The tricuspid valve allows blood to flow from the right atrium down into the right ventricle. Tricuspid valve disease is rare, but includes tricuspid valve regurgitation, tricuspid valve stenosis, and Ebstein anomaly. The tricuspid valve can also be injured during closed chest trauma (e.g., a leaflet tear or papillary muscle head avulsion). Like other forms of heart valve disease, tricuspid disease is graded and can range from mild to severe. The tricuspid valve has been called the “Cinderella” of the four heart valves because it is often ignored, even when it is diseased. Untreated heart valve disease can lead to congestive heart failure, cardiomyopathy, stroke, arrhythmia, or blood clots.
Tricuspid Valve Regurgitation
Tricuspid valve regurgitation, also called tricuspid insufficiency or tricuspid incompetence, is an abnormality that occurs when the valve does not close properly, allowing blood to leak backward into the right atrium. In time, it causes pressure to build up in the right atrium and blood to back up into the major veins. Tricuspid regurgitation can be caused by infective endocarditis, fungal infection, rheumatic fever, an enlarged right ventricle, or right ventricular failure due to increased pressure in the pulmonary artery. It also may be associated with Ebstein anomaly, carcinoid tumors, Marfan syndrome, traumatic injury, rheumatoid arthritis, radiation therapy, and the diet drugs “Fen-Phen.” Patients with tricuspid regurgitation may be asymptomatic; but those with associated pulmonary hypertension may experience generalized swelling (especially in the abdomen, feet, and ankles), neck vein pulsing, fatigue, weakness, decreased urine output, and liver problems.
Tricuspid Valve Stenosis
Tricuspid valve stenosis (or obstruction) is a narrowing or blockage of the tricuspid valve. The narrowing occurs when the leaflets change shape or fuse together from an infection (rheumatic fever), a congenital heart defect, calcium deposits, or scar tissue. The narrowing decreases blood flow through the valve, allowing blood to backup in the right atrium and, eventually, the major veins. Severe tricuspid valve obstruction may lead to the enlargement of the right atrium, heart failure, stroke, arrhythmias, or blood clots. Tricuspid valve stenosis is usually acquired (not congenital), and is most often associated with rheumatic fever and concomitant mitral valve stenosis. Most patients are asymptomatic, but those who do experience symptoms complain of fatigue and/or liver pain.
Ebstein anomaly is a congenital malformation of the tricuspid valve where one or two of the valve’s leaflets are adhered or stuck to the heart wall. An atrial septal defect may also be present. It is a cause of tricuspid valve regurgitation. If the regurgitation is severe enough, or if it causes a pathological arrhythmia, the valve may need to be repaired or replaced.
Diagnosis of Tricuspid Valve Disease
Heart valve disease is diagnosed by listening to the heart with a stethoscope; diseased heart valves make distinct clicking sounds or murmurs. Other diagnostic tests that are used to determine the underlying cause, complexity, and severity of heart valve disease include a chest x-ray, blood tests, an echocardiogram (transthoracic or transesophageal), electrocardiography (ECG) or Holter monitoring, exercise stress testing, electrophysiology (EP) studies, cardiac catheterization, and diagnostic imaging scans, such as computed tomography (CT), magnetic resonance imaging (MRI), or positron emission tomography (PET). A careful and complete diagnostic workup will help determine the timing and composition of the treatment plan.
Treatment of Tricuspid Valve Disease
Medications may be used to treat the symptoms, but they cannot cure heart valve disease. Severe tricuspid stenosis is life-threatening, and when this occurs, the valve must be opened. This procedure, called a valvotomy, does not repair the valve; it only relieves the stenosis. It can be performed in either the cardiac catheterization laboratory or in the operating room. Tricuspid valve leakage is likely to develop after a valvotomy procedure, and if it does, the valve will eventually need to be replaced.
Most cardiovascular surgeons agree that valve repair is the preferred method of treatment. Surgically separating or shaving back valve leaflets (a commissurotomy) can eliminate tricuspid stenosis and improve blood flow. Recent studies have shown that defective tricuspid valves that are left unrepaired during mitral valve surgery may worsen to the point that another surgery is later required.
If the lesion is too severe to be repaired, the valve must be replaced. Replacement involves removing the defective valve and replacing it with a prosthetic valve. Prosthetic valves can be biological (made from human or animal tissue) or mechanical (made from materials such as plastic, carbon, or metal). Mechanical valves carry the risk of forming a blood clot on the new valve, so patients with mechanical heart valves must take blood-thinning medicine for the rest of their lives to prevent this complication.
Preventative Antibiotics and Heart Valve Disease
Patients with heart valve disease who have an abnormal heart or who have had heart surgery risk developing endocarditis. The American Heart Association no longer recommends taking routine antibiotics before certain dental or surgical procedures except for people at the highest risk for bad outcomes if they do develop endocarditis.
Texas Heart Institute www.texasheartinstitute.com/HIC/Topics/Cond/vtricus.cfm
Medline Plus www.nlm.nih.gov/medlineplus/ency/article/000169.htm