Tricuspid valve

Function

The tricuspid valve guards the right atrioventricular opening with three leaflets — anterior, posterior and septal — anchored by chordae tendineae to three papillary muscles. Its annulus is the largest of the four cardiac valves, spanning about 4 cm.

During ventricular filling it swings open passively with the pressure gradient, then slams shut as systole begins — contributing the second, softer component of the first heart sound (S1), just after mitral closure. Its auscultation area in the fourth/fifth intercostal space at the lower-left sternal edge is where auscultation of right-sided murmurs begins.

Blood supply

Right coronary artery branches.

Nerve supply

No direct motor innervation — closure is purely hydraulic.

Clinical relevance

Tricuspid regurgitation

Leakage in systole sends blood back to the atrium, producing giant v-waves in the neck veins and a pulsatile liver.

Endocarditis of right heart

Intravenous drug users seed this valve; tricuspid vegetations shower septic pulmonary emboli.

Related conditions

• Infective endocarditis