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Ashley EA, Niebauer J. Cardiology Explained. London: Remedica; 2004.

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Cardiology Explained.

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Chapter 9Valve disease

Disease of the heart valves remains an important cause of morbidity and mortality across the world. While advances in echocardiography and the widespread availability of antibiotics have changed the prevalence, management, and especially the diagnosis of valve disease for specialists, very little has changed for generalists, who hear heart murmurs less frequently. Even though echo diagnosis is not readily available to generalists, they nevertheless feel pressured to identify murmurs and to report them, with their associated signs, in the referral letter. Similarly, for many examiners, the appeal of obscure murmurs for clinical short-case exams remains too great to resist, despite its mostly historical relevance. Yet, there are few greater pleasures in clinical medicine than having your stethoscopic diagnostic brilliance confirmed by an echo report. Furthermore, healthcare economics has prompted a renewed interest in the power of the stethoscope for diagnosing and even quantifying valve disease.

The asymptomatic murmur

Opinions differ as to the management of a murmur that has been picked up incidentally. By far the most common is the mid systolic 2/6 murmur (grade II – see Table 1). For children and young adults with an asymptomatic mid systolic murmur, a negative history and a negative physical exam are sufficient to exclude sinister pathology in most cases.

Table 1. Grading of murmurs.

Table 1

Grading of murmurs.

In the elderly, it is important to differentiate between the common and benign aortic sclerosis and the less common and less benign aortic stenosis (AS). As such, close attention should be paid to the cardiac exam. In particular, AS is indicated by:

  • murmur radiation
  • the presence of a thrill
  • a soft second heart sound

In addition, an electrocardiogram should be carried out to screen for left ventricular hypertrophy (LVH), ischemia, and atrial size or conduction abnormalities. If none of the above is present and the patient remains asymptomatic, the most likely diagnosis is aortic sclerosis and no echo is required.

Referral is warranted when a murmur in an asymptomatic patient is:

  • systolic and grade III or above
  • late systolic
  • mid systolic and accompanied by clinical signs suggestive of AS
  • diastolic
  • continuous

Aortic stenosis

Causes

Congenital aortic stenosis

Congenital AS is usually due to a bicuspid valve. A bicuspid valve in itself does not give rise to significant hemodynamic abnormality, but it has a tendency to calcify and a predisposition to infective endocarditis (see Table 2).

Table 2. Clinical signs in aortic stenosis and aortic regurgitation.

Table 2

Clinical signs in aortic stenosis and aortic regurgitation.

Rheumatic aortic stenosis

Rheumatic AS results from cusp fusion and calcification many years following rheumatic fever.

Senile aortic stenosis

Senile, or degenerative, AS results from calcium deposition on the aortic surface of the valve. This is becoming an increasingly important disability problem in the elderly.

Physical signs

  • The carotid pulse is slow rising with reduced amplitude.
  • The venous pressure is usually normal until late in the disease.
  • The apex beat is sustained and can be doubled due to an additional atrial component.
  • On auscultation, the second heart sound is single when the valve is calcified due to a lack of aortic component. The classic ejection systolic murmur, which can radiate to one or both carotids, is usually heard best over the aortic area. A soft, early diastolic murmur of aortic regurgitation (AR) often coexists.

Investigation and management

Echo is the diagnostic tool of choice for valve disease – in particular, Doppler measurement of valve gradients can quantify lesions. Significant hemodynamic changes do not occur until the aortic valve area has been reduced to a quarter of its normal size (the normal orifice is 3–4 cm2). AS is classed as:

  • mild if the area is >1.5 cm2
  • moderate if the area is 1–1.5 cm2
  • severe if the area is <1 cm2

The Invention of the Stethoscope

"In the summer of 1816, Laennec was called to a young lady who presented the general symptoms of disease of the heart; the application of the hand to the chest and percussion afforded very little assistance, and immediate auscultation was interdicted by the sex and embonpointa of the patient. The recollection of the well-known fact, that the tap of a pin at one end of a beam could be heard distinctly at the opposite end, induced him at the moment, to avail himself of this acoustic phenomenon. He took a quire of paper, rolled it tightly together, applied one extremity over the region of the heart, and putting the ear to the other, was surprised to find that he could distinguish the pulsation of the heart in a more distinct manner than he could before do with the naked ear. Having hit upon the principle he extended its application to the investigation of the various sounds produced in the chest by the respiration, the voice, and the accidental presence of fluids in the lung, pleural sac, and pericardium."

