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Scientific establishment of the overall role of coronary artery bypass surgery in the management of patients with coronary disease is probably one of the most pressing issues in medicine in the United States today. It inherently embodies major medical, social, and economic implications. Controversy continues to abound in many areas concerning indications, contraindications, accuracy of diagnosis, mortality, morbidity, importance of patient age, relief of symptoms, improvement in measured physical performance, effect on sudden death, prolongation of longevity, hemodynamic change, amelioration of congestive heart failure, effect on rhythm disturbances, importance of collaterals, graft patency, return of symptoms, myocardial infarction rate, mechanisms of action, and patient rehabilitation potential and cost-effectiveness. Strong stances are taken by experts ranging from the ultraconservative to the ultra-aggressive ends of the spectrum. Working through this maze of conflicts becomes a difficult task for the physician seeking to advise his patients in good conscience. No difficulty lies with

CORONARY artery bypass surgery still generates wide-spread controversy. There are divergent viewpoints among competent cardiologists regarding indications, risks, longterm results, and costs. Similarly, questions still arise concerning morbidity and mortality, risk, identification and importance of perioperative infarction, and long-term fate of the native and bypassed coronary vessels, as well as of the vein graft itself. Futhermore, long-term follow-up studies reaffirm the palliative nature of the procedure for the majority of patients. Amid this continuing controversy of the role of aortocoronary bypass in the treatment of various coronary artery disease syndromes, a new method for the treatment of myocardial ischemia has been introduced: percutaneous transluminal coronary angioplasty (PTCA). The method is particularly attractive because of its simplicity. Introduced by a preformed coronary catheter (similar to the standard catheters used for routine coronary angiography), a balloon-tipped catheter is advanