Tricuspid valve

The tricuspid valve is on the right side of the heart, between the right atrium and the right ventricle. The normal tricuspid valve usually has three leaflets and three papillary muscles. Tricuspid valves may also occur with two or four leaflets, and the number may change during life (Van Pragh, 1998).

Valves

 * The largest cusp is interposed between the atrioventricular orifice and the conus arteriosus and is termed the anterior or infundibular cusp.
 * A second, the posterior or marginal cusp, is in relation to the right margin of the ventricle.
 * A third, the medial or septal cusp, to the ventricular septum.
 * The tricuspid valve prevents the blood from returning to the right atrium when the right ventricle contracts

Pathology
A small amount of leakage or regurgitation is not uncommon in the tricuspid valve. It is a common valve to be infected (endocarditis) in IV drug users. Although it is not a common site of endocarditis, patients with a small VSD usually develop endocarditis of the tricuspid valve.

The tricuspid valve can be affected by rheumatic fever which can cause tricuspid stenosis or tricuspid insufficiency (also called tricuspid regurgitation).

Some patients are born with congenital abnormalities of the tricuspid valve. Congenital apical displacement of the tricuspid valve is called Ebstein's anomaly and typically causes significant tricuspid regurgitation.

The first endovascular tricuspid valve implant was performed by physicians at the Cleveland Clinic.

Images
Images shown below are Courtesy of Professor Peter Anderson DVM PhD and Published with permission. © PEIR, University of Alabama at Birmingham, Department of Pathology

Additional reading

 * Richard Van Pragh: Cardiac anatomy in A. C. Chang et al.: Pediatric Cardiac Intensive Care, Philadelphia 1998.
 * Moss and Adams' Heart Disease in Infants, Children, and Adolescents Hugh D. Allen, Arthur J. Moss, David J. Driscoll, Forrest H. Adams, Timothy F. Feltes, Robert E. Shaddy, 2007 ISBN 0781786843