mostly along the posterior part of its circumference. (C) Initial step of surgical valve repair. Resection of the flail segment can be triangular (as shown) or quadrangular and leaves the healthy P1 and P3 segments available for reattachment and repair. (D) Posterior leaflet has been restored by approximation of the remaining segment after resection of the flail segment and the mitral annular dimensions have been restored by an annuloplasty ring. In this example an incomplete ring has been used with its extremities sutured to the trigonal regions of the aortic-mitral fibrosa. The mitral smile and competence have been restored.
Clinical picture. Most patients with mild or moderate mitral incompetence have no complaints for a long time and look very much like healthy subjects. As congestion in the lesser circulation develops, dyspnoea, palpitation of the heart, cyanosis, and other symptoms appear.
Appearance of the patient with mitral incompetence
Palpation of the heart area reveals displacement of the apex beat to the left, sometimes inferiorly. The beat becomes diffuse, intensified, and resistant, which indicates hypertrophy of the left ventricle. Percussion reveals displacement of the heart’s borders to the left and superiorly because of the enlarged left atrium and left ventricle. The configuration of the heart becomes mitral with an indistinct heart waist. The border of the heart shifts to the right in hypertrophy of the right ventricle. Auscultation I the heart reveals decreased first sound at the heart apex because the valves never close completely in this disease. Systolic murmur can be heard at the same point, which is the main sign of mitral incompetence. It arises during systole when the stream of blood passes a narrow slit leading from the left ventricle to the left atrium. The systolic murmur is synchronous with the first sound. When the blood pressure rises in the lesser circulation, an accent of the second sound can be heard over the pulmonary trunk.
Аудіо: систолічний шум.mpg Аудіо: systolic murmur.mpg
Аудіо: II heart sound accentuation.mpg
Auscultation findings are confirmed and verified by phonocardiography. The pulse and arterial pressure do not change in compensated mitral incompetence.
X-ray studies show a specific enlargement of the left atrium and the left ventricle detectable by eniargement (to the left, superiorly and posteriorly) of the heart silhouette. When blood, pressure increases in the lesser circulation, the pulmoafry arcn dilates.
Signs of hypertrophy of the left atrium and the left ventricle can also be found on the ECG: it becomes the left type and the P waves become higher.
Echocardiography reveals distention of the left heart chambers (atrium and ventricle), movement of the mitral valve cusps in the opposite direction, their thickening and the absence of full closure during systole.
Echocardiographic appearance of the two main anatomical types of mitral regurgitation from apical views centred on the mitral valve
(A) An example of a flail posterior leaflet with the tip of the leaflet floating in the left atrium. Note the otherwise grossly normal anterior leaflet. (B) An example of functional mitral regurgitation. Strut chordae (long arrows) to the anterior and posterior leaflets exert an abnormal traction on the body of the leaflets, which displaces (arrowheads) the leaflets towards the ventricular apex, creating an area of tenting above the mitral annulus and an incomplete coaptation. LA=left atrium. LV=left ventricle.
Doppler echocardiography is the main method for assessment of patients with mitral regurgitation. Transthoracic or transoesophageal echocardiography provides functional anatomical information that is crucial for assessment of reparability by defining cause, mechanism, presence of calcification, and localisation of lesions. Transoesophageal echocardiography provides better imaging quality than transthoracic echocardiography but its ability to detect details such as ruptured chordae rarely changes management. Transoesophageal echocardiography essentially provides incremental clinically meaningful information (such as reparability) when transthoracic echocardiography is of poor quality or when complex, calcified, or endocarditic lesions are suspected. Thus, transoesophageal echocardiography is rarely used on an outpatient basis and is mostly used intraoperatively for lesion verification and to monitor surgical results. Real-time three-dimensional echocardiography has at present insufficient image resolution but pilot data suggest that it allows quantitative assessment of structures that are not easily measurable by two-dimensional echocardiography, such as mitral annulus. Although emerging technologies such as transoesophageal echocardiography three-dimensional imaging have great potential, they need to be rigorously tested.
Doppler echocardiography provides crucial information about mitral regurgitation severity (table). Comprehensive integration of colour-flow imaging and pulsed and continuous wave doppler echocardiography is necessary because jet-based assessment has major limitations (figure). Quantitative assessment of regurgitation is feasible by three methods—quantitative doppler echocardiography based on mitral and aortic stroke volumes, quantitative two-dimensional echocardiography based on left-ventricular volumes, and flow-convergence analysis measuring flow with colour-flow imaging proximal to the regurgitant orifice (proximal isovelocity surface area method; figure ). These methods allow measurement of ERO area and RVol and have important prognostic value. Severe mitral regurgitation is diagnosed with an ERO area of at least 40 mm2 and RVol of at least 60 mL per beat; and moderate regurgitation with ERO area 20—39 mm2 and RVol 30—59 mL per beat. Outcome data suggest that a smaller volume mitral regurgitation and smaller ERO area (≥30 mL and ≥20 mm2, respectively) are associated with severe outcome in patients with ischaemic disease; therefore, thresholds for severe disease are cause-dependent. Consistency in all measures of mitral regurgitation severity is essential to appropriately grade disease severity (table ). Haemodynamic assessment is completed with doppler measurement of cardiac index and pulmonary pressure.
Gradation of mitral regurgitation by doppler echocardiography
Modified from Zoghbi and colleagues.5 ERO=effective regurgitant orifice area. LA=left atrium. LV=left ventricle. MR=mitral regurgitation. RF=regurgitant fraction. RVol=regurgitant volume.
Use of colour-flow imaging for assessment of mitral regurgitation
(A) Jet imaging in left atrium. The jet is eccentric and is displayed with mosaic colours, whereas the normal flow is of uniform colour. It fills only part of the left atrium and might underestimate the regurgitation. The observation of a large flow convergence should lead to suspicion of severe regurgitation. (B) Measurement of the flow convergence with colour-flow imaging. The baseline of the colour scale has been brought down to decrease the aliasing velocity to 53 cm/s (velocity at the blue-yellow border), which allows the flow convergence (yellow) to be seen. The radius (r) of the flow convergence is used in the formula for calculation of the instantaneous regurgitant flow (258 mL/s). Flow=6·28×Valiasing×r2=6·28×53×0·882=258 mL/s. Division of this value by the jet velocity allows calculation of the effective regurgitant orifice of mitral regurgitation. LA=left atrium. LV=left ventricle.
Doppler echocardiography also measures left-ventricular and left-atrial consequences of mitral regurgitation. End-diastolic left-ventricular diameter and volume indicate volume overload whereas end-systolic dimension shows volume overload and ventricular function. Patients with left-ventricular ejection fraction less than 60% or end-systolic diameter of at least 40—45 mm are regarded as having overt left-ventricular dysfunction. Left-atrial diameter indicates volume overload but also conveys important prognostic information. Left-atrial volume was recommended as the preferred measure of atrial overload, (at least 40 mL/m2 for severe dilatation) and predicts the occurrence of atrial fibrillation.
X-ray in mitral incompetence. Mitral heart configuration
Ultrasound picture of mitral incompetence. Enlarged left ventricle and atrium
Mitral incompetence may remain compensated for a long time. But a long-standing pronounced mitral incompetence and decreased myocardial contractility of the left atrium and the left ventricle cause venous congestion in the lesser circulation. Contractility of the right ventricle can later be affected with subsequent development of congestion in the greater circulation.
STENOSIS OF THE LEFT ATRIOVENTRICULAR ORlfICE
The left atrioventricular orifice usually narrows in a long-standing rheumatic endocarditis (stenosis ostii venosi sinistri). In very rare cases mitral stenosis may be congenital or secondary to septic endocarditis. The atrioventricular orifice narrows due to adhesion of the mitral cusps, their consolidation and thickening, and also shortening and thickening of the tendons. The valve thus becomes a diaphragm or a funnel with a slit in the middle. Cicatricial and inflammatory narrowing of the valvular ring is less important in genesis of mitral stenosis. The valve may be calcified in longstanding stenosis.
Rheumatic fever is the leading cause of mitral stenosis (MS) (Table). Other less common etiologies of obstruction to left atrial outflow include congenital mitral valve stenosis, cor triatriatum, mitral annular calcification with extension onto the leaflets, systemic lupus erythematosus, rheumatoid arthritis, left atrial myxoma, and infective endocarditis with large vegetations. Pure or predominant MS occurs in approximately 40% of all patients with rheumatic heart disease and a history of rheumatic fever. In other patients with rheumatic heart disease, lesser degrees of MS may accompany mitral regurgitation (MR) and aortic valve disease. With reductions in the incidence of acute rheumatic fever, particularly in temperate climates and developed countries, the incidence of MS has declined considerably over the past few decades. However, it remains a major problem in developing nations, especially in tropical and semitropical climates.
In rheumatic MS, the valve leaflets are diffusely thickened by fibrous tissue and/or calcific deposits. The mitral commissures fuse, the chordae tendineae fuse and shorten, the valvular cusps become rigid, and these changes, in turn, lead to narrowing at the apex of the funnel-shaped (“fish-mouth”) valve. Although the initial insult to the mitral valve is rheumatic, the later changes may be a nonspecific process resulting from trauma to the valve caused by altered flow patterns due to the initial deformity. Calcification of the stenotic mitral valve immobilizes the leaflets and narrows the orifice further. Thrombus formation and arterial embolization may arise from the calcific valve itself, but in patients with atrial fibrillation (AF), thrombi arise more frequently from the dilated left atrium (LA), particularly the left atrial appendage.
If stenosis is significant and the orifice is narrowed from the normal 4-6 cm2 to 1.5 cm2 and less, haemodynamics becomes affected considerably. During diastole, blood fails to pass from the left atrium to the left ventricle and the remaining blood is added to the blood delivered from the pulmonary veins. The left atrium thus becomes overfilled with blood, the pressure in the atrium increases. Excess pressure is first compensated for by intensified contraction of the atrium and its hypertrophy, but the force of the left atrial muscle is insufficient to compensate permanently for the pronounced narrowing of the mitral orifice and its contractile force soon weakens; the atrium becomes dilated, and the pressure inside it rises. This in turn increases pressure in the pulmonary veins, produces a reflex spasm in the arterioles of the lesser circulation and increases pressure in the pulmonary artery. All this requires intensified work of the right ventricle, which later also becomes hypertrophied. The left ventricle in mitral stenosis receives smaller volumes of blood and is therefore less active; its size slightly decreases.
Pathophysiology
Iormal adults, the area of the mitral valve orifice is 4–6 cm2. In the presence of significant obstruction, i.e., when the orifice area is reduced to < ~2 cm2, blood can flow from the LA to the left ventricle (LV) only if propelled by an abnormally elevated left atrioventricular pressure gradient, the hemodynamic hallmark of MS. When the mitral valve opening is reduced to <1 cm2, often referred to as “severe” MS, a LA pressure of ~25 mmHg is required to maintain a normal cardiac output (CO). The elevated pulmonary venous and pulmonary arterial (PA) wedge pressures reduce pulmonary compliance, contributing to exertional dyspnea. The first bouts of dyspnea are usually precipitated by clinical events that increase the rate of blood flow across the mitral orifice, resulting in further elevation of the LA pressure (see below).
To assess the severity of obstruction hemodynamically, both the transvalvular pressure gradient and the flow rate must be measured. The latter depends not only on the CO but on the heart rate as well. An increase in heart rate shortens diastole proportionately more than systole and diminishes the time available for flow across the mitral valve. Therefore, at any given level of CO, tachycardia including that associated with AF augments the transvalvular pressure gradient and elevates further the LA pressure. Similar considerations apply to the pathophysiology of tricuspid stenosis.
