Introduction Techniques for direct-vision repair of the commoner congenital lesions of the right side of the heart are being standardized, and increasing attention is being directed to the left side of the heart. Utilizing cardiac arrest, the aortic valve may be explored fairly easily, and mitral stenosis and insufficiency are being corrected clinically. Unfortunately, acquired lesions of the aortic valve are difficult to repair adequately, and, in addition, aortic insufficiency presents a special problem in that the heart is difficult to arrest, in the first place, and then difficult to restart, in the second. This is due to poor coronary artery perfusion, resulting from the incompetent aortic valve. Mitral stenosis and insufficiency present a more encouraging picture because in most instances the changes in the valve are more amenable to surgical correction than those of the aortic valve and the problems related to cardiac arrest differ from those associated with