Mediate Auscultation, 1816. (Quoted in The Lancet 1998;352:997.)

aCorpulence, physically bulky.

Severe stenosis causes a transvalvular pressure gradient of >50 mm Hg in the presence of normal transvalvular flow (ie, normal LV function). However, abnormally low pressure gradients are found in conditions of LV dysfunction, so the gradient alone is not a clear guide.

The natural history of AS is one of slow progression. Studies suggest that some patients exhibit a decrease in valve area of 0.1–0.3 cm2/year, although no progression is discernible in many patients. However, regardless of the individual variability, symptoms of angina, syncope, or heart failure generally develop after a latent period. At this point, the outlook changes dramatically. After the onset of symptoms, the average survival is less than 3 years. Thus, development of symptoms is the critical point in the natural history of AS and thereafter the benefits of surgery outweigh the risk. Consequently, asymptomatic AS patients should be monitored closely. Although there is no clear consensus, most cardiologists follow-up mild AS annually (together with 5-yearly echos); moderate AS every 6 months (together with 2-yearly echos); and severe AS more frequently (together with annual echos). If a patient with AS presents with a change in symptoms, their next appointment at the cardiology clinic should be expedited.

If a patient with severe AS is undergoing open chest bypass grafting for coexisting coronary artery disease (CAD), the opportunity should be taken to carry out aortic valve replacement (AVR) – regardless of whether or not AS symptoms are evident. The merit of carrying out a concomitant AVR is less clear for those with mild or moderate AS.

Cardiac catheterization is only indicated in AS for two reasons: (1) to perform coronary angiography before AVR in patients with risk factors for CAD; (2) to assess the severity of AS in symptomatic patients when AVR is planned or when noninvasive tests are inconclusive (catheterization allows accurate quantification of the orifice because it can account for transvalvular flow).

Contrary to popular belief, exercise testing is not contraindicated for mild to moderate AS patients and can give useful information with respect to exercise capacity, heart rate recovery, and exercise-induced rise in blood pressure.

Balloon valvotomy

Percutaneous balloon aortic valvotomy (stretching a stenotic valve by balloon inflation) has an important role to play in the treatment of young adults with AS, but a very limited role in older patients. This is because the postoperative valve area is rarely >1 cm2 and because complications are frequent (10%) and serious. This procedure can act as a "bridge" to reduce the requirement for surgery (with its inherent risk) in adult patients with refractory pulmonary edema or cardiogenic shock.

Aortic valve replacement in the elderly

Due to the limitations of medical therapy and balloon valvotomy, AVR should be considered for all elderly patients with symptomatic AS. However, the decision as to whether to carry out AVR is rarely straightforward and must take into account the risks as viewed by both the surgeon and the patient. Comorbidity in the form of LVH or CAD greatly increases the risk associated with surgery. In addition, specific valve problems, such as heavy calcification and narrow LV outflow tract or annulus, make the procedure more complex. The decision is highly individual.

Aortic regurgitation

AR is associated with classic clinical signs (see Table 2):

  • waterhammer (collapsing) pulse – detected by comparing the character of the radial pulse at the level of the heart with its character on elevation of the arm (use several fingers). Elevation accentuates the steep rise-and-fall character of this pulse, which seems to slap faster and harder against the fingers
  • Corrigan's sign – visible arterial pulsation in the neck
  • de Musset's sign – nodding of the head in time with the heartbeat
  • Duroziez's sign – caused by retrograde diastolic flow in the femoral artery. Place the stethoscope on the femoral pulse and occlude the artery distally. The turbulent flow will be picked up as a "to-and-fro" murmur
  • Quincke's sign – capillary pulsation in the nail beds that is visible on applying gentle pressure to induce a degree of whitening
  • Traube's sign – a "pistol-shot" sound heard over the femoral pulse
  • Müller's sign – pulsation of the uvula

An early diastolic murmur is heard at the left lower sternal edge when the patient is sitting forward and holding his or her breath in expiration. There could also be a coexistent aortic systolic flow murmur, caused by the large stroke volume (rather than reflecting organic AS). There may be a mid diastolic murmur at the apex (Austin Flint murmur) caused by the regurgitant aortic jet vibrating the anterior mitral valve (MV) leaflet.

Acute aortic regurgitation

Acute AR is one hallmark of aortic dissection and is a medical emergency in its own right. A large regurgitant volume is suddenly imposed on an LV of normal size that has not had time to accommodate to the volume overload. The result is a reduction in stroke volume, compensatory tachycardia, pulmonary edema, and cardiogenic shock. Characteristic clinical findings are absent and an echo is essential to document the severity of the lesion. This is done by assessing the speed of equilibration of aortic and LV pressures in diastole. Useful echo measures are short regurgitant wave half time, short mitral deceleration time, and premature closure of the MV.

Mortality is high in acute severe AR and early surgical intervention is essential. Nitroprusside can be helpful in reducing preload and afterload, possibly in combination with dobutamine or dopamine. Intra-aortic balloon pumping is absolutely contraindicated (it increases aortic diastolic pressure and worsens the regurgitation), while β-blockers, often used in the management of dissection, should be used with caution in associated acute severe AR as they dampen the compensatory tachycardia.

Chronic aortic regurgitation

An early diastolic murmur is always justification for referral to a cardiologist for assessment and echo.

Causes

  • Rheumatic involvement of the aortic valve, resulting in thickening of the cusps and fusion of the commissures – the valve neither opens nor closes completely.
  • Dilatation of the aortic root resulting from aneurysm of the ascending aorta – this is commonly seen in Marfan's syndrome.
  • Dilatation of the aortic annulus can also result from connective tissue disease, such as ankylosing spondylitis, rheumatoid arthritis, Reiter's syndrome, relapsing polychondritis, or systemic lupus erythematosus.
  • Dissecting aneurysm involving the aortic root.
  • Syphilitic aortitis causing aortic aneurysm and dilatation of the valve ring that may involve the coronary ostia.

Table 2 outlines the causes of aortic regurgitation.

Natural history and therapeutic options

Chronic AR represents a condition of combined volume and pressure overload on the LV. The ejection fraction (EF) – the percentage of the end diastolic volume ejected during systole – is maintained by compensatory LVH and the majority of patients remain in this compensated phase for decades. However, in time, the EF drops. Although initially this is fully reversible, soon, due to progressive dilatation and remodeling, full recovery with AVR is out of reach. A large number of studies have identified LV systolic dysfunction and end systolic dimension as the key determinants of survival in patients undergoing AVR for AR. Thus, in contrast to AS, the critical point when the benefit of AVR outweighs the risk is determined not by symptoms, but by echo-determined LV function. More specifically, AVR is indicated in:

  • patients with New York Heart Association (NYHA) class III or IV symptoms (see Chapter 7, Heart failure) and preserved LV systolic function – defined as normal EF (≥50% at rest)
  • patients with NYHA class II symptoms and preserved LV systolic function at rest, but with progressive LV dilatation, declining rest EF, or declining effort tolerance (the trend is more important than the absolute level)
  • patients with angina on walking or climbing stairs rapidly
  • asymptomatic or symptomatic patients with mild to moderate LV dysfunction at rest (EF 25%–49%)
  • patients undergoing open chest surgery for another reason (eg, bypass grafting)

Exercise testing can be useful in AR if the patient is sedentary or has equivocal symptoms. It assesses functional capacity and the hemodynamic effects of exercise. Radionuclide ventriculography should be used if the echo window is poor. Cardiac catheterization is only required in patients at risk of CAD prior to AVR or where other tests are equivocal.