The LV diastolic pressure and ejection fraction (EF) are normal in isolated MS. In MS and sinus rhythm, the elevated LA and PA wedge pressures exhibit a prominent atrial contraction (a wave) and a gradual pressure decline after mitral valve opening (y descent). In severe MS and whenever pulmonary vascular resistance is significantly increased, the pulmonary arterial pressure (PAP) is elevated at rest and rises further during exercise, often causing secondary elevations of right ventricular (RV) end-diastolic pressure and volume.
Cardiac Output
In patients with moderate MS (mitral valve orifice 1.0 cm2–1.5 cm2), the CO is normal or almost so at rest but rises subnormally during exertion. In patients with severe MS (valve area <1.0 cm2), particularly those in whom pulmonary vascular resistance is markedly elevated, the CO is subnormal at rest and may fail to rise or may even decline during activity.
The clinical and hemodynamic features of MS are influenced importantly by the level of the PAP. Pulmonary hypertension results from: (1) passive backward transmission of the elevated LA pressure; (2) pulmonary arteriolar constriction, which presumably is triggered by LA and pulmonary venous hypertension (reactive pulmonary hypertension); (3) interstitial edema in the walls of the small pulmonary vessels; and (4) organic obliterative changes in the pulmonary vascular bed. Severe pulmonary hypertension results in RV enlargement, secondary tricuspid regurgitation (TR) and pulmonic regurgitation (PR), as well as right-sided heart failure.
Clinical picture. When congestive changes occur in the lesser circulation, the patient develops dyspnoea and palpitation on physical exertion; he complains of pain in the heart, cough, and haemoptysis. Inspection reveals acrocyanosis and cyanotic blush on the face. If the disease develops in childhood, the patient’s physical growth often slows down and infantilism may develop (“mitral nanism”). Visual examination of the heart region often reveals a cardiac beat consequent upon dilatation and hypertrophy of the right ventricle. The apex beat is not intensified; its palpation can reveal diastolic cat’s purr (presystolic thrill). The broadening of cardiac dullness to the right and superiorly due to hypertrophy of the left atrium and right ventricle can be determined by percussion. The heart becomes “mitral” in configuration.
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Mitral face
In auscultation of the heart the first sound at the apex becomes loud and snapping because the left ventricle receives little blood and its contraction is fast. An adventitious sound due to the opening of the mitral valve can be heard at the apex beat. It follows the second sound of the heart. The loud first sound, second sound, and the sound of mitral valve opening give a specific murmur which is characteristic of mitral stenosis. The second sound becomes accentuated over the pulmonary trunk when pressure in the lesser circulation increases. Diastolic murmur is characteristic of mitral stenosis because the passage from the left atrium to the ventricle during diastole is narrowed. This murmur can be heard to follow the mitral valve opening sound (protodiastolic murmur) because the velocity of the blood flow in early diastole is higher due to the pressure difference in the al and the ventricle. The murmur disappears when the pressures equalize. If stenosis is not pronounced, the murmur can be heard only at the diastole, immediately before systole proper (presystolic murmur); it arises during acceleration of the blood flow at the end of ventricular diastole because of the early atrial systole. Diastolic murmur can be heard in mitral stenosis during the entire diastole. It increases before systole and joints the first snapping sound.
The pulse in mitral stenosis may be different on the left and right arms. In considerable hypertrophy of the left atrium, the left subclavian artery is compressed and the pulse on the left arm becomes smaller (pulsus differens). If the left ventricle is not filled completely and the stroke volumej decreased, the pulse becomes small (pulsus parvus). Mitral stenosis is often complicated by atrial fibrillation, and the pulse becomes arrhythmic. Arterial pressure usually remains normal; the systolic pressure sometimes slightly decreases and diastolic pressure increases.
X-ray patterns of a heart show the specific enlargement of the left atrium, which leads to disappearance of the heart waist and “mitral” configuration appears. Enlargement of the left atrium is determined in the first oblique position by the degree of displacement of the oesophagus which becomes especially vivid with barium sulphate suspension. If pressure in the lesser circulation increases, X-rays show swelling of the pulmonary arch and hypertrophy of the right ventricle. X-ray pictures sometimes show calcification of the mitral valve. Pneumosclerosis develops during long-standing hypertension of the lesser circulation; it may also be revealed during X-ray examination.
X-ray in mitral stenosis. Mitral heart configuration.
The ECG of the heart with mitral stenosis shows hypertrophy of the left atrium and the right ventricle: the amplitude and duration of the P5 wave increase, especially in the first and second standard leads; the electrical axis of the heart deviates to the right, a high R wave appears in the righr chest leads and a pronounced S wave in the left chest leads.
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ECG in mitral stenosis
A phonocardiogram taken at the apex shows the high amplitude of the first sound; the second sound is followed by the mitral valve opening sound and diastolic murmur; the amplitude of the second sound over the pulmonary artery increases compared with that over the aorta. If PCG and ECG are taken synchronously, attention should be paid to the length of the interval Q-I sound (from the beginning of the Q wave on the ECG to the first sound on the PCG) and the second sound—Q interval.
Echocardiograms in mitral stenosis are characterized by the following:
1. The A wave, describing the maximum opening of the atrial systole either decreases or disappears altogether
2.The speed of diastolic closure of the anterior mitral cusps decreases to decrease the E-F slope.
3.Movements of the cusps change. The cusps of a normal mitral valve move in the opposite direction to set apart during diastole: the anterior cusp moves toward the anterior wall while the posterior cusp to the posterior wall. In stenosis, these movements become unidirectional because the more massive anterior wall pulls the posterior one by adhesion. The movement of the valve is represented on the echocardiogram in the form of a square wave. Enlargement of the left atrium and changes in the cusps (fibrosis, calcinosis) can also be detected by echocardiography.
Mitral stenosis soon becomes attended by congestion in the lesser circulation which requires greater work of the right ventricle. Decreased contractility of the right ventricle and venous congestion in the greater circulation develop therefore in mitral stenosis earlier and more often than in mitral incompetence.
Dilatation of the right ventricle and weakening of its myocardium are sometimes attended by relative tricuspid insufficiency. Moreover, long-standimg venous congestion in the lesser circulation in mitral stenosis causes, with time, sclerosis of the valves and growth of connective tissue in the lungs. Another obstracle to the blood flow is thus created in the lesser circulation and this adds to the difficulties in the work of the right ventricle.
Transthoracic two-dimensional echocardiography (TTE) with color flow Doppler imaging provides critical information, including an estimate of the transvalvular peak and mean gradients and of mitral orifice size, the presence and severity of accompanying MR, the extent of restriction of valve leaflets and their thickness, the degree of distortion of the subvalvular apparatus, and the anatomic suitability for percutaneous mitral balloon valvotomy (PMBV; see below). In addition, TTE provides an assessment of the size of the cardiac chambers, an estimation of LV function, an estimation of the pulmonary artery pressure (PAP), and an indication of the presence and severity of associated valvular lesions. Transesophageal echocardiography (TEE) provides superior images and should be employed when TTE is inadequate for guiding therapy. TEE is especially indicated to exclude the presence of left atrial thrombi prior to PMBV.
AORTIC INCOMPETENCE
Aortic incompetence (aortic insufficiency) is the failure of the aortic valve to close completely during ventricular diastole; blood thus leaks back into the left ventricle. Aortic incompetence is usually secondary to rheumatic endocarditis, and less frequently bacterial (septic) endocarditis, syphilitic affection of the aorta, or atherosclerosis. Inflammatory and sclerotic changes occurring in the base of the cusps during rheumatic endocarditis make them shrink and shorten. Atherosclerosis and syphilis can affect only the aorta (to distend it), while the valve cusps are only shortened. The cicatricial changes may extend onto the cusps to disfigure them. Parts of the valve disintegrate in ulcerous endocarditis associated with sepsis and the cusps are affected with their subsequent cicatrization and shortening.
Haemodynamics. During diastole, blood is delivered into the left ventricle not only from the left atrium but also from the aorta due to regurgitation, which overfills and distends the left ventricle during diastole. During systole the left ventricle has to contract with a greater force in order to expell the larger blood volume into the aorta. Intensified work of the left ventricle causes its hypertrophy, while the increased systolic volume in the aorta causes its dilatation
Aortic incompetence is characterized by a marked variation in blood pressure in the aorta during systole and diastole. An inc reased volume of blood in the aorta during systole increases systolic pressure and since part of blood is returned during diastole into the.ventricle, diastolic pressure quickly drops.
Clinical picture. Subjective condition of patients with aortic sncompetence may remain good for a long time because the defect is compensated for by harder work of the powerful left ventricle. Pain in the heart (anginal in character) may sometimes be felt; it is due to relative coronary insufficiency because of pronounced hypertrophy of the myocardium and inadequate filling of the coronary arteries under low diastolic pressure in the aorta. The patient may sometimes complain of giddiness which is the result of deranged blood supply to the brain (which is also due diastolic pressure).
If contractility of the left-ventricular myocardium is impaired, congestion in the lesser circulation develops and the patient complaints of dyspnoea, tachycardia, weakness, etc. The skin of the patient is pallid due to insufficient filling of the arterial system during diastole. Marked variations in the pressure in the arterial system during systole and diastole count for the appearance of some signs, such as pulsation of the perphieral arteries, the carotids (carotid shudder), subclavian, brachial, temporal and other arteries; rhythmical movements of the head synchronous with the pulse (Musset’s sign), rhythmical change in the colour of the nail bed under a slight pressure on the nail end, the so-called capillary pulse (Quincke’s pulse), rhythmical reddening of the skin after rubbing, etc.
Appearance of the patient with aortic incompetence
The apex beat is almost always enlarged and shifted to the left and inferiorly. Sometimes, along with the elevation of the apex beat, a slight depression in the neighbouring intercostal spaces can be observed The apex beat is palpable in the sixth and sometimes seventh intercostal space laterally of the midclavicular line. The apex beat is diffuse, intense, rising like a dome. This indicates significant enlargement of the left ventracle. The border of cardiac dullness can be found (by percussion) to shift to the left; the heart becomes “aortic” (with pronounced waist of the herat.
Auscultation reveals decreased first sound at the apex, since during left-ventricular systole the period when the valves are closed is absent. The second sound on the aorta is also weak, and if the valve is damaged significantly, it can be inaudible. The second sound can be quite loud in atherosclerotic affection of the aorta. Diastolic murmur heard oer the aorta and at the Botkin-Erb listening point is characteristic. This is a low blowing protodiastolic murmur which weakens by the end of diastole sa the blood pressure in the aorta drops and the blood-flow rate decreases. The described changes in the sounds and murmurs are clearly visible on phonocardiogram. Murmurs of functional aetiology can also be heard in aortic incompetence at the heart apex. If the left ventricle is markedly dilated, relative mitral incompetence develops and systolic murmur can be heard at the apex. Diastolic murmur (presystolic or Austin-Flint murmur) can sometimes be heard. It arises due to an intence regurgitation of the blood that moves aside the mitral valve cusp to account for functional mitral stenosis. Doubled sound (Traube souble sound) nd doubled Vinogradov-Durozierz murmur can sometimes be heard over the femoral artery in this disease.
The pulse is fast, full, and high, which is due to high pulse pressure and increased volume of blood deliverred into the aorta during systole. Arterial pressure constantly varies^ the systolic pressure rises and diastolic falls, and the pulse pressure is therefore high.
X-ray studies show an enlarged left ventricle with a distinct waist of the heart and dilatation of the aorta; pulsation of the aorta is intense.
