A rare cause of severe aortic regurgitation: quadricuspid aortic valve.

Quadricuspid aortic valve (QAV) is a rare cause of valve failure. Often, it is an incidental finding at transesophageal echo (TEE), surgery or post-mortem examination. This anomaly is often associated with abnormally placed left coronary ostium that could be damaged during the operation. We report a case of QAV detected incidentally during perioperative TEE.