Asymptomatic patients with no LV dysfunction should be encouraged to participate in all forms of normal daily activity, including exercise (although lifting weights should be avoided).

Vasodilator therapy can, in theory, retard the natural history of chronic AR by reducing the regurgitant volume. However, very few studies have actually examined the effect of this treatment on the long-term outcome. Indications for vasodilator therapy (generally using long-acting nifedipine) are:

  • long-term therapy in patients with severe regurgitation who have symptoms and/or LV dysfunction, when surgery is not recommended
  • long-term therapy in asymptomatic patients with severe regurgitation who have LV dilatation, but normal systolic function
  • long-term therapy in asymptomatic patients with hypertension and any degree of regurgitation
  • long-term therapy in patients with persistent LV systolic dysfunction after AVR (angiotensin-converting enzyme inhibitor)
  • short-term therapy to improve the hemodynamic profile of patients with severe heart failure symptoms and severe LV dysfunction before proceeding with AVR

Asymptomatic patients with mild AR and normal LV systolic function should be seen by a cardiologist annually and undergo echo every 2–3 years. Asymptomatic patients with normal systolic function, but severe AR and significant LV dilatation (end diastolic diameter >6 cm), require more frequent evaluation. These patients should be seen by a cardiologist every 6 months and undergo echo every 6–12 months.

Mitral stenosis

The MV apparatus consists of three components: two leaflets, the fibrous annulus, and the chordae tendineae, which connect the leaflets to the papillary muscles (see Figure 1). The anterior leaflet is larger than the posterior leaflet (see Figure 2). The normal area of the MV orifice is 4–5 cm2. Symptoms of mitral stenosis (MS) develop when the orifice is <2.5 cm2 and a critical stenosis occurs when it is approximately 1 cm2 (see Figure 3). The signs and causes of MS are outlined in Table 3.

Figure 1. The structure of the mitral valve apparatus.

Figure 1

The structure of the mitral valve apparatus.

Figure 2. A calcified mitral valve posterior leaflet in diastole.

Figure 2

A calcified mitral valve posterior leaflet in diastole.

Figure 3. Mitral stenosis with left atrial dilatation.

Figure 3

Mitral stenosis with left atrial dilatation. This figure shows a thickened mital valve arrow. The spontaneous contrast is a good illustration of the thrombogenicity of the blood in the left atrium. This is believed to be the first step before the formation (more...)

Table 3. Common murmurs in mitral stenosis and mitral regurgitation with their associated signs and causes.

Table 3

Common murmurs in mitral stenosis and mitral regurgitation with their associated signs and causes.

Causes

Rheumatic heart disease is the most common cause of MS, although it pre-dates the symptoms by at least 10 years. Other acquired causes are rare – eg, annular calcification, endocarditis, or granulomatous infiltration in association with eosinophilia.

Signs

Symptoms of MS generally occur during exertion, infection, stress, or with the onset of atrial fibrillation (AF) with a rapid ventricular response. This is because a left atrial (LA) pressure that is normal at rest rises with an increase in transmitral flow or a decrease in the diastolic filling time.

The most common manifestation is breathlessness, but a reduction in exercise tolerance or symptoms of right-sided congestion can also occur. The typical physical signs are described in Table 4. Figure 4 demonstrates MS in echo, electrocardiography pressure tracing, and a chest x-ray.

Table 4. The typical physical signs of mitral stenosis.

Table 4

The typical physical signs of mitral stenosis.

Figure 4. Mitral stenosis demonstrated by (a) echocardiography (showing thickened leaflets that no longer open), (b) electrocardiography pressure tracing in the left atrium versus left ventricle demonstrating the gradient between the two cavities (and therefore mitral stenosis), and (c) chest x-ray.

Figure 4

Mitral stenosis demonstrated by (a) echocardiography (showing thickened leaflets that no longer open), (b) electrocardiography pressure tracing in the left atrium versus left ventricle demonstrating the gradient between the two cavities (and therefore (more...)