The ECG also reveals various signs of hypertrophy of the left ventricle: the electrical axis is deviated to the left, the S waves in the right chest leads are deep and the amplitude of the R wave is higher in the left chest leads; these signs often combine with signs of overstrain in the left ventricle and relative coronary insufficiency (changes in the terminal part of the ventricular complex, displacement of the S-T interval, and the negative T wave).
Echocardiograms taken from patients with aortic failure show flutter of the anterior mitral cusp during diastole caused by the thrust of the blood regurgitated from the aorta into the ventricle.
ECG in aortic incompetence
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Ultrasound in aortic incompetence: uncomplete closure of aortic valve, enlargement of the left ventricle
Ulrtasound examimation in aortic incompetence:
Echo-Doppler imaging of aortic regurgitation (video)
Example of a Jet of Aortic Regurgitation, as Shown by Color-Flow Imaging.
The three components of the regurgitant flow (flow convergence above the orifice, vena contracta through the orifice, and the jet below the orifice) are shown. The width of the vena contracta (as indicated by crosses) can be measured as a surrogate for the regurgitant orifice.
X-ray in aortic incompetence: aortic heart configuration
Aortic incompetence can for a long time be compensated for by intensified work of the hypertrophied left ventricle. When its contractile force decreases, congestion in the lesser circulation develops. Acute weakness of the left ventricle sometimes develops and is manifested by an attack of cardiac asthma. Dilatation of the weakened left ventricle can cause relative mitral incompetence. This increases venous congestion in the lesser circulation associated with decompensated aortic incompetence and adds to the load on the right ventricle. This is mitralization of aortic incompetence, which may become the cause of venous congestion in the greater circulation.
AORTIC STENOSIS
The narroving of the aortic orifice (aortic stenosis) interferes with expulsion of blood into the aorta during contraction of the left ventricle. Aortic stenosis is usually caused by rheumatic endocarditis; less frequently it develops due to bacterial endocarditis, atherosclerosis, or it may be congenital. Stenosis results from adhered aortic valve cusps or develops due to cicatricial narrowing of the aortic orifice.
Haemodynamics. During systole, the left ventricle is not emptied completely because part of blood fails to pass the narrowed orifice into the aorta. A new normal portion of blood delivered during diastole from the left atrium is mixed with the residual volume and the ventricle becomes overfilled. The pressure inside it thus rises. This disorder is compensated for by an intensified activity of the left ventricle to cause its hyperthrophy.
Clinical picture. Aortic stenosis can remain compensated for years and would not cause any unpleasant sublective sensations (even during intense physical exertion). If obstruction of the aortic orifice is considerable, infufficient blood ejection into the arterial system upsets normal blood supply to the hypertrophied myocardium and the patient feels pain in the heart (angina pectoris-type pain). Disordered blood supply to the brain is manifested by giddiness, headache, and tendency to fainting. These symptoms like pain in the heart would more likely occur during physical and emotional stress.
The skin of the patient is pallid due to insufficient blood supply to the arterial system. The apex beat is displaced to the left, less frequently ineriorly; it is diffuse, high, and resistant. Systolic thrill (cat’s purr) can be palpated in the region of the heart. Percussion reveals displacement of the left heart border; the heart is “aortic” due to hypertrophy of the left ventricle. Auscultation of the heart at its apex reveals diminished first sound due to overfilling of the left ventricle and prolongation of systole. The second sound is diminished over the aorta. If the aortic cusps adhere and are immobile, the second sound can be inaudible. Rough systolic murmur over the aorta is characteristic. This murmur is generated by the blood flow through the narrowed orifice. It is conducted by the blood onto the carotids and can sometimes be heard in the interscapular space. The pulse is small, slow, and rare, since the blood slowly passes into the aorta and its volume is decreased. Systolic arterial pressure is usually diminished, while diastolic remains normal or increases. The pulse pressure is therefore decreased.
X-ray examination shows hypertrophied left ventricle, “aortic” configuration of the heart, and dilatation of the ascending aorta (poststenotic); the cusps of the aortic valve are often calcified.
The ECG usually shows signs of hypertrophy of the left ventricle and sometimes of coronary insufficiency.
ECG in aortic stenosis
The phonocardiogram shows the specific changes in the heart sounds: diminished amplitudes of the first sound at the heart apex and of the second sound over the aorta. Systolic murmur over the aorta is typical; its oscillations are recorded in the form of -specific diamond-shaped figures.
Sphygmograms of the carotids reveal slowed ascent and descent of the pulse wave (slow pulse), small amplitude of the pulse waves, and specific serrated pattern of their peaks (sphygmograms in the form of a cock’s comb) showing oscillations associated with conduction of systolic murmur onto the neck vessels.
Echocardiograms show decreased opening of the aortic valve during systole. Echoes from the cusps become more intense and signs of hypertrophy of the left ventricle appear.
The key findings are LV hypertrophy and, in patients with valvular calcification (i.e., most adult patients with symptomatic AS), multiple, bright, thick, echoes from the valve.
Still frame two-dimensional echocardiographic image from the parasternal long axis view of a patient with aortic stenosis. The aortic valve is calcified with restricted opening during systole. Ao, aorta; RV, right ventricle; LA, left atrium; LV, left ventricle.
Standard evaluation of aortic stenosis (AS) severity is based on measurement of left ventricular outflow tract (LVOT) diameter (D) in a parasternal long-axis view for calculation of a circular cross-sectional area (CSA), outflow tract velocity (V) from an apical approach using pulsed Doppler, and the maximum aortic jet (AS-Jet, Vmax) from the continuous-wave Doppler recording. Either velocity-time integrals (VTIs) or maximum velocities can be used in the continuity equation for aortic valve area (AVA).
X-ray in aortic stenosis. Aortic heart configuration
Ultrasound examination in aortic stenosis. Narrowing of aortic aperture, enlargement of the left ventricle
Aortic stenosis remains compensated for a long time. Circulatory insufficiency develops in diminished contractility of the left ventricle and it is manifested as in aortic incompetence.
Treatment. Conservative treatment means management of heart failure. Operative treatment – implantation of artificial prostesis in incompetence or comissuritomy in stenosis.
The natural history of untreated organic and functional mitral regurgitation emphasises the importance of treatment of patients with severe regurgitation. Because the effects of various treatments on survival have not been tested in randomised clinical trials, the value of any approach is estimated on the basis of outcome studies.
Management strategy for patients with chronic severe mitral regurgitation. Mitral valve (MV) repair may be performed in asymptomatic patients with normal left ventricular (LV) function if performed by an experienced surgical team and if the likelihood of successful MV repair is >90%. AF, atrial fibrillation; Echo, echocardiography; EF, ejection fraction; ESD, end-systolic dimension; eval, evaluation; HT, hypertension; MVR, mitral valve replacement. (From Bonow et al.).
Medical treatment aims to prevent progression of organic disease. Prevention of endocarditis is directed at forestalling catastrophic infectious complications and sudden mitral regurgitation progression associated with endocarditis. Diuretics often reduce or eliminate symptoms of disease but such improvement should not unduly reassure physicians. Patients who had transiently severe symptoms and improved with treatment continue to be at high risk and should be promptly assessed for surgery.
Treatment of organic mitral regurgitation with vasodilators has been advocated on the basis of experimental studies showing reductions in acute RVol and even ERO area with blood pressure reduction. Acutely ill patients with mitral regurgitation benefit from vasodilator treatment. However, despite some encouraging data, translation to chronic treatment of organic disease is unresolved because reported series were small, rarely randomised, and contradictory in conclusions. Activation of the tissue (not systemic) renin-angiotensin myocardial system was shown in organic mitral regurgitation. Consistent pilot studies suggest potential of drugs blocking tissue renin-angiotensin system to stabilise organic disease severity and consequences. The effect of such treatments on clinical outcome remains to be shown. β blockade in organic mitral regurgitation has only been tested in animal models and remains conjectural. Conversely, in functional disease, medical treatment has been better studied than in organic disease. Maximum medical treatment of patients with heart failure and left-ventricular dysfunction reduces functional mitral regurgitation. Specifically β blockade—with carvedilol or long-acting metoprolol—and inhibition of angiotensin-converting enzyme reduce functional mitral regurgitation severity. These therapies are recommended for treatment of left-ventricular dysfunction. Thus, non-urgent surgical indications should be reviewed after maximum medical treatment has taken effect.
Interventional treatment is not yet approved for clinical use and remains investigational. Percutaneous revascularisation of patients with ischaemic regurgitation is possible but patients are often left with residual regurgitation that affects prognosis so that more effective treatment is necessary. Resynchronisation treatment in left-ventricular dysfunction with delayed conduction might improve functional mitral regurgitation. Two specific interventional approaches to treatment are discussed here.
Valvular edge-to-edge attachment mimics the surgical procedure proposed by Alfieri and colleagues, creating a tissue bridge between anterior and posterior leaflets. Percutaneously, this technique uses a clip or sutures deployed through trans-septal catheterisation. Experimental studies have shown success and reliable clip or suture placement through the trans-septal approach . Early trials also suggest safety and feasibility with close echocardiographic guidance in centres with much experience of interventional valvular procedures. Data for how well this intervention works are preliminary but encouraging, suggesting that more than 80% of patients can be discharged from hospital with a clip, and mild or little mitral regurgitation. A randomised trial comparing percutaneous clip and surgery is in progress. The edge-to-edge technique has important limitations. First, the application of this technique is restricted to localised prolapse of the central segment of the anterior and posterior leaflets. Second, annular dilatation is not addressed by the procedure and might cause residual regurgitation.
Percutaneous devices used for treatment of mitral regurgitation
(A) Percutaneous clip introduced by venous and trans-septal approach into the left atrium and through the mitral orifice. The clip then grabs both leaflets, resuspending them with prolapse. (B) Percutaneous coronary sinus cinching device introduced through the jugular vein into the coronary sinus. The distal stent (smallest) then the proximal stent are deployed. With time the bridge shrinks and cinches the annulus.
Annuloplasty aimed at reduction of annular dilatation is under investigation mostly with coronary sinus cinching. Technically, stabilisation of material with sufficient constraining force to obtain more than 20% diameter reduction is a challenge. Most devices are composed of anchoring devices placed in the distal and proximal coronary sinus and an intermediate tensioning or supporting element. Experimentally, reduction of mitral regurgitation is achievable, but clinical results are preliminary. Feasibility through a jugular approach and safety seem to be acceptable. Potential limitations are those of annuloplasty (incomplete valve tenting correction) and those of coronary sinus approach that might reduce only part of the annular circumference with an effectiveness limited by the 1—2 cm sinus-annular distance. Because of safety concerns related to proximity of the coronary sinus and circumflex artery with potential artery compression, non-coronary sinus approaches to annuloplasty and percutaneous ventricular remodelling-constraint devices are being investigated.
On the basis of the success of balloon valvuloplasty for mitral stenosis, percutaneous treatment of mitral regurgitation is expected to be successful but this success will necessitate complex development that needs strong cardiologist—engineer collaboration and rigorous assessment.
Surgical treatment of mitral regurgitation is the only approach with defined clinical success, providing sustained relief of symptoms or heart failure. However, no randomised trial has been done to prove mortality or cardiac event reduction. The standard surgical approach is a median sternotomy, but sometimes only partial sternotomy or minimally invasive surgery through thoracoscopic approach can be used.
