The majority of serious heart valve problems affect the mitral and aortic valves; disease of the tricuspid and pulmonary valves is fairly rare but 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.
  • The presence of a pacemaker lead.
  • Compression due to extracardiac tumours.
• Tricuspid atresia is the third most common form of cyanotic congenital heart disease.¹

Tricuspid stenosis

Tricuspid stenosis is rare, occurring in less than 1% of the population. Tricuspid stenosis is almost always rheumatic in origin and is usually associated with involvement of the mitral and aortic valves.²

• 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.²
• 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 the 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.
• CXR may show dilated right atrium without an enlarged pulmonary-artery segment.
• Echocardiography: to detect and quantify tricuspid stenosis, and for assessment of the dimensions of cardiac chambers, determination of right ventricular and pulmonary pressures, and detection of associated other heart valve abnormalities.³
• Cardiac catheterisation: may be required prior to surgery to assess for possible coronary artery disease. Right heart catheterisation can help to determine the severity of the stenosis and associated congenital defects. Assessment of aortic and mitral valves via left heart catheterisation is useful in patients with rheumatic disease.²

Management²

• Treatment of the underlying condition, e.g. antibiotics for endocarditis.
• Treatment of associated arrhythmias.
• Management of heart failure.
• Surgery:
  • 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 for either mechanical or bioprosthetic valve placement.
  • 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.

Tricuspid regurgitation

• The incidence of tricuspid regurgitation is less than 1%.⁴
• It is usually due to a combination of right ventricular dilation and high pressure (secondary to severe pulmonary hypertension, right ventricular outflow obstruction).
• Other causes include rheumatic heart disease,⁴ infective endocarditis (e.g. intravenous drug abuse), papillary muscle dysfunction (right ventricular infarction), following heart transplantation,⁵ carcinoid syndrome and rare congenital causes (including Ebstein's anomaly).
• Iatrogenic causes include latent regurgitation unmasked following mitral valvotomy, and fenfluramine.

Presentation

• It is 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 the 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.
• Heart sounds and murmurs:
  • 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 low-intensity and early systolic.
  • The murmur is accentuated during inspiration, with exercise, with legs raised, and with direct liver compression.
  • The pulmonary component of the second heart sound becomes louder in the 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 nonspecific; they may show right atrial hypertrophy (tall peaked 'p' waves), incomplete right bundle-branch block, Q waves in lead V1, and atrial fibrillation.
• CXR: shows marked cardiomegaly with right heart enlargement, and pleural effusions. Ascites with diaphragmatic elevation may be present. Pulmonary arterial and venous hypertension are common.⁴
• Echocardiography: to detect and quantify tricuspid regurgitation, and for assessment of the dimensions of cardiac chambers, determination of right ventricular and pulmonary pressures, and detection of other associated heart valve abnormalities.³
• Cardiac catheterisation: may be required prior to surgery to assess for possible coronary artery disease, and help determine the severity of the regurgitation and associated congenital defects.

Management⁴

• Treatment of the underlying condition, e.g. antibiotics for endocarditis.
• Treatment of associated arrhythmias.
• Management of heart failure.
• Surgery:
  • Patients with mild tricuspid regurgitation do not require intervention.
  • Surgery is indicated for structural deformity of the valve (e.g. Ebstein's 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.⁶
  • 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.⁴

Tricuspid atresia

Venous blood returning to the right atrium can only exit via an intra-atrial communication. Other cardiovascular anomalies occur in 15-20% of patients with tricuspid atresia, e.g. transposition of the great vessels or a persistent anomaly of the left superior vena cava.¹

Presentation¹

• Tricuspid atresia is usually detected in infancy with cyanosis, heart failure and growth restriction.
• There is a history of feeding difficulties.
• Bacterial endocarditis and brain abscess are common and may present with headaches, seizures or neurological deficits.
• Finger clubbing is common in infants older than three months.
• Raised jugular venous pressure.
• The left ventricular impulse is prominent because of volume overload. The apical impulse is displaced to the left of the mid-clavicular line.
• The liver may be large and pulsatile.
• There is usually a single first heart sound that may be increased in intensity. The second heart sound may be single or normally split.
• Cardiac murmurs are present in 80% of patients, including:
  • A pansystolic murmur, which may signify blood flow through the ventricular septal defect.
  • Systemic-to-pulmonary arterial collaterals or arterial-to-pulmonary arterial anastomoses surgically created to improve pulmonary blood flow, which may cause a continuous murmur.
  • A murmur indicating mitral regurgitation, which may be present.

Investigations¹

• FBC may show polycythaemia.
• Blood gases may show hypoxaemia and acidosis.
• Chest X-ray: cardiomegaly is usually present, with a prominent right heart border (enlargement of the right atrium). Pulmonary vascular markings are usually diminished (but may be increased when pulmonary flow is not obstructed).
• Other investigations include ECG, echocardiography and cardiac catheterisation.

Management¹

• Infants with obstructed pulmonary blood flow and severe hypoxaemia require urgent prostaglandin E infusions in order to maintain patency of the ductus arteriosus.
• Other nonsurgical management includes oxygen therapy, prevention of bacterial endocarditis and management of heart failure.
• Most patients with tricuspid atresia require some form of surgical treatment during the first year of life. Fontan's operation involves the formation of a right atrial-to-pulmonary artery connection or an extracardiac vena cava-to-pulmonary artery anastomosis using a synthetic graft.

Complications¹

• Paradoxical emboli, stroke, brain abscess.
• Polycythaemia.
• Progressive cardiac dilatation.
• Ventricular dysfunction.
• Mitral valve insufficiency.
• Arrhythmias.

Prognosis¹

The 1-year survival rate after Fontan's operation is 85%; the 5-year survival rate is 78%.

Document references

1. Mancini MC; Tricuspid Atresia, eMedicine, Jul 2008
2. Mancini MC; Tricuspid Stenosis, eMedicine, Jul 2008
3. Shah PM, Raney AA; Tricuspid valve disease. Curr Probl Cardiol. 2008 Feb;33(2):47-84. [abstract]
4. Mancini MC; Tricuspid Regurgitation, eMedicine, Nov 2010
5. Wong RC, Abrahams Z, Hanna M, et al; Tricuspid regurgitation after cardiac transplantation: an old problem revisited. J Heart Lung Transplant. 2008 Mar;27(3):247-52. [abstract]
6. Sugimoto T, Okada M, Yamashita C, et al; Surgical assessment of tricuspid valve replacement for severe tricuspid regurgitation without stenosis. Ann Thorac Cardiovasc Surg. 1999 Oct;5(5):300-3. [abstract]

Acknowledgements