ABSTRACT
A 40-year old man with chest pain was admitted to our hospital. A three-dimensional CT revealed an unruptured left coronary sinus of Valsalva aneurysm and mild stenosis of the left main trunk. An echocardiogram revealed severe aortic regurgitation. He was operated on with an aortic root replacement procedure. Though the procedure was itself uneventful, he could not be weaned from cardiopulmonary bypass because of unexpected coronary events ; relative stenosis of the RCA and stretched LMT due to a huge aneurysm of the sinus of Valsalva. Additional CABG with LITA to LAD and SVG to RCA led to weaning from cardiopulmonary bypass. Left coronary sinus of Valsalva aneurysm is rare, and it requires early surgical intervention for an increase in the diameter of the aneurysm together with myocardial ischemia due to compression of the coronary artery.