Valve repair includes an array of valvular, subvalvular, and annular procedures aimed at restoration of leaflet coaptation (ie, valvular normal function) and elimination of mitral regurgitation. These surgical techniques are more successful with redundant than with retracted or calcified leaflets. For valve prolapse, typical repair is resection (triangular or quadrangular) of the prolapsed posterior leaflet segment whereas the anterior leaflet is rarely resected. Subvalvular support can be obtained by chordal transfer or artificial chords rather than chordal shortening. Annuloplasty is routinely used with annular bands or flexible or rigid rings. Many additional technical procedures might be used at the surgeon’s discretion to restore coaptation and valve competence. Conversely, in functional mitral regurgitation, valve repair is rather uniform with restrictive annuloplasty substantially reducing the anteroposterior annular diameter. New rings aimed at annular reshaping, specific to each cause of functional regurgitation (ischaemic disease or cardiomyopathy) are now available but their incremental value (compared with traditional rings) is not defined. Valve repair is done in about half of patients who undergo surgery for mitral regurgitation in the USA and Europe. In centres with surgeons proficient in valve repair, more than 80—90% repair rates are achieved. A failed repair is caused rarely by systolic anterior motion of the mitral valve due to excessively redundant tissue or by stenosis, but more often by insufficient correction of a prolapse, recurrence of ruptured chords, and excessive tissue retraction or resection. Overall, reoperation after 10 years is necessary in 5% of patients with repaired posterior leaflet prolapse and 10% of those with anterior leaflet interventions. 20—30% of patients with repaired functional mitral regurgitation are estimated to have recurrent regurgitation. Reoperation rate is not greater after valve repair than after replacement and because of the morbidity and mortality advantages, valve repair is the preferred method of surgical correction of mitral regurgitation.
Valve replacement involves insertion of a biological or mechanical prosthesis. Bioprosthetic valve replacement is associated with low embolic risk but shorter durability, whereas mechanical valve replacement is associated with high risk of embolism and haemorrhagic complications (due to intensive warfarin treatment) but has potential for long-lasting durability. Results of randomised trials showed that within 10 years of surgery these risks are balanced. Older age determines the probability that bioprosthetic durability will be longer than life expectancy, and is the main bioprosthesis insertion indication (usually >65 years of age). Ability to achieve high-quality anticoagulation and patient’s desire also affect the choice of prosthesis. Irrespective of the prosthesis selected, conservation of subvalvular apparatus is essential for preservation of ventricular function. The risk of prosthetic complications makes surgical indications more restrictive when valve replacement is likely.
Mitral Valvotomy
Unless there is a contraindication, mitral valvotomy is indicated in symptomatic [New York Heart Association (NYHA) Functional Class II–IV] patients with isolated MS whose effective orifice (valve area) is < ~1.0 cm2/m2 body surface area, or <1.5 cm2 iormal-sized adults. Mitral valvotomy can be carried out by two techniques: PMBV and surgical valvotomy. In PMBV a catheter is directed into the LA after transseptal puncture, and a single balloon is directed across the valve and inflated in the valvular orifice. Ideal patients have relatively pliable leaflets with little or no commissural calcium. In addition, the subvalvular structures should not be significantly scarred or thickened and there should be no left atrial thombus. The short- and long-term results of this procedure in appropriate patients are similar to those of surgical valvotomy, but with less morbidity and a lower periprocedural mortality rate. Event-free survival in younger (<45 years) patients with pliable valves is excellent, with rates as high as 80–90% over 3–7 years. Therefore, PMBV has become the procedure of choice for such patients when it can be performed by a skilled operator in a high-volume center.
Outcomes after surgery for functional disease remain suboptimum. Operative mortality is still high despite definite surgical improvements. Long-term mortality and heart failure rates are high, although not unexpected in patients with coronary disease, previous myocardial infarction, reduced ventricular function, and vascular comorbidity. These suboptimum outcomes explain uncertainties in surgical indications. The value of mitral repair compared with replacement is also debated because mitral regurgitation often recurs after repair as a consequence of continued ventricular remodelling, which results in recurrent valve tenting. Determinants of postoperative outcome are myocardial viability, preserved mitral competence, and absence of sustained or advanced ventricular remodelling. Postoperative outcome of functional mitral regurgitation due to cardiomyopathy is mediocre and whether it is improved compared with outcome under medical management is doubtful. However, with low operative mortality, postoperative heart failure and symptomatic improvements are possible.
Heart Failure
Heart failure (HF), often called congestive heart failure (CHF) or congestive cardiac failure (CCF), occurs when the heart is unable to provide sufficient pump action to distribute blood flow to meet the needs of the body
The clinical syndrome of heart failure is the final pathway for myriad diseases that affect the heart.
Statistics. Heart failure is a common, costly, disabling, and potentially deadly condition.[4] In developed countries, around 2% of adults suffer from heart failure, but in those over the age of 65, this increases to 6–10%.Despite advances in management of heart failure, the condition remains a major public-health issue, with high prevalence, poor clinical outcomes, and large health-care costs. Risk factors are well known and, thus, preventive strategies should have a positive effect on disease burden.
Heart failure is a clinical syndrome and, thus, definitions are imprecise. Most include references to typical symptoms and objective evidence of abnormal ventricular function. Estimates of heart failure prevalence and incidence vary greatly because of non-uniformity in the definition, absence of a gold-standard measure for the disorder, and paucity of adequate and true epidemiological surveys. Furthermore, such data are confined largely to developed countries, although heart failure seems to be growing in developing nations.
Prevalence of heart failure rises steeply with increasing decades of life, particularly from age 50 years; the condition is rare in individuals younger than this age
Definition. The traditional view that heart failure is a constellation of signs and symptoms caused by inadequate performance of the heart focuses on only one aspect of the pathophysiology involved in the syndrome. Currently, a complex blend of structural, functional, and biologic alterations are evoked to account for the progressive nature of heart failure and to explain the efficacy or failure of therapies used in clinical trials. For example, the rationale for the use of beta-blockers in a patient with a poorly contracting heart is based on a conceptual framework broader than that which suggests the treatment of congestion with diuretics or digoxin. The rationale for using beta-blockers is predicated on an understanding of the role of the sympathetic nervous system in promoting the release of renin and other vasoactive substances that trigger vasoconstriction, tachycardia, and changes in myocytes that lead to disadvantageous ventricular dilatation. Heart failure has been described variously as: (1) an oedematous disorder, whereby abnormalities in renal haemodynamics and excretory capacity lead to salt and water retention; (2) a haemodynamic disorder, characterised by peripheral vasoconstriction and reduced cardiac output; (3) a neurohormonal disorder, predominated by activation of the renin-angiotensin-aldosterone system (RAAS) and adrenergic nervous system; (4) an inflammatory syndrome, associated with increased local and circulating proinflammatory cytokines; and (5) a myocardial disease, initiated by injury to the heart followed by pathological ventricular remodelling. In fact, these descriptions of heart failure pathophysiology are not mutually exclusive and all factor in the onset and progression of the clinical syndrome of heart failure. Moreover, development of heart failure generally proceeds in stages, from risk factors to end-stage or refractory disease.
Causes include either causal factors underlying heart failure or diseases that might affect prognosis or treatment. Common causes of heart failure include myocardial infarction and other forms of ischemic heart disease, hypertension, valvular heart disease, and cardiomyopathy. The term heart failure is sometimes incorrectly used for other cardiac-related illnesses, such as myocardial infarction (heart attack) or cardiac arrest, which can cause heart failure but are not equivalent to heart failure.
Systemic hypertension is the most frequent and well described comorbidity, relevant to both systolic heart failure and heart failure with preserved ejection fraction. Compared with data of epidemiological studies such as Framingham, findings of intervention studies in heart failure have underestimated the contribution of hypertension, perhaps because this diagnosis is usually embedded within ischaemic and other causes.
Coronary artery disease can lead to heart failure through various mechanisms. Extensive myocardial necrosis can result in pump failure. Infarction of small areas can cause regional contractile dysfunction and adverse remodelling with myocyte hypertrophy, apoptosis, and deposition of extracellular matrix. Furthermore, transient reversible ischaemia can arise with episodic dysfunction, even in the presence of typical resting left-ventricular function.
Diabetes mellitus is an important and sometimes overlooked comorbidity in patients with heart failure. People with diabetes are at strikingly higher risk of heart failure than are those without the disease, and they have higher mortality. The existence of a specific diabetic cardiomyopathy, independent of concomitant hypertension and large-vessel coronary artery disease, has been much debated. In support of this possibility, asymptomatic diastolic dysfunction is a frequent finding on echocardiographic investigation of individuals with diabetes. Furthermore, altered autonomic and endothelial function, advanced glycation end-product deposition, and disordered energy metabolism are shared traits of both diabetes and heart failure.
Both ventricular and atrial arrhythmias are typical associated disorders and can be implicated as causes of heart failure. Many factors contribute to the high rate of arrhythmias in chronic heart failure, including ischaemic heart disease, electrophysiological abnormalities, myocardial hypertrophy, and activation of several key neurohormonal systems. Moreover, patients might be taking proarrhythmic drugs. Furthermore, many heart failure agents cause electrolyte abnormalities that could exacerbate the underlying risk.
Other important comorbidities include respiratory disorders such as chronic airflow obstruction and sleep apnoea, cognitive dysfunction, depression, anaemia, chronic kidney disease, and arthritis. All comorbid disorders add considerable complexity to diagnosis and management.
Pathogenesis. Heart failure is usually associated with a structural abnormality of the heart. The initial injury might be sudden and obvious (eg, myocardial infarction) or insidious (eg, longstanding hypertension). In some instances, such as idiopathic dilated cardiomyopathy, it is unknown. Once the injury happens, a series of initially compensatory but subsequently maladaptive mechanisms ensue.
Compensatory mechanisms that are activated in heart failure include: increased ventricular preload, or the Frank-Starling mechanism, by ventricular dilatation and volume expansion; peripheral vasoconstriction, which initially maintains perfusion to vital organs; myocardial hypertrophy to preserve wall stress as the heart dilates; renal sodium and water retention to enhance ventricular preload; and initiation of the adrenergic nervous system, which raises heart rate and contractile function. These processes are controlled mainly by activation of various neurohormonal vasoconstrictor systems, including RAAS, the adrenergic nervous system, and non-osmotic release of arginine-vasopressin. These and other mechanisms contribute to the symptoms, signs, and poor natural history of heart failure. In particular, an increase in wall stress along with neurohormonal activation facilitates pathological ventricular remodelling; this process has been closely linked to heart failure disease progression. Management of chronic heart failure targets these mechanisms and, in some instances, results in reverse remodelling of the failing heart.
Increased levels of circulating neurohormones are only part of the response seen after an initial insult to the myocardium. Left ventricular remodeling is the process by which mechanical, neurohormonal, and possibly genetic factors alter ventricular size, shape, and function. Remodeling occurs in several clinical conditions, including myocardial infarction, cardiomyopathy, hypertension, and valvular heart disease; its hallmarks include hypertrophy, loss of myocytes, and increased interstitial fibrosis.
At the time of an acute myocardial infarction — in this case, an apical infarction — there is no clinically significant change in overall ventricular geometry (Panel A). Within hours to days, the area of myocardium affected by the infarction begins to expand and become thinner. Within days to months, global remodeling can occur, resulting in overall ventricular dilatation, decreased systolic function, mitral-valve dysfunction, and the formation of an aneurysm. The classic ventricular remodeling that occurs with hypertensive heart disease (middle of Panel B) results in a normal-sized left ventricular cavity with thickened ventricular walls (concentric left ventricular hypertrophy) and preserved systolic function. There may be some thickening of the mitral-valve apparatus. In contrast, the classic remodeling that occurs with dilated cardiomyopathy (right side of Panel B) results in a globular shape of the heart, a thinning of the left ventricular walls, an overall decrease in systolic function, and distortion of the mitral-valve apparatus
Classification.
