Section 3. Heart and Blood Vessel Disorders

Chapter 28. Heart Valve Disorders

Topics: Introduction | Mitral Regurgitation | Mitral Valve Prolapse | Mitral Stenosis | Aortic Regurgitation | Aortic Stenosis | Tricuspid Regurgitation | Tricuspid Stenosis | Pulmonary Stenosis

Tricuspid Regurgitation

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. As a result, the right atrium enlarges, and pressure in the veins that enter the right atrium is increased, creating resistance to blood flow from the body to the heart.

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, or by narrowing of the pulmonary valve (pulmonary stenosis). To compensate, the right ventricle enlarges and thickens so that it can pump harder, and the valve opening stretches.

Other, less common causes are infection of the heart valves (infective endocarditis), use of fenfluramine, birth defects of the tricuspid valve, injury, and myxomatous degeneration (a hereditary disorder in which the valve gradually becomes floppy).

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 and discomfort in the right upper part of the abdomen due to an enlarged liver. These symptoms develop because blood flows backward from the heart into the veins. Enlargement of the right atrium can result in a rapid, irregular heartbeat (atrial fibrillation). Eventually, heart failure develops, resulting 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 can hear a characteristic murmur produced by the blood leaking backward through the tricuspid valve. Echocardiography (see Section 3, Chapter 21) can produce an image of the leaky valve and the amount of blood leaking, so that the severity of the regurgitation can be determined.

Treatment

Usually, tricuspid regurgitation requires little or no treatment. However, the underlying disorder, such as emphysema, pulmonary hypertension, or pulmonary stenosis may require treatment. Usually, treatment of the resulting atrial fibrillation and heart failure does not include surgery on the tricuspid valve.