Tricuspid regurgitation is a disorder involving backward flow of blood across the tricuspid valve which separates the right ventricle (lower heart chamber) from the right atrium (upper heart chamber).

This occurs during contraction of the right ventricle and is caused by damage to the tricuspid heart valve or enlargement of the right ventricle.

The most common cause of tricuspid regurgitation is not damage to the valve itself, but enlargement of the right ventricle, which may be a complication of any disorder that causes failure of the right ventricle.

Other diseases can directly affect the tricuspid valve. The most common of these is rheumatic fever, which is a complication of untreated strep throat infections. The valve fails to close properly, and blood can flow back to the right atrium from the right ventricle, and from there back into the veins. This reduces the flow of blood forward into the lungs. The condition affects about 4 out of 100,000 people.

Another important risk factor for tricuspid regurgitation is use of the diet medications called "Phen- fen" (phentermine and fenfluramine) or dexfenfluramine.

Rarely tricuspid regurgitation can be caused by an unusual tumor called carcinoid. This tumor secretes a hormone which damages the valve.

In the absence of high blood pressure in the lungs (pulmonary hypertension), tricuspid regurgitation is usually asymptomatic. If pulmonary hypertension and moderate-to-severe tricuspid regurgitation coexist, symptoms may include:

• active neck vein pulsations
• swelling of the abdomen
• swelling of the feet and ankles
• fatigue, tiredness
• weakness
• decreased urine output
• generalized swelling

When gently pressing with the hand (palpation) on the chest, there may be a lift produced by the beating of the enlarged right ventricle. Similarly, there may be a pulsation over the liver. The liver and spleen may be enlarged.

Listening to the heart with a stethoscope shows a murmur or abnormal sounds. Ascites (collection of fluid in the abdomen associated with liver disorders) may be present.

Enlargement of the right side of the heart may show on an ECG or echocardiogram.

Pressures inside the heart and lung may need to be measured with Doppler echocardiography or right-sided cardiac catheterization.

• worsening of heart failure
• endocarditis (heart valve infection)
• cirrhosis
• weight loss, loss of appetite

Discuss any history of heart valve disease or any family history of congenital heart diseases before treatment by a health care provider or dentist. Any dental work, including cleaning, and any invasive procedure can introduce bacteria into the bloodstream. This bacteria can infect a weakened valve causing endocarditis.

Obtain prompt treatment for conditions that may cause valve disease. Treat strep infections promptly to prevent rheumatic fever.