There are many different ways to categorize heart failure, including:
· the side of the heart involved (left heart failure versus right heart failure). Right heart failure compromises pulmonary flow to the lungs. Left heart failure compromises aortic flow to the body and brain. Mixed presentations are common; left heart failure often leads to right heart failure in the longer term.
· whether the abnormality is due to insufficient contraction (systolic dysfunction), or due to insufficient relaxation of the heart (diastolic dysfunction), or to both.
· whether the problem is primarily increased venous back pressure (preload), or failure to supply adequate arterial perfusion (afterload).
· whether the abnormality is due to low cardiac output with high systemic vascular resistance or high cardiac output with low vascular resistance (low-output heart failure vs. high-output heart failure).
· the degree of functional impairment conferred by the abnormality (as reflected in the New York Heart Association Functional Classification)
· the degree of coexisting illness: i.e. heart failure/systemic hypertension, heart failure/pulmonary hypertension, heart failure/diabetes, heart failure/renal failure, etc.
Functional classification generally relies on the New York Heart Association functional classification. The classes (I-IV) are:
· Class I: no limitation is experienced in any activities; there are no symptoms from ordinary activities.
· Class II: slight, mild limitation of activity; the patient is comfortable at rest or with mild exertion.
· Class III: marked limitation of any activity; the patient is comfortable only at rest.
· Class IV: any physical activity brings on discomfort and symptoms occur at rest.
This score documents severity of symptoms, and can be used to assess response to treatment. While its use is widespread, the NYHA score is not very reproducible and doesn’t reliably predict the walking distance or exercise tolerance on formal testing.
In its 2001 guidelines the American College of Cardiology/American Heart Association working group introduced four stages of heart failure:
· Stage A: Patients at high risk for developing HF in the future but no functional or structural heart disorder.
· Stage B: a structural heart disorder but no symptoms at any stage.
· Stage C: previous or current symptoms of heart failure in the context of an underlying structural heart problem, but managed with medical treatment.
· Stage D: advanced disease requiring hospital-based support, a heart transplant or palliative care.
The ACC staging system is useful in that Stage A encompasses “pre-heart failure” — a stage where intervention with treatment can presumably prevent progression to overt symptoms. ACC Stage A does not have a corresponding NYHA class. ACC Stage B would correspond to NYHA Class I. ACC Stage C corresponds to NYHA Class II and III, while ACC Stage D overlaps with NYHA Class IV.
Diastolic Heart Failure
It is estimated that 20 to 50 percent of patients with heart failure have preserved systolic function or a normal left ventricular ejection fraction. Although such hearts contract normally, relaxation (diastole) is abnormal. Cardiac output, especially during exercise, is limited by the abnormal filling characteristics of the ventricles. For a given ventricular volume, ventricular pressures are elevated, leading to pulmonary congestion, dyspnea, and edema identical to those seen in patients with a dilated, poorly contracting heart. Characteristics of patients with systolic heart failure and those with diastolic heart failure are compared in Table 2. Patients with diastolic heart failure are typically elderly, often female, and usually obese and frequently have hypertension and diabetes. Mortality among these patients may be as high as that among patients with systolic heart failure, and the rates of hospitalization in the two groups are equal.36 The diagnosis of diastolic heart failure is usually made by a clinician who recognizes the typical signs and symptoms of heart failure and who is not deterred by the finding of normal systolic function (i.e., a normal ejection fraction) on echocardiography. Echocardiography may be useful in the detection of diastolic filling abnormalities.
Heart failure can cause a number of symptoms including shortness of breath, leg swelling, and exercise intolerance.
Signs
Left-sided failure
Common respiratory signs are tachypnea (increased rate of breathing) and increased work of breathing (non-specific signs of respiratory distress). Rales or crackles, heard initially in the lung bases, and when severe, throughout the lung fields suggest the development of pulmonary edema (fluid in the alveoli). Cyanosis which suggests severe hypoxemia, is a late sign of extremely severe pulmonary edema.
Additional signs indicating left ventricular failure include a laterally displaced apex beat (which occurs if the heart is enlarged) and a gallop rhythm (additional heart sounds) may be heard as a marker of increased blood flow, or increased intra-cardiac pressure. Heart murmurs may indicate the presence of valvular heart disease, either as a cause (e.g. aortic stenosis) or as a result (e.g. mitral regurgitation) of the heart failure.
Right-sided failure
Physical examination may reveal pitting peripheral edema, ascites, and hepatomegaly. Jugular venous pressure is frequently assessed as a marker of fluid status, which can be accentuated by eliciting hepatojugular reflux. If the right ventricular pressure is increased, a parasternal heave may be present, signifying the compensatory increase in contraction strength.
Biventricular failure
Dullness of the lung fields to finger percussion and reduced breath sounds at the bases of the lung may suggest the development of a pleural effusion(fluid collection in between the lung and the chest wall). Though it can occur in isolated left- or right-sided heart failure, it is more common in biventricular failure because pleural veins drain both into the systemic and pulmonary venous system. When unilateral, effusions are often right sided.
Symptoms
Heart failure symptoms are traditionally and somewhat arbitrarily divided into “left” and “right” sided, recognizing that the left and right ventricles of the heart supply different portions of the circulation. However, heart failure is not exclusively backward failure (in the part of the circulation which drains to the ventricle).
There are several other exceptions to a simple left-right division of heart failure symptoms. Left sided forward failure overlaps with right sided backward failure. Additionally, the most common cause of right-sided heart failure is left-sided heart failure. The result is that patients commonly present with both sets of signs and symptoms.
Left-sided failure
Backward failure of the left ventricle causes congestion of the pulmonary vasculature, and so the symptoms are predominantly respiratory iature. Backward failure can be subdivided into failure of the left atrium, the left ventricle or both within the left circuit. The patient will have dyspnea (shortness of breath) on exertion (dyspnée d’effort) and in severe cases, dyspnea at rest. Increasing breathlessness on lying flat, called orthopnea, occurs. It is often measured in the number of pillows required to lie comfortably, and in severe cases, the patient may resort to sleeping while sitting up. Another symptom of heart failure is paroxysmal nocturnal dyspnea a sudden nighttime attack of severe breathlessness, usually several hours after going to sleep. Easy fatigueability and exercise intolerance are also common complaints related to respiratory compromise.
“Cardiac asthma” or wheezing may occur.
Compromise of left ventricular forward function may result in symptoms of poor systemic circulation such as dizziness, confusion and cool extremities at rest.
Right-sided failure
Backward failure of the right ventricle leads to congestion of systemic capillaries. This generates excess fluid accumulation in the body. This causes swelling under the skin (termed peripheral edema or anasarca) and usually affects the dependent parts of the body first (causing foot and ankle swelling in people who are standing up, and sacral edema in people who are predominantly lying down). Nocturia (frequent nighttime urination) may occur when fluid from the legs is returned to the bloodstream while lying down at night. In progressively severe cases, ascites (fluid accumulation in the abdominal cavity causing swelling) and hepatomegaly (enlargement of the liver) may develop. Significant liver congestion may result in impaired liver function, and jaundice and even coagulopathy (problems of decreased blood clotting) may occur.
Systolic dysfunction
Heart failure caused by systolic dysfunction is more readily recognized. It can be simplistically described as failure of the pump function of the heart. It is characterized by a decreased ejection fraction (less than 45%). The strength of ventricular contraction is attenuated and inadequate for creating an adequate stroke volume, resulting in inadequate cardiac output. In general, this is caused by dysfunction or destruction of cardiac myocytes or their molecular components. In congenital diseases such as Duchenne muscular dystrophy, the molecular structure of individual myocytes is affected. Myocytes and their components can be damaged by inflammation (such as in myocarditis) or by infiltration (such as in amyloidosis). Toxins and pharmacological agents (such as ethanol, cocaine, doxorubicin, and amphetamines) cause intracellular damage and oxidative stress. The most common mechanism of damage is ischemia causing infarction and scar formation. After myocardial infarction, dead myocytes are replaced by scar tissue, deleteriously affecting the function of the myocardium. On echocardiogram, this is manifest by abnormal or absent wall motion.
Because the ventricle is inadequately emptied, ventricular end-diastolic pressure and volumes increase. This is transmitted to the atrium. On the left side of the heart, the increased pressure is transmitted to the pulmonary vasculature, and the resultant hydrostatic pressure favors extravassation of fluid into the lung parenchyma, causing pulmonary edema. On the right side of the heart, the increased pressure is transmitted to the systemic venous circulation and systemic capillary beds, favoring extravassation of fluid into the tissues of target organs and extremities, resulting in dependent peripheral edema.
Diastolic dysfunction
Heart failure caused by diastolic dysfunction is generally described as the failure of the ventricle to adequately relax and typically denotes a stiffer ventricular wall. This causes inadequate filling of the ventricle, and therefore results in an inadequate stroke volume. The failure of ventricular relaxation also results in elevated end-diastolic pressures, and the end result is identical to the case of systolic dysfunction (pulmonary edema in left heart failure, peripheral edema in right heart failure.)
Diastolic dysfunction can be caused by processes similar to those that cause systolic dysfunction, particularly causes that affect cardiac remodeling.
Diastolic dysfunction may not manifest itself except in physiologic extremes if systolic function is preserved. The patient may be completely asymptomatic at rest. However, they are exquisitely sensitive to increases in heart rate, and sudden bouts of tachycardia (which can be caused simply by physiological responses to exertion, fever, or dehydration, or by pathological tachyarrhythmias such as atrial fibrillation with rapid ventricular response) may result in flash pulmonary edema. Adequate rate control (usually with a pharmacological agent that slows down AV conduction such as a calcium channel blocker or a beta-blocker) is therefore key to preventing decompensation.
Left ventricular diastolic function can be determined through echocardiography by measurement of various parameters such as the E/A ratio (early-to-atrial left ventricular filling ratio), the E (early left ventricular filling) deceleration time, and the isovolumic relaxation time.
Acute Heart Failure
Acute heart failure is defined as the rapid onset of symptoms and signs secondary to abnormal cardiac function. It may occur with or without previous cardiac disease. The cardiac dysfunction can be related to systolic or diastolic dysfunction, to abnormalities in cardiac rhythm, or to pre-load and after-load mismatch. It is often life threatening and requires urgent treatment.
AHF can present itself as acute de novo (new onset of acute heart failure in a patient without previously known cardiac dysfunction) or acute decompensation of chronic heart failure.
The patient with acute heart failure may present with one of several distinct clinical conditions
1. Acute decompensated heart failure (de novo or as decompensation of chronic heart failure) with signs and symptoms of acute heart failure, which are mild and do not fulfil criteria for cardiogenic shock, pulmonary oedema or hypertensive crisis.
2. Hypertensive AHF: Signs and symptoms of heart failure are accompanied by high blood pressure and relatively preserved left ventricular function with a chest radiograph compatible with acute pulmonary oedema.
3. Pulmonary oedema (verified by chest X-ray) accompanied by severe respiratory distress, with crackles over the lung and orthopnoea, with O2 saturation usually <90% on room air prior to treatment.
4. Cardiogenic shock: Cardiogenic shock is defined as evidence of tissue hypoperfusion induced by heart failure after correction of pre-load. There is no clear definition for haemodynamic parameters, which explains the differences in prevalence and outcome reported in studies (Table), but cardiogenic shock is usually characterized by reduced blood pressure (systolic BP <90 mmHg or a drop of mean arterial pressure>30 mmHg) and/or low urine output (<0.5 ml/kg/h), with a pulse rate >60 b.p.m. with or without evidence of organ congestion. There is a continuum from low cardiac output syndrome to cardiogenic shock.
