[An operative case of aortic regurgitation due to quadricuspid valve].

A case of quadricuspid aortic valve is described. A 43-year-old man admitted because of chest oppression on exercise. He had a ejection systolic murmur and decrescendo diastolic murmur. Electrocardiogram revealed severe left ventricular hypertrophy. Echocardiogram showed dilated left ventricle and supernumerary cusp between the right and left coronary cusp. Aortogram revealed quadricuspid aortic valve with grade 4 aortic regurgitation. At operation, quadricuspid aortic valve in which supernumerary cusp between right and left coronary cusp was smaller was found. Four cusps were excised and replaced with 23 mm Medronic-Hall prosthesis. His postoperative course was uneventful. Quadricuspid aortic valve has been extremely rare. Twenty operative cases has been reported. The clinical feature was presented.