Tricuspid regurgitation (tricuspid incompetence, tricuspid insufficiency) is leakage of blood backward through the tricuspid valve each time the right ventricle contracts.
As the right ventricle contracts to pump blood forward to the lungs, some blood leaks backward into the right atrium, increasing the volume of blood there and resulting in less blood being pumped through the heart and to the body. As a result, the right atrium enlarges, and blood pressure increases in the right atrium and the large veins that enter it from the body. The liver may swell because of this increased pressure. Enlargement of the right atrium also can result in atrial fibrillation, a rapid, irregular heartbeat. Eventually, heart failure develops.
Tricuspid regurgitation usually results when the right ventricle enlarges and resistance to blood flow from the right ventricle to the lungs is increased. Resistance may be increased by a severe, long-standing lung disorder, such as emphysema or pulmonary hypertension, by disorders involving the left side of the heart, or rarely by narrowing of the pulmonary valve (pulmonic stenosis). To compensate, the right ventricle enlarges, stretching the tricuspid valve and causing regurgitation.
Other, less common causes are infection of the heart valves (infective endocarditis most often due to intravenous injection of illicit drugs), use of fenfluramine (no longer available), birth defects of the tricuspid valve, injury, rheumatic fever and hereditary weakness of the mitral valve tissue (myxomatous degeneration).
Symptoms and Diagnosis
Tricuspid regurgitation can cause vague symptoms, such as weakness and fatigue. They develop because the heart is pumping a smaller amount of blood. Usually, the only other symptoms are pulsations in the neck from the elevated right atrial pressure and discomfort in the right upper part of the abdomen due to an enlarged liver. Heart failure results in accumulation of fluid in the body, mainly in the legs.
The diagnosis is based on the person's medical history and results of a physical examination, electrocardiography (ECG), and chest x-ray. Through a stethoscope, doctors may hear a characteristic murmur produced by the blood leaking backward through the tricuspid valve, but the murmur tends to disappear as the regurgitation worsens. Echocardiography (see Diagnosis of Heart and Blood Vessel Disorders: Echocardiography and Other Ultrasound Procedures) can produce an image of the leaky valve and show the amount of blood leaking, so that the severity of the regurgitation can be determined.
Usually, mild tricuspid regurgitation requires little or no treatment. However, the underlying disorder, such as emphysema, pulmonary hypertension, pulmonic stenosis, or abnormalities of the left side of the heart, is likely to require treatment. Treatment of atrial fibrillation and heart failure is also necessary, but surgery to repair the tricuspid valve is rarely done unless surgery on another heart valve (for example, mitral valve replacement) is also needed. In such cases, the tricuspid regurgitation is usually due to enlargement of the ring (annulus) supporting the valve leaflets. Surgery involves sewing in a ring to reduce the size of the annulus, thus avoiding the need for a prosthetic valve.
Last full review/revision March 2013 by Guy P. Armstrong