5. High output failure is characterized by high cardiac output, usually with high heart rate (caused by arrhythmias, thyrotoxicosis, anaemia, Paget’s disease, iatrogenic or by other mechanisms), with warm peripheries, pulmonary congestion, and sometimes with low BP as in septic shock.
6. Right heart failure is characterized by low output syndrome with increased jugular venous pressure, increased liver size and hypotension.
Causes and precipitating factors in AHF
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Various other classifications of the acute heart failure syndrome are utilized in coronary care and intensive care units. The Killip classification is based on clinical signs and chest X-ray findings, and the Forrester classification is based on clinical signs and haemodynamic characteristics. These classifications have been validated in acute heart failure after AMI and thus are best applied to acute de novo heart failure. The third ‘clinical severity’ classification has been validated in a cardiomyopathy service and is based on clinical findings. It is most applicable to chronic decompensated heart failure.
The Killip classification was designed to provide a clinical estimate of the severity of myocardial derangement in the treatment of AMI:
· StageI—No heart failure. No clinical signs of cardiac decompensation;
· StageII—Heart failure. Diagnostic criteria include rales, S3 gallop and pulmonary venous hypertension. Pulmonary congestion with wet rales in the lower half of the lung fields;
· StageIII—Severe heart failure. Frank pulmonary oedema with rales throughout the lung fields;
· StageIV—Cardiogenic shock. Signs include hypotension (SBP90mmHg), and evidence of peripheral vasoconstriction such as oliguria, cyanosis and diaphoresis.
The Forrester AHF classification was also developed in AMI patients, and describes four groups according to clinical and haemodynamic status (Figure). Patients are classified clinically on the basis of peripheral hypoperfusion (filliform pulse, cold clammy skin, peripheral cyanosis, hypotension, tachycardia, confusion, oliguria) and pulmonary congestion (rales, abnormal chest X-ray), and haemodynamically on the basis of a depressed cardiac index (2.2 L/min/m2) and elevated pulmonary capillary pressure (>18 mmHg). The original paper defined the treatment strategy according to the clinical and haemodynamic status. Mortality was 2.2% in group I, 10.1% in group II, 22.4% in group III, and 55.5% in group IV.
‘Clinical severity’ classification.
The clinical severity classification is based on observation of the peripheral circulation (perfusion) and on auscultation of the lungs (congestion). The patients can be classified as Class I (Group A) (warm and dry), Class II (Group B) (warm and wet), Class III (Group L) (cold and dry), and Class IV (Group C) (cold and wet). This classification has been validated prognostically in a cardiomyopathy service, and is therefore applicable to patients with chronic heart failure, whether hospitalized or outpatients.
AHF is a clinical syndrome, with reduced cardiac output, tissue hypoperfusion, increase in the pulmonary capillary wedge pressure (PCWP), and tissue congestion. The underlying mechanism may be cardiac or extra-cardiac, and may be transient and reversible with resolution of the acute syndrome, or may induce permanent damage leading to chronic heart failure. The cardiac dysfunction can be related to systolic or diastolic myocardial dysfunction (mainly induced by ischaemia or infection), acute valvular dysfunction, pericardial tamponade, abnormalities of cardiac rhythm, or pre-load/after-load mismatch. Multiple extra-cardiac pathologies may result in acute heart failure by changing the cardiac loading conditions for example (i) increased after-load due to systemic or pulmonary hypertension or massive pulmonary emboli, (ii) increased pre-load due to increased volume intake or reduced excretion due to renal failure or endocrinopathy, or (iii) high output state due to infection, thyrotoxicosis, anaemia, Paget’s disease. Heart failure can be complicated by co-existing end-organ disease. Severe heart failure can also induce multi-organ failure, which may be lethal.
Appropriate long-term medical therapy and, if possible, anatomical correction of the underlying pathology may prevent further AHF syndrome ‘attacks’ and improve the poor long-term prognosis associated with this syndrome.
The clinical pattern
Forward (left and right) AHF. Forward acute heart failure may be mild-to-moderate with only effort fatigue, up to severe with manifestations of reduced tissue perfusion at rest with weakness, confusion, drowsiness, paleness with peripheral cyanosis, cold clammy skin, low blood pressure, filliform pulse, and oliguria, culminating in the full blown presentation of cardiogenic shock.
This syndrome may be induced by a large variety of pathologies. An adequate history may indicate the main diagnosis for example (i) acute coronary syndrome with the relevant risk factors, past history, and suggestive symptoms; (ii) acute myocarditis with a recent history suggestive of acute viral infection; (iii) acute valvular dysfunction with a history of chronic valve disease or valve surgery, infection with the possibility of bacterial endocarditis, or chest trauma; (iv) pulmonary embolism with a relevant history and suggestive symptoms; or (v) pericardial tamponade.
Physical examination of the cardiovascular system may be indicative of the main diagnosis, for example by distended neck veins and paradoxical pulse (pericardial tamponade), muffled heart sounds related to myocardial systolic dysfunction, or the disappearance of artificial valve sounds or an appropriate murmur indicating a valvular problem.
In forward AHF immediate management should include supportive treatment to improve cardiac output and tissue oxygenation. This can be achieved with vasodilating agents, fluid replacement to achieve an optimal pre-load, short-term inotropic support and (sometimes) intra-aortic balloon counterpulsation.
Left-heart failure Left-heart backward failure may be related to left ventricular dysfunction with varying degrees of severity, from mild-to-moderate with only exertional dyspnoea, to pulmonary oedema presenting with shortness of breath (dry cough, sometimes with frothy sputum), pallor or even cyanosis, cold clammy skin, and normal or elevated blood pressure. Fine rales are usually audible over the lung fields. Chest X-ray shows pulmonary congestion/oedema.
Pathology of the left heart may be responsible for this syndrome, including: myocardial dysfunction related to chronic existing conditions; acute insult such as myocardial ischaemia or infarction; aortic and mitral valve dysfunction; cardiac rhythm disturbances; or tumours of the left heart. Extra-cardiac pathologies may include severe hypertension, high output states (anaemia, thyrotoxicosis) and neurogenic states (brain tumours or trauma).
Physical examination of the cardiovascular system, including the apex beat, the quality of the heart sounds, the presence of murmurs, and auscultation of the lungs for fine rales and expiratory wheezing (‘cardiac asthma’) may be indicative of the main diagnosis.
In left heart backward failure patients should be treated mainly with vasodilation and the addition of diuretics, bronchodilators and narcotics, as required. Respiratory support may be necessary. This can either be with continuous positive airway pressure (CPAP) or non-invasive positive pressure ventilation, or in some circumstances invasive ventilation may be required following endotracheal intubation.
Right-heart failure. The syndrome of acute right heart failure is related to pulmonary and right heart dysfunction, including exacerbations of chronic lung disease with pulmonary hypertension, or acute massive lung disease (e.g. massive pneumonia or pulmonary embolism), acute right ventricular infarction, tricuspid valve malfunction (traumatic or infectious), and acute or sub-acute pericardial disease. Advanced left heart disease progressing to right-sided failure should also be considered, and similarly long-standing congenital heart disease with evolving right ventricular failure should be taken into account. Non-cardiopulmonary pathologies include nephritic/nephrotic syndrome and end-stage liver disease. Various vasoactive peptide-secreting tumours should also be considered.
The typical presentation is with fatigue, pitting ankle oedema, tenderness in the upper abdomen (due to liver congestion), shortness of breath (with pleural effusion) and distension of the abdomen (with ascites). The full-blown syndrome includes anasarca with liver dysfunction and oliguria.
Diagnosis of AHF
Imaging
Echocardiography is commonly used to support a clinical diagnosis of heart failure. This modality uses ultrasound to determine the stroke volume (SV, the amount of blood in the heart that exits the ventricles with each beat), the end-diastolic volume (EDV, the total amount of blood at the end of diastole), and the SV in proportion to the EDV, a value known as the ejection fraction (EF). In pediatrics, the shortening fraction is the preferred measure of systolic function. Normally, the EF should be between 50% and 70%; in systolic heart failure, it drops below 40%. Echocardiography can also identify valvular heart disease and assess the state of the pericardium (the connective tissue sac surrounding the heart). Echocardiography may also aid in deciding what treatments will help the patient, such as medication, insertion of an implantable cardioverter-defibrillator or cardiac resynchronization therapy. Echocardiography can also help determine if acute myocardial ischemia is the precipitating cause, and may manifest as regional wall motion abnormalities on echo.
Chest X-rays are frequently used to aid in the diagnosis of CHF. In the compensated patient, this may show cardiomegaly (visible enlargement of the heart), quantified as the cardiothoracic ratio (proportion of the heart size to the chest). In left ventricular failure, there may be evidence of vascular redistribution (“upper lobe blood diversion” or “cephalization”), Kerley lines, cuffing of the areas around the bronchi, and interstitial edema.
Angiography
Heart failure may be the result of coronary artery disease, and its prognosis depends in part on the ability of the coronary arteries to supply blood to the myocardium (heart muscle). As a result, coronary catheterization may be used to identify possibilities for revascularisation through percutaneous coronary intervention or bypass surgery.
The diagnosis of AHF is based on the symptoms and clinical findings, supported by appropriate investigations such as ECG, chest X-ray, biomarkers, and Doppler-echocardiography (Figure). The patient should be classified according to previously described criteria for systolic and/or diastolic dysfunction (Figure), and by the characteristics of forward or backward left or right heart failure.
Figure Diagnosis of AHF.
Figure Assessment of LV function in AHF.
History and physical examination should confirm the syndrome of acute right heart failure, indicate the suspected diagnosis and guide further investigation, which is likely to include ECG, blood gases, D-dimer, chest X-ray, cardiac Doppler-echocardiography, angiography or chest CT scan.
In right heart backward failure fluid overload is managed with diuretics, including spironolactone, and sometimes with a short course of low dose (‘diuretic dose’) of dopamine. Concomitant treatment may include: antibiotics for pulmonary infection and bacterial endocarditis; Ca++ channel blockers, nitric oxide, or prostaglandins for primary pulmonary hypertension; and anticoagulants, thrombolytics, or thrombectomy for acute pulmonary embolism.
Tachycardia and hypotension are described with high-dose levosimendan infusion and it is not currently recommended in patients with a systolic blood pressure <85 mmHg. Levosimendan has not been associated with an increased frequency of malignant arrhythmias in comparative trials with either placebo, or dobutamine. Reductions in the haematocrit, haemoglobin, and plasma potassium, likely secondary to vasodilation and secondary neurohumoral activation, have been described and seem to be dose-dependent.
Laboratory tests
A number of laboratory tests should be performed in AHF patients (Table). Arterial blood gas analysis (Astrup) enables assessment of oxygenation (pO2), respiratory adequacy (pCO2), acid–base balance (pH), and base deficit, and should be performed in all patients with severe heart failure. Non-invasive measurement with pulse oximetry and end-tidal CO2 can often replace Astrup (Level of evidence C) but not in very low output, vasocontricted shock states. Measurement of venous O2 saturation (i.e. in the jugular vein) may be useful for an estimation of the total body oxygen supply-demand balance.
Table Laboratory tests in patients hospitalized with AHF
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Other specific laboratory tests should be taken for differential diagnostic purposes or in order to identify end-organ dysfunction.
INR=international normalized ratio of thromboplastin time; TnI=troponin I; TnT=troponin T.