Natural history

The disease takes a slow course with progressive acceleration later in life. In developed countries, the lag period from the time of rheumatic fever to the onset of symptoms is 20–40 years, and there is another 10 years before these symptoms become disabling. The 10-year survival rate is high for asymptomatic patients (>80%), but low for those with symptoms (0%–15%). Asymptomatic patients with mild MS (MV area >1.5 cm2) require no further evaluation and do not need to be followed up more than annually.

Percutaneous and surgical therapy

Decisions on therapy are made by joint consideration of symptoms and MV morphology (including hemodynamics and pulmonary artery pressure). Therapeutic options include MV repair (open/closed commissurotomy), MV replacement, and percutaneous valvotomy.

Both repair and percutaneous valvotomy acutely result in a doubling of the valve area and a 60% reduction in transmitral gradient. However, open commissurotomy and percutaneous valvotomy produce better long-term hemodynamic results. The current recommendations for percutaneous and surgical therapy are outlined in Table 5.

Table 5. Current recommendations for surgical therapy.

Table 5

Current recommendations for surgical therapy.

Medical therapy

Prophylaxis against rheumatic fever and endocarditis should be considered for all patients with MS. Agents with negative chronotropic properties, such as β-blockers or calcium-channel blockers, may benefit those in sinus rhythm with symptoms relating to exertional tachycardia.

Atrial fibrillation

AF develops in 40% of patients with symptomatic MS and should be treated according to standard protocols (see Chapter 8, Arrhythmia). The value of anticoagulation therapy for those with AF and those with a prior embolic event with or without AF is clear. However, there is no evidence that oral anticoagulation is beneficial in those with MS who have neither AF nor a prior embolic event. The frequency of embolic events does not seem to be related to the severity of MS, the size of the LA, or the presence of symptoms. There is some controversy over whether percutaneous mitral valvotomy should be performed in patients with new-onset AF and moderate or severe MS who are otherwise asymptomatic.

Mitral regurgitation

Acute mitral regurgitation

In acute severe mitral regurgitation (MR), the hemodynamic changes are not tolerated and the result is generally acute decompensation. Without time for compensatory LV and LA dilatation, the increase in ventricular preload leads to a decreased stroke volume and pulmonary congestion. However, examination findings may not be typical:

  • there may be no hyperdynamic apex beat
  • the systolic murmur may be short
  • there may be a fourth heart sound

The most common cause of acute MR is papillary muscle rupture secondary to myocardial infarction (MI) (see Figure 5). In this situation, the principal differential diagnosis is ventricular septal defect and an echo is required to differentiate between the two. Ventricular septal defect is more likely with:

Figure 5. (a) Transesophageal echocardiography showing a tear in the papillary muscle (the most common cause of acute mitral regurgitation).

Figure 5

(a) Transesophageal echocardiography showing a tear in the papillary muscle (the most common cause of acute mitral regurgitation). (b) The same scene with a color jet from the left ventricle into the left atrium, demonstrating "blood flow" in the wrong (more...)

  • right-sided radiation of murmur
  • raised jugular venous pressure (JVP)
  • anterior MI (inferior MI is more likely to cause acute MR)

The goal of medical therapy in acute severe MR is to diminish regurgitation, increase stroke volume, and reduce pulmonary congestion. As such, nitroprusside alone or in combination with dobutamine (if blood pressure is low) can be effective. Intra-aortic balloon pumping can also help to achieve these goals. In many cases, emergency surgery is warranted. If so, prior transesophageal echo helps to characterize the anatomy and severity of the lesion. Cardiac catheterization should be performed if the patient is at high risk for CAD.

Chronic mitral regurgitation

Causes

  • Degenerative MV disease is common in the elderly. The valve leaflets are thickened, redundant, increased in area, and they prolapse into the LA in systole. The chordae may become elongated, thinned, and tortuous – predisposing to rupture.
  • Infective endocarditis is a major cause of chronic MR. Vegetations developing on the cusp vary from small nodules along the line of apposition to large friable masses of up to 10 mm or more (see Figure 6). "Jet" lesions on the anterior cusp of the MV can also occur in association with aortic valve endocarditis.
  • Ischemia.

