Tricuspid Valve Disease

The majority of serious heart valve problems affect the mitral and aortic valves, disease of the tricuspid and pulmonary valves are fairly rare but are more common in India, Pakistan, and other developing countries than in North America or Western Europe:

• Tricuspid regurgitation is more common than tricuspid stenosis and usually develops in association with pulmonary hypertension in patients with mitral stenosis or mitral regurgitation.
• Tricuspid regurgitation may occur as a result of trauma or infective endocarditis.
• Tricuspid stenosis is nearly always rheumatic in origin. However a similar clinical presentation may occur with:
  • Congenital tricuspid atresia
  • Tumours in the right atrium
  • Obstruction of right ventricular inflow due to endomyocardial fibrosis in carcinoid syndrome
  • Tricuspid valve vegetations
  • Presence of a pacemaker lead
  • Compression due to extracardiac tumours

• Valve leaflets become thickened and undergo sclerosis with narrowing of the opening area of the valve.
• This leads to enlargement of the right atrium, and reduced flow into the ventricle. Blood flow into the pulmonary circulation is impaired, and is accompanied by peripheral oedema and hepatomegaly.
• Chronic rheumatic heart disease is usually the underlying cause and tricuspid stenosis is almost invariably associated with mitral valve disease.¹
• Other causes include carcinoid syndrome, systemic lupus erythematosus, right atrial myxoma, congenital atresia or infiltrating tumours.

Presentation

• History of rheumatic fever.
• Low output symptoms of fatigue, anorexia, wasting, peripheral cyanosis and cold skin.
• Usually those of accompanying left-sided rheumatic valve lesions.
• Right hypochondrial discomfort from liver distension, hepatic pulsation, ascites and peripheral oedema, which are severe compared to degree of dyspnoea.
• In sinus rhythm - an 'a' wave in the jugular venous pulse.
• A low rumbling diastolic murmur along the left sternal border which increases with inspiration.
• Tricuspid regurgitation is often also present, causing a pansystolic murmur in a similar location.
• The first heart sound may be split widely and the second heart sound may be single (inaudible closure of the pulmonary valve).

Investigations

• ECG may show evidence of right atrial hypertrophy with tall peaked P waves; arrhythmias (e.g. atrial fibrillation, atrial flutter) occur frequently.
• Chest x-ray may show dilated right atrium without an enlarged pulmonary-artery segment.
• Echocardiography; detect and quantitate tricuspid stenosis, assessment of the dimensions of cardiac chambers, determination of right ventricular and pulmonary pressures, and detection of associated other heart valve abnormalities.²
• Cardiac catheterisation; may be required prior to surgery to assess for possible coronary artery disease. Right heart catheterisation can help determine the severity of the stenosis and determine associated congenital defects. Assessment of aortic and mitral valves via left heart catheterisation is useful in patients with rheumatic disease.¹

Management

• Treatment of the underlying condition, e.g. antibiotics for endocarditis.
• Treatment of associated arrhythmias.
• Reduction of volume overload with diuretics and salt restriction.
• Surgery:
  • Rarely severe enough to warrant valvotomy, when valve replacement in conjunction with other valves is usually required.
  • Surgery is required if right heart failure or low cardiac output are not adequately controlled by medical treatment. Surgery is usually performed in combination with mitral and/or aortic valve disease repair.
  • For tricuspid valve replacement, the risk of thrombosis is significant and warfarin therapy is advised.
  • Percutaneous balloon valvuloplasty is successful, unless there is significant associated tricuspid regurgitation.

Prognosis

• Prognosis is generally good but dependent on the prognosis of the underlying disease, associated other heart abnormalities and associated arrhythmias.

• Usually due to combination of right ventricular dilation and high pressure (secondary to severe pulmonary hypertension, right ventricular outflow obstruction).
• Other causes include rheumatic heart disease,³ infective endocarditis (e.g. IV drug abuse), papillary muscle dysfunction (right ventricular infarction), following heart transplantation,⁴ carcinoid syndrome and rare congenital causes (including Ebstein's anomaly).
• Iatrogenic causes include latent regurgitation unmasked following mitral valvotomy, and fenfluramine.

Presentation

• Often asymptomatic in the absence of pulmonary hypertension.
• Development of pulmonary hypertension leads to reduction of cardiac output and features of right heart failure with dyspnoea, fatigue, cyanosis, cold skin, oedema and discomfort in right hypochondrium.
• Jugular venous pressure is elevated with a prominent systolic v wave.
• Right ventricular impulse is hyperdynamic and may be thrusting in quality.
• Systolic pulsations of an enlarged, tender liver, ascites and oedema.
• High-pitched pansystolic murmur, most prominent in the fourth intercostal space in the left parasternal region. In the absence of pulmonary hypertension, the murmur is usually of low intensity and early systolic.
• The murmur is accentuated during inspiration, with exercise, with legs raised, and with direct liver compression.
• Pulmonary component of second heart sound becomes louder in presence of pulmonary hypertension.
• Tricuspid valve prolapse may present with a midsystolic click and a late systolic murmur, most prominent at the lower left sternal border.

Investigations

• ECG: findings are usually non-specific; may show right atrial hypertrophy (tall peaked p waves), incomplete right bundle-branch block, Q waves in lead V1, and atrial fibrillation.
• Chest X-ray shows marked cardiomegaly with right heart enlargement, pleural effusions. Ascites with diaphragmatic elevation may be present. Pulmonary arterial and venous hypertension is common.³
• Echocardiography;: detect and quantitate tricuspid regurgitation, assessment of the dimensions of cardiac chambers, determination of right ventricular and pulmonary pressures, and detection of associated other heart valve abnormalities.²
• Cardiac catheterisation: may be required prior to surgery to assess for possible coronary artery disease, and help determine the severity of the regurgitation and determine associated congenital defects.

Management

• Treatment of the underlying condition, e.g. antibiotics for endocarditis.
• Treatment of associated arrhythmias.
• Reduction of volume overload with diuretics and salt restriction.
• Surgery:
  • Surgery is indicated for structural deformity of the valve (e.g. Ebstein anomaly), if the valve has been destroyed by bacterial endocarditis, or when ventricular dilatation is severe and uncontrolled with medical therapy.
  • Tricuspid valve replacement is often required but severe regurgitation has been successfully treated with tricuspid annuloplasty. However for patients with very severe regurgitation, requiring very large doses of diuretics, repair and replacement are unsatisfactory with high risk.⁵
  • Infective endocarditis: total excision of the tricuspid valve without immediate replacement is well tolerated by most patients. Diseased valvular tissue is excised to eradicate the endocarditis. Valve replacement may be necessary if medical management does not control the tricuspid regurgitation and the infection has been controlled.

Prognosis

• Even severe regurgitation may be well tolerated for years.
• If due to heart failure, then medical treatment with diuretics may eliminate functional regurgitation.
• Where tricuspid regurgitation is associated with left sided heart disease this may subside spontaneously after its treatment.
• If the patient has associated pulmonary hypertension or cardiac dilatation, the prognosis is dependent on the prognosis for these problems.³