Plasma B-type natriuretic peptide (BNP) is released from the cardiac ventricles in response to increased wall stretch and volume overload and has been used to exclude and/or identify congestive heart failure (CHF) in patients admitted, for dyspnoea, to the emergency department. Decision cut points of 300 pg/mL for NT-proBNP and 100 pg/mL for BNP have been proposed, but the older population has been poorly studied. During ‘flash’ pulmonary oedema, BNP levels may remaiormal at the time of admission. Otherwise, BNP has a good negative predictive value to exclude heart failure. Various clinical conditions may affect the BNP concentration including renal failure and septicaemia. If elevated concentrations are present, further diagnostic tests are required. If AHF is confirmed, increased levels of plasma BNP and NT-pro BNP carry important prognostic information. The exact role of BNP remains to be fully clarified.
Echocardiography is an essential tool for the evaluation of the functional and structural changes underlying or associated with AHF, as well as in the assessment of acute coronary syndromes.
Echocardiography with Doppler imaging should be used to evaluate and monitor regional and global left and right ventricular function, valvular structure and function, possible pericardial pathology, mechanical complications of acute myocardial infarction and—on rare occasions—space occupying lesions. Cardiac output can be estimated by appropriate Doppler aortic or pulmonary time velocity contour measurements. An appropriate echo-Doppler study can also estimate pulmonary artery pressures (from the tricuspid regurgitation jet) and has also been used for the monitoring of left ventricular pre-load. Echocardiography has not been validated with right heart catheterization in patients with AHF.
In cases of coronary-artery-related complications such as unstable angina or myocardial infarction, angiography is important and angiography-based revascularization therapy has been shown to improve prognosis.
Treatment.
Vasopressor therapy in cardiogenic shock When the combination of inotropic agent and fluid challenge fails to restore adequate arterial and organ perfusion despite an improvement in cardiac output, therapy with vasopressors may be required. Vasopressors may also be used, in emergencies, to sustain life and maintain perfusion in the face of life-threatening hypotension. Since cardiogenic shock is associated with high vascular resistances, any vasopressor should be used with caution and only transiently, because it may increase the after-load of a failing heart and further decrease end-organ blood flow.
Epinephrine is a catecholamine with high affinity for ß1, ß2, and receptors. Epinephrine is used generally as an infusion at doses of 0.05 to 0.5 µg/kg/min when dobutamine refractoriness is present and the blood pressure remains low. Direct arterial pressure monitoring and monitoring of haemodynamic response by PAC is recommended.
Oxygen and ventilatory assistance
The maintenance of an SaO2 within the normal range (95–98%) is important in order to maximize oxygen delivery to the tissues and tissue oxygenation, thus helping to prevent end-organ dysfunction and multiple organ failure.
European Society of Cardiology Guidelines for the Diagnosis and Treatment of Chronic Heart Failure
Another objective of treatment is reduction in the clinical signs of HF. A reduction in body weight, and/or an increase in diuresis, are beneficial effects of therapy in congestive and oliguric patients with AHF. Similarly, an improvement in oxygen saturation, renal and/or hepatic function, and/or serum electrolytes are meaningful goals of treatment. Plasma BNP concentration can reflect haemodynamic improvement and decreased levels are beneficial.
Beneficial effects of therapy on outcome include reductions in the duration of intravenous vasoactive therapy, the length of stay, and the readmission rate with an increase in the time to readmission. A reduction in both in-hospital and long-term mortality is also a major goal of treatment.
Lastly, a favourable safety and tolerability profile is also necessary for any treatment used in patients with AHF. Any agent used in this condition should be associated with a low withdrawal rate with a relatively low incidence of untoward side effects.
Chronic Heart Failure
Сauses. The predominance of causes of heart failure are difficult to analyze due to challenges in diagnosis, differences in populations, and changing prevalence of causes with age.
A 19 year study of 13000 healthy adults in the United States (the National Health and Nutrition Examination Survey (NHANES I) found the following causes ranked by Population Attributable Risk score:
1. Ischaemic heart disease 62%
2. Cigarette smoking 16%
3. Hypertension (high blood pressure)10%
4. Obesity 8%
5. Diabetes 3%
6. Valvular heart disease 2% (much higher in older populations).
An Italian registry of over 6200 patients with heart failure showed the following underlying causes
1. Ischaemic heart disease 40%
2. Dilated cardiomyopathy 32%
3. Valvular heart disease 12%
4. Hypertension 11%
5. Other 5%.
Rarer causes of heart failure include:
· Viral myocarditis (an infection of the heart muscle)
· Infiltrations of the muscle such as amyloidosis
· HIV cardiomyopathy (caused by human immunodeficiency virus)
· Connective tissue diseases such as systemic lupus erythematosus
· Abuse of drugs such as alcohol and cocaine
· Pharmaceutical drugs such as chemotherapeutic agents
· Arrhythmias.
Clinical pattern. Presentation can be non-specific and mimicked by many other disease states, especially in elderly people. Unsurprisingly, sensitivity and specificity of frequent presenting symptoms of heart failure are rather poor. Signs of heart failure—such as raised jugular venous pulse, a third heart sound, basal pulmonary crackles, and sinus tachycardia—have somewhat greater specificity for a heart failure diagnosis than do symptoms, at least in some assessments.
Main clinical symptoms of CHF
Swelling of jugular veins
Diagnostics. Routine objective testing methods, such as electrocardiograms (ECGs) and chest radiographs, are also fairly non-specific. The ECG is, however, a reasonable rule-out test for systolic dysfunction—ie, this diagnosis is somewhat unlikely if the ECG is entirely normal.
Laboratory testing can provide useful information about cause of heart failure, disease severity, and prognosis. Such data are especially valuable if important comorbid disorders (eg, anaemia, hyponatraemia, renal dysfunction, and diabetes) are also present.
Echocardiography is a useful method to assist in diagnosis of heart failure. This modality can provide important information about left-ventricular dimensions and geometry, extent of systolic dysfunction, whether dysfunction is global or segmental, the status of valve apparatus, and estimates of pulmonary pressures. Echocardiography is most specific for diagnosis of left-ventricular systolic dysfunction. Conversely, assessment of diastolic dysfunction remains elusive, even with the advent of tissue doppler imaging, a technique that provides important information on patterns of diastolic relaxation and filling. Tissue doppler imaging can also provide data on ventricular dyssynchrony.
New imaging modalities such as MRI, especially with gadolinium contrast, provide great precision for assessment of ventricular structure and function. However, use of MRI to measure progression of established heart failure is limited by presence of device hardware in many patients.
Measurement of amounts in plasma of either B-type natriuretic peptide (BNP) or its precursor, N terminal-proBNP, has aided diagnosis of heart failure. In patients presenting with acute dyspnoea, area under the receiver-operating characteristic curve is 0·90, indicating relatively high sensitivity and specificity for this peptide compared with the gold standard of diagnosis by a cardiologist on the basis of available clinical information. Low BNP has very high negative predictive value, making it a useful rule-out test, particularly in populations in which frequency of heart failure is expected to be high. By contrast, use of BNP for community-based screening of presence of left-ventricular dysfunction can be complicated by low background disease prevalence.Clinical use of BNP for diagnosis of heart failure has been criticised, in that patients with high concentrations of this peptide typically have classic signs, symptoms, and laboratory values greatly indicative of the disorder—ie, an accurate diagnosis can be made on clinical grounds. For individuals in whom a diagnosis of heart failure is less clear, BNP amounts often fall within an uncertain grey zone. The usefulness of this peptide is lessened by the fact that amounts are raised with advanced age, female sex, and renal impairment and are lowered with obesity. Nevertheless, plasma BNP testing is emerging as a useful aid for diagnosis of heart failure.
Signs of congestion in the lungs on X-ray
T
This chest radiograph shows an enlarged cardiac silhouette and edema at the lung bases, signs of acute heart failure.
Treatment commonly consists of lifestyle measures such as smoking cessation, light exercise including breathing protocols, decreased salt intake and other dietary changes, and medications. Sometimes it is treated with implanted devices (pacemakers or ventricular assist devices) and occasionally a heart transplant. Treatment of established systolic chronic heart failure includes use of agents that block the renin-angiotensin-aldosterone and sympathetic nervous systems to prevent adverse remodelling, to reduce symptoms and prolong survival. Diuretics are used to achieve and maintain euvolaemia. Devices have a key role in management of advanced heart failure and include cardiac resynchronisation in patients with evidence of cardiac dyssynchrony and implantation of a cardioverter defibrillator in individuals with low ejection fraction. Approaches for treatment of acute heart failure and heart failure with preserved ejection fraction are supported by little clinical evidence. Emerging strategies for heart failure management include individualisation of treatment, novel approaches to diagnosis and tracking of therapeutic response, pharmacological agents aimed at new targets, and cell-based and gene-based methods for cardiac regeneration.
Chronic management
The goal is to prevent the development of acute decompensated heart failure, to counteract the deleterious effects of cardiac remodeling, and to minimize the symptoms that the patient suffers. First-line therapy for all heart failure patients is angiotensin-converting enzyme (ACE) inhibition. ACE inhibitors (i.e., enalapril, captopril, lisinopril, ramipril) improve survival and quality of life in heart failure patients, and have been shown to reduce mortality in patients with left ventricular dysfunction iumerous randomized trials.[33][34] In addition to pharmacologic agents (oral loop diuretics, beta-blockers, ACE inhibitors or angiotensin receptor blockers, vasodilators, and in severe cardiomyopathy aldosterone receptor antagonists), behavioral modification should be pursued, specifically with regard to dietary guidelines regarding salt and fluid intake. Exercise should be encouraged as tolerated, as sufficient conditioning can significantly improve quality-of-life.
Anemia is an independent factor in mortality in people with chronic heart failure; it may also impact on quality of life.[35] Treatment of anaemia improves quality of life and decreases mortality rates.[36]
In patients with severe cardiomyopathy, implantation of an automatic implantable cardioverter defibrillator (AICD) should be considered. A select population will also probably benefit from ventricular resynchronization.
In select cases, cardiac transplantation can be considered. While this may resolve the problems associated with heart failure, the patient generally must remain on an immunosuppressive regimen to prevent rejection, which has its own significant downsides.
Home dobutamine and milrinone
These two medications are both inotropes with sympathomimetic effect. Both can be used in severe heart failure, generally in patients who require frequent exacerbations with hospitalization and/or refractory symptoms. While both medications have proven to improve symptoms, both also increase the risk of sudden cardiac death, and the research suggests an increased mortality rate for patients who are started on these medications. Extensive counseling about symptom management vs. risk of earlier death needs to be undertaken before starting the medication.[
Palliative care
Patients with CHF often have significant symptoms, such as shortness of breath and chest pain. Both palliative care and cardiology are trying to get palliative care involved earlier in the course of patients with heart failure, and some would argue any patient with NYHA class III CHF should have a palliative care referral. Palliative care caot only provide symptom management, but also assist with advanced care planning, goals of care in the case of a significant decline, and making sure the patient has a medical power of attorney and discussed his or her wishes with this individual.Hospice
Without transplantation, heart failure may not be reversible and cardiac function typically deteriorates with time. The growing number of patients with Stage IV heart failure (intractable symptoms of fatigue, shortness of breath or chest pain at rest despite optimal medical therapy) should be considered for palliative care or hospice, according to American College of Cardiology/American Heart Association guidelines.
Considerable advances have been made in management of heart failure over the past few decades. In outpatient-based clinical trials, mortality has more than halved in people with established systolic chronic heart failure; moreover, admissions have fallen and patients’ quality of life has risen. Nevertheless, heart failure remains a major public-health issue, with high prevalence and poor outcomes. Management of this condition includes appropriate non-pharmacological strategies, use of drugs (particularly those that inhibit key activated neurohormonal systems), and implantation of devices in appropriate patients. Surgery and transplantation are also options for selected individuals with highly advanced disease.
