A disorder involving backflow of blood from the right ventricle to the right atrium during contraction of the right ventricle. It 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 right ventricular failure.
Many diseases can affect the tricuspid valve.
The most common of these is rheumatic fever . The valve fails to close properly, and blood can backflow 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 incidence is 4 out of 100,000 people. The liver and spleen may be enlarged.