Figure 6. Echocardiogram showing a vegetation on the mitral valve (arrow).

Figure 6

Echocardiogram showing a vegetation on the mitral valve (arrow).

Clinical signs

The clinical signs of chronic MR are outlined in Table 6. With severe MR, the regurgitant murmur is usually short and stops at the same time as aortic valve closure. Occasionally, the murmur can hardly be heard due to early equalization of atrioventricular pressures. The signs and causes of MR are outlined in Table 3.

Table 6. The clinical signs of chronic mitral regurgitation.

Table 6

The clinical signs of chronic mitral regurgitation.

Natural history

In chronic MR, the increased preload and decreased afterload of the LV (caused by ejection of some of the stroke volume into the LA) are compensated for by LV and LA dilatation, and the total stroke volume is increased (the EF is also maintained). This compensated phase of chronic MR may last for years. Eventually, however, the volume overload causes sufficient dilatation to push the LV onto the downward portion of the Frank–Starling curve and dysfunction results (see Figure 7). Importantly, the loading conditions mean that this dysfunction might not be reflected in an abnormal EF (the EF in a patient with MR and normal LV function is >60%).

Figure 7. Frank–Starling curve showing left ventricular (LV) dysfunction.

Figure 7

Frank–Starling curve showing left ventricular (LV) dysfunction.

Asymptomatic patients with mild MR and no evidence of LV dilatation or dysfunction can be followed on a yearly basis and undergo echo less frequently than that. Asymptomatic patients with moderate MR should have an echo annually. Asymptomatic patients with severe MR should be followed up every 6–12 months and undergo echo to detect silent LV dysfunction. Exercise testing is useful to document changes in exercise tolerance.

The timing of surgery is determined by the EF, LV end systolic dimension (LVESD), the presence of AF, and symptoms. It is indicated for those with:

  • class II–IV symptoms, EF >60%, LVESD <45 mm
  • EF 30%–60%, LVESD 45–55 mm (regardless of symptoms)
  • asymptomatic patients with AF and normal EF
  • symptomatic patients with normal EF and pulmonary hypertension (>50 mm Hg)
  • asymptomatic patients with EF 50%–60% and LVESD <45 mm, or EF >60% and LVESD 45–55 mm
  • patients with EF <30% and/or LVESD >55 mm in whom the chordae tendineae are likely to be intact (ie, no previous MI in that territory)

The operation of choice is MV repair. In many patients, however, replacement of the valve together with removal of part or all of the MV apparatus (chordae) is required. The repair procedure leads to better postoperative LV function and survival.

There is no generally accepted medical therapy for chronic MR. Although vasodilators might seem a sensible choice, in fact, in compensated chronic MR the afterload is decreased (since the LV has two routes of ejection); as such, drugs that reduce the afterload further are unlikely to be beneficial.

Chronic MR can also occur due to a primary ischemic cause, relating either to LV dysfunction or to chordal ischemia – revascularization or stenting can eliminate the episodes.

Functional mitral regurgitation

The normal function of the MV depends on the cusps, ring, and subvalvular apparatus, including papillary muscle fibers and the circumferential muscle layer supporting the mitral ring. Each of these components plays a significant role in maintaining the competence of the valve. With papillary muscle dysfunction due to ischemia or other causes of ventricular disease, cusp closure is not complete, leading to some degree of regurgitation. This can even occur, for example, in athletic hypertrophy. This is usually mild, but can be significant in rare cases. In such conditions, the heart rate is usually fast and the duration of MR long enough to compromise filling time and hence cardiac output. Although functional in origin, it can be hemodynamically significant.