Despite the promise of new drugs, cell-based therapeutic approaches, and novel devices, a reduction of disease burden is likely to come from preventive strategies. The antecedents to heart failure are well known; enhanced diagnostic precision coupled with early intervention could lessen the burden of disease.
Treatment of Patients with Stage A Heart Failure
Control of risk factors in stage A (e.g., hypertension, coronary artery disease, and diabetes mellitus) has a favorable effect on the incidence of later cardiovascular events. Results from trials have shown that the effective treatment of hypertension decreases the occurrence of left ventricular hypertrophy and cardiovascular mortality, as well as reducing the incidence of heart failure by 30 to 50 percent. Guidelines have recommended that the target for diastolic blood pressure in patients considered to be at high risk, particularly those with diabetes, be below 80 mm Hg, with the goal of further reducing morbidity and mortality. Patients with diabetes have a high incidence of heart disease, with multiple adaptive and maladaptive biochemical and functional cardiac abnormalities.42 ACE-inhibitor treatment of asymptomatic high-risk patients with diabetes or vascular disease and no history of heart failure has yielded significant reductions in the rates of death, myocardial infarction, and stroke. The use of the angiotensin-receptor blocker losartan has been shown to delay the first hospitalization for heart failure in patients with diabetes mellitus and nephropathy. In short, the goal of treatment in stage A is to prevent remodeling.
Stages of Heart Failure and Treatment Options for Systolic Heart Failure.
Patients with stage A heart failure are at high risk for heart failure but do not have structural heart disease or symptoms of heart failure. This group includes patients with hypertension, diabetes, coronary artery disease, previous exposure to cardiotoxic drugs, or a family history of cardiomyopathy. Patients with stage B heart failure have structural heart disease but have no symptoms of heart failure. This group includes patients with left ventricular hypertrophy, previous myocardial infarction, left ventricular systolic dysfunction, or valvular heart disease, all of whom would be considered to have New York Heart Association (NYHA) class I symptoms. Patients with stage C heart failure have known structural heart disease and current or previous symptoms of heart failure. Their symptoms may be classified as NYHA class I, II, III, or IV. Patients with stage D heart failure have refractory symptoms of heart failure at rest despite maximal medical therapy, are hospitalized, and require specialized interventions or hospice care. All such patients would be considered to have NYHA class IV symptoms. ACE denotes angiotensin-converting enzyme, ARB angiotensin-receptor blocker, and VAD ventricular assist device.
Treatment of Stage B, C, or D Heart Failure with or without Symptoms
The goals of therapy for patients with heart failure and a low ejection fraction are to improve survival, slow the progression of disease, alleviate symptoms, and minimize risk factors. Modifications of lifestyle can be helpful in controlling the symptoms of heart failure. For example, basic habits of moderate sodium restriction, weight monitoring, and adherence to medication schedules may aid in avoiding fluid retention or alerting the patient to its presence. Moderation of alcohol intake is advised; avoidance of nonsteroidal antiinflammatory drugs (NSAIDs) is also important. NSAIDs have been associated with an increase in the incidence of new heart failure, decompensated chronic heart failure, and hospitalizations for heart failure. For selected patients, a regularly scheduled exercise program may have beneficial effects on symptoms. ACE inhibitors decrease the conversion of angiotensin I to angiotensin II, thereby minimizing the multiple pathophysiological effects of angiotensin II, and decrease the degradation of bradykinin. Bradykinin promotes vasodilatation in the vascular endothelium and causes natriuresis in the kidney. The beneficial effects of ACE inhibitors in heart failure and after a myocardial infarction include improvements in survival, the rate of hospitalization, symptoms, cardiac performance, neurohormonal levels, and reverse remodeling.
ACE inhibitors have not been unequivocally shown to reduce the incidence of sudden death. They are recommended for many patients with stage A heart failure and all patients with stage B, stage C, or stage D heart failure. But unresolved issues persist. First, underuse of ACE inhibitors by physicians for fear of potential side effects has been a concern. Yet side effects are fairly predictable and reversible and can usually be successfully managed. Second, the optimal dose of an ACE inhibitor is uncertain. Most randomized trials have showo difference in mortality between patients receiving high-dose ACE inhibitors and those receiving low-dose ACE inhibitors. Finally, it is uncertain whether there are any meaningful differences among the many ACE inhibitors available today.
Beta-blockers have long been used for the treatment of hypertension, angina, and arrhythmias and for prophylaxis in patients who have had a myocardial infarction. This class of medication has had a remarkable effect on chronic heart failure. The primary action of beta-blockers is to counteract the harmful effects of the sympathetic nervous system that are activated during heart failure. The beneficial effects of these drugs have been demonstrated in trials involving patients with heart failure from various causes and of all stages. These effects include improvements in survival, morbidity, ejection fraction, remodeling, quality of life, the rate of hospitalization, and the incidence of sudden death. Beta-blockers should be used in all patients in stable condition without substantial fluid retention and without recent exacerbations of heart failure requiring inotropic therapy. There are a few populations of patients in whom beta-blockers should not be used or should be used only with extreme caution. Such patients include those with reactive airway disease, those with diabetes in association with frequent episodes of hypoglycemia, and those with bradyarrhythmias or heart block who do not have a pacemaker.
Although the short-term effects of beta-blockers may result in a temporary exacerbation of symptoms, their long-term effects are uniformly beneficial. Placebo-controlled trials involving long-term treatment have shown improved systolic function after three months of treatment and reverse remodeling after four months. In the United States, two beta-blockers are specifically approved for the treatment of heart failure: carvedilol and long-acting metoprolol. Currently, neither drug has proved to be consistently superior; both have shown significant clinical efficacy. Carvedilol is a nonselective -adrenergic antagonist with alpha-blocking effects; metoprolol is a selective 1-adrenergic antagonist with no alpha-blocking effects. A large trial comparing these drugs is nearing completion. However, the most frequently prescribed beta-blocker in the United States is atenolol; there have beeo studies to date on the use of atenolol in patients with heart failure. Drugs that antagonize the sympathetic nervous system through alternative pathways, such as clonidine or moxonidine, have been less clinically useful in patients with heart failure.
Available angiotensin-receptor antagonists block the effects of angiotensin II at the angiotensin II subtype 1 receptor. The recently published guidelines recommend that these drugs should not be used as first-line therapy for heart failure of any stage but should be used only in patients who cannot tolerate ACE inhibitors because of severe cough or angioedema. Several trials involving patients with heart failure have shown that angiotensin-receptor antagonists have efficacy similar to that of ACE inhibitors but are not superior. On the other hand, in a randomized trial of patients with symptomatic left ventricular systolic dysfunction, the addition of valsartan to ACE-inhibitor treatment reduced the rate of the combined end point of death or cardiovascular events and improved clinical signs and symptoms of heart failure. However, patients who were receiving beta-blockers, an ACE inhibitor, and the angiotensin-receptor blocker valsartan had more adverse events and increased mortality. More recently, the Losartan Intervention for Endpoint Reduction in Hypertension (LIFE) trial was completed in patients with stage B heart failure — specifically, asymptomatic patients with hypertension and left ventricular hypertrophy on electrocardiography. Treatment with the angiotensin-receptor blocker losartan yielded improvements in cardiovascular morbidity and survival, as well as a decrease in the incidence of new-onset diabetes, as compared with treatment with the beta-blocker atenolol.Thus, accumulating data lend support to the contention that angiotensin-receptor antagonists are a reasonable alternative to ACE inhibitors.
Additional Therapy for Symptomatic Patients with Stage C or Stage D Heart Failure
There is evidence to support the use of spironolactone, an aldosterone antagonist, in patients with advanced symptoms of heart failure — specifically, NYHA class III or IV symptoms. In patients with advanced heart failure, circulating levels of aldosterone become elevated in response to stimulation by angiotensin II, and there is a decrease in the hepatic clearance of aldosterone due to hepatic congestion. Aldosterone stimulates the retention of salt, myocardial hypertrophy, and potassium excretion; spironolactone counteracts these responses. The beneficial effects of spironolactone in heart failure may also include a decrease in collagen synthesis that promotes organ fibrosis.
Since heart failure is a salt-avid syndrome resulting in intravascular volume overload, diuretics are a mainstay for controlling symptoms of congestion. Thiazide or loop diuretics are often prescribed, and combination therapy may be used to promote effective diuresis in advanced cases.
It is only within the past five years that a large, randomized, placebo-controlled study of digoxin for symptomatic patients with a low ejection fraction has been completed. There was no difference in mortality between patients receiving digoxin and patients receiving placebo, but there were decreases in the digoxin group in the rates of worsening heart failure and hospitalization. Recent data suggest that the maintenance of a low serum digoxin concentration (<0.09 ng per milliliter) is as effective in reducing the rate of cardiovascular events as the maintenance of a higher concentration and is associated with a lower rate of toxic effects. Elderly patients and those with renal insufficiency are more prone to toxic effects. There is a commonly observed and clinically important interaction between digoxin and amiodarone: digoxin levels can become markedly elevated after the introduction of amiodarone.
There are some patients who cannot tolerate either ACE inhibitors or angiotensin-receptor blockers, usually because of hyperkalemia or renal insufficiency. In such patients who remain symptomatic despite diuretic and beta-blocker therapy, treatment with the vasodilator combination of hydralazine and isosorbide dinitrate may be an option.
Revascularization and Surgical Therapy
Patients with heart failure of any stage who are at risk for coronary artery disease should be screened for myocardial ischemia. Revascularization, through either a catheter-based or a surgical approach, often improves ischemic symptoms, improves cardiac performance, and reduces the risk of sudden death. Patients with stage C or stage D heart failure, who have heretofore been considered unacceptable candidates for surgery, may in fact derive substantial benefit from bypass surgery and additional techniques designed to reduce myocardial wall stress. Procedures to eliminate or exclude areas of infarction, repair mitral regurgitation, or support the failing myocardium are undergoing clinical trials.Similarly, the role of mechanical devices that serve to support patients who are awaiting heart transplantation or are definitive therapy for end-stage (stage D) heart failure continues to evolve, and such devices offer great hope to many patients who are not eligible for cardiac transplantation.
Acute vascular insufficiency
What is fainting?
Fainting is a loss of consciousness that occurs from a loss of, or decreased amount of, blood supply to the brain. It may be preceded by the sensation of feeling lightheaded or unsteady, as if you will lose your balance, or a feeling that things are spinning around you. Fainting and dizziness may be accompanied by other symptoms, such as nausea with or without vomiting, perspiration, and trembling.
Circulatory shock, commonly known simply as shock, is a life-threatening medical condition that occurs due to inadequate substrate for aerobic cellular respiration.[1] In the early stages this is generally an inadequate tissue level of oxygen
The typical signs of shock are low blood pressure, a rapid heartbeat and signs of poor end-organ perfusion or “decompensation/peripheral shut down” (such as low urine output, confusion or loss of consciousness). There are times that a person’s blood pressure may remain stable, but may still be in circulatory shock, so it is not always a sign.
Circulatory shock should not be confused with the emotional state of shock, as the two are not related. Circulatory shock is a life-threatening medical emergency and one of the most common causes of death for critically ill people. Shock can have a variety of effects, all with similar outcomes, but all relate to a problem with the body’s circulatory system. For example, shock may lead to hypoxemia (a lack of oxygen in arterial blood) or cardiac arrest.
