Causes

Tricuspid valve regurgitation can be caused by a number of conditions.

Tricuspid valve regurgitation is usually caused by the lower right heart chamber (right ventricle) increasing in size, which can cause the tricuspid valve to stop working properly. Several conditions that affect the right ventricle, such as heart failure; conditions that cause high blood pressure in the arteries in your lungs (pulmonary hypertension); or an abnormal heart muscle condition (cardiomyopathy) also may cause the tricuspid valve to stop working properly.

Tricuspid valve regurgitation can also occur with heart conditions that affect the left side of the heart, such as left-sided heart failure that leads to right-sided heart failure.

Tricuspid valve regurgitation can also be caused by valve problems due to:

• Ebstein's anomaly. In this rare condition, the malformed tricuspid valve sits lower than normal in the right ventricle, and the tricuspid valve's leaflets are abnormally formed. This can lead to blood leaking backward (regurgitating) into the right atrium.

  Tricuspid valve regurgitation in children is usually caused by heart disease present at birth (congenital heart disease). Ebstein's anomaly is the most common congenital heart disease that causes the condition. Tricuspid valve regurgitation in children may often be overlooked and not diagnosed until adulthood.

• Infective endocarditis. The tricuspid valve may be damaged by an infection of the lining of the heart (infective endocarditis) that can involve heart valves.
• Carcinoid syndrome. In this rare condition, tumors that develop in your digestive system and spread to your liver or lymph nodes produce a hormonelike substance that can damage heart valves, most commonly the tricuspid valve and pulmonary valves.
• Implantable device wires (leads). Pacemaker or implantable cardioverter-defibrillator wires can sometimes cause injury to the tricuspid valve during placement or removal of the implantable device.
• Endomyocardial biopsy. In an endomyocardial biopsy, a small amount of heart muscle tissue is removed and tested for signs of inflammation or infection. Valve damage can sometimes occur during this procedure.
• Blunt chest trauma. Experiencing trauma to your chest, such as in a car accident, can lead to tricuspid valve regurgitation.
• Rheumatic fever. Rheumatic fever is a complication of untreated strep throat that can damage heart valves, including the tricuspid valve, leading to tricuspid valve regurgitation later in life.
• Congenital heart defects. Some heart defects present at birth (congenital) may affect the tricuspid valve. Most commonly this is Ebstein's anomaly.
• Marfan syndrome. Marfan syndrome, a genetic disorder of connective tissue present at birth, is occasionally associated with tricuspid valve regurgitation.
• Radiation. Chest radiation may damage the tricuspid valve and cause tricuspid valve regurgitation.

How the heart works

Your heart, the center of your circulatory system, is made up of four chambers. The two upper chambers (atria) receive blood. The two lower chambers (ventricles) pump blood.

Four heart valves open and close to let blood flow in one direction through your heart. The tricuspid valve — which lies between the two chambers on the right side of your heart — consists of three flaps of tissue called leaflets.

The tricuspid valve opens when blood flows from the right atrium to the right ventricle. Then the flaps close to prevent the blood that has just passed into the right ventricle from flowing backward.

In tricuspid valve regurgitation, the tricuspid valve doesn't close tightly. This causes the blood to flow back into the right atrium during each heartbeat.