Alfred de Musset

"La bouche garde le silence, Pour écouter parler le coeur."a

Alfred de Musset (1810–1857), La Nuit de Mai

The French romantic poet and playwright, Alfred de Musset (1810–1857), was famous for both his creative brain and his pathological heart. His most inspiring work was prompted by the ending of a love affair he had with George Sand (a French romantic writer who later had a 10-year relationship with Chopin). During a visit to Venice in 1834, both Sand and he became very unwell. Such was the quality of care and attention lavished on them by their physician that Sand fell in love with this man and de Musset returned to France alone (where he penned some of his best work). He spent the last 2 years of his life housebound, his heart broken by the combined effects of lost love, aortic regurgitation, and alcohol-related cardiomyopathy. The nodding of his head in time with his heartbeat, the classic eponymous sign of aortic regurgitation, was described by his brother in a biography. When told of it, de Musset apparently placed his thumb and forefinger on his neck and his head stopped bobbing.

aThe mouth keeps silent to hear the heart speak.

Mitral valve prolapse

MV prolapse (MVP) is the single most common valvular abnormality. It affects 2%–6% of the population and is defined as a backward movement of one or both leaflets of the MV (usually the anterior) into the LA during (ventricular) systole. In most cases it is associated with trivial MR. However, as a result of its prevalence, it is also the most common single cause of significant MR. Although MVP does not alter life expectancy, all of the above complications of MR can occur. Sudden death, often reported as an association with MVP, is rare (<2% on long-term follow-up).

Classic findings on auscultation are a mid systolic click followed by a late systolic murmur. The click is thought to be caused by a tensing of the MV apparatus as the leaflets prolapse into the LA. The murmur is usually high pitched and loudest at the apex. Certain maneuvers can help to secure the diagnosis: standing reduces end diastolic volume (EDV), bringing the click–murmur nearer to the first heart sound; squatting increases EDV (and afterload), moving the click–murmur nearer to the second heart sound.

Patients with these findings should be referred for echo assessment. Interestingly, there is no absolute consensus on criteria for diagnosing MVP on two-dimensional echo. The diagnosis should never be made on one view alone (especially if that is the 4-chamber view). Serial echos are not necessary unless there is a change in the clinical picture.

Management involves reassurance and prophylaxis for endocarditis. Patients who suffer from palpitations should have Holter/event monitoring to make a firm diagnosis. Aspirin is recommended for patients with documented focal neurological events who are in sinus rhythm and have no atrial thrombus. Recurrent transient ischemic attacks or stroke in MVP patients demand long-term warfarin therapy. Ultimately, MV repair may be required, and the indications are as for MR (described above).

Tricuspid valve disease

In comparison with the left side, the right side of the heart is a low-pressure system. Consequently, disorders such as endocarditis, in which high-pressure jets help to "seed" the infective vegetations, occur less frequently. The notable exception is in intravenous drug abusers, where right-sided endocarditis is more common. Perhaps the most common cause of tricuspid valve incompetence, however, is elevated right ventricular (RV) pressure, secondary to pulmonary hypertension, MS, pulmonary stenosis, dilated cardiomyopathy, or RV failure. In addition, rheumatic heart disease can affect the tricuspid valve and tends to produce a combination of tricuspid stenosis and regurgitation – the overriding symptoms are those of regurgitation. Ebstein's anomaly is a congenital disorder affecting the tricuspid valve (see Chapter 14, Adult congenital heart disease).

Clinical signs

Physical examination is key to the diagnosis of tricuspid regurgitation. Typical signs are:

  • gross fluid retention
  • significant peripheral edema
  • ascites that may result in nausea
  • raised JVP with a prominent systolic wave and sharp Y descent
  • parasternal heave and loud P2, suggesting pulmonary hypertension as a cause
  • an enlarged, tender, pulsatile liver and, occasionally, mild jaundice
  • a pansystolic murmur at the left lower sternal edge that is increased by inspiration

Management

Severe tricuspid regurgitation resulting from any cause is associated with a poor long-term outcome due to RV dysfunction and systemic venous congestion. The timing of surgery and the most suitable operation remain controversial, although chordal reconstruction and annuloplasty have become established in recent years. Annuloplasty involves the use of a prosthetic ring to support the endogenous dilated annulus. Valve replacement is also possible.

Medical management treats fluid retention and AF. Standard protocols are used, although high doses and combination diuretics are often required.

Pulmonary valve disease

Pulmonary regurgitation is caused by pulmonary hypertension and annular dilatation resulting from various causes of left-sided heart disease (as well as primary pulmonary hypertension). An early diastolic murmur (Graham Steell murmur) is heard over the pulmonary area and should be distinguished from that of AR.

Antibiotic prophylaxis is only required if the cause is rheumatic. Most pulmonary valve disease does not need treatment. However, valve replacement can be carried out in cases of intractable right heart failure.

Valve disease in pregnancy

In pregnancy, there is a 50% increase in circulating blood volume. The cardiac output peaks between the second and third trimesters, predominantly due to an increase in stroke volume, although the heart rate also increases by up to 20%. Total peripheral resistance falls disproportionately, reducing the diastolic blood pressure and widening the pulse pressure. Occasionally, in the supine position the inferior vena cava can be compressed by a gravid uterus, leading to an abrupt decrease in venous return. This can result in light headedness, but quickly resolves on changing position. The increased blood volume and cardiac output can accentuate stenotic murmurs, while the lowered peripheral resistance can actually reduce regurgitant murmurs. In general, echo demonstrates a degree of "physiological" chamber enlargement that, in a significant minority of women, may be associated with functional MR.

In some conditions (eg, cyanotic heart disease, Eisenmenger syndrome, and severe pulmonary hypertension), the changes resulting from pregnancy greatly increase risk and most cardiologists would counsel against pregnancy. The following are also associated with increased risk, either to the mother or fetus:

  • severe AS
  • MR/AR with class III–IV symptoms
  • MS with class II–IV symptoms
  • pulmonary pressures >75% of systemic
  • EF <40%
  • mechanical prosthetic valves requiring anticoagulation
  • AR in Marfan's syndrome

Although risk is increased, many patients with valvular abnormalities can be managed through pregnancy with conservative medical measures aimed at optimizing intravascular volume.

Mitral stenosis

Penicillin prophylaxis should be continued in pregnant women with MS. The cautious use of diuretics and β-blockers in those with mild to moderate disease can prevent tachycardia and optimize diastolic filling. For women with severe disease, a percutaneous balloon valvotomy prior to conception should be considered. Those who develop class III–IV symptoms during pregnancy should also undergo valvotomy. This can be achieved with very limited fluoroscopy or appropriate shielding.

Mitral regurgitation

The usual cause of MR is MVP; this rarely requires treatment.

Aortic stenosis

The most likely cause of AS in a woman of childbearing age is congenital bicuspid disease. Mild to moderate obstruction can be managed conservatively throughout pregnancy, whereas those with severe disease (eg, gradient >50 mm Hg, LV function likely to be normal) should be advised to delay conception until treatment is obtained.

Aortic regurgitation

AR can usually be managed medically with a combination of diuretics and vasodilator therapy. As with MR, surgery should be contemplated during pregnancy for the control of class III–IV symptoms.

Anticoagulation in pregnancy

Warfarin crosses the placenta and has been associated with an increased incidence of spontaneous abortion, fetal deformity, prematurity, and stillbirth. The incidence is probably around 5%–10%. In contrast, heparin does not cross the placenta and is generally safer. However, it is associated with a higher degree of thromboembolic complications. The evidence base for decision making is not good, and the decision should be made in partnership with the patient after explaining the risks involved. Most change from warfarin to heparin at week 36 in anticipation of labor.

Further reading

  1. Guidelines for the management of patients with valvular heart disease. Executive summary: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Committee on Management of Patients with Valvular Heart Disease) Circulation. 1998;98:1949–84. [PubMed: 9799219]
  2. Phoon CK. Estimation of pressure gradients by auscultations: an innovative and accurate physical examination technique. Am Heart J. 2001;141:500–6. [PubMed: 11231450]
  3. Shry EA, Smithers MA, Mascette AM. Auscultation versus echocardiography in a healthy population with precordial murmur. Am J Cardiol. 2001;87:1428–30. [PubMed: 11397373]
Copyright © 2004, Remedica.
Bookshelf ID: NBK2220

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