tricuspid

The term tricuspid derives from Latin tri- meaning three and cuspis meaning cusp. In medicine, it describes structures with three cusps, most notably the tricuspid valve of the heart.

The tricuspid valve lies between the right atrium and right ventricle and consists of three leaflets or cusps: anterior, posterior, and septal. The leaflets attach to a fibrous annulus and are connected to the right-ventricular papillary muscles by chordae tendineae. During diastole, the valve opens to allow flow from the atrium to the ventricle; during systole, it closes to prevent regurgitation into the atrium.

The valve contributes to unidirectional blood flow and right-heart function, working in concert with the pulmonary, mitral, and aortic valves. Its structure can be altered by dilation of the right ventricle or annulus, rheumatic disease, infective endocarditis, congenital anomalies, or pulmonary hypertension.

Disorders include tricuspid regurgitation, where blood flows backward into the right atrium during systole, and tricuspid stenosis, a narrowing of the orifice. Symptoms range from none to fatigue, edema, ascites, and hepatomegaly in advanced disease. Diagnosis is primarily by echocardiography; other imaging can help. Treatment includes diuretics for symptom relief and, in severe cases, repair or replacement, which can be surgical or transcatheter.

In botany and other contexts, tricuspid also describes three-pointed or three-cusp structures, such as certain leaves or petals, though this sense is less commonly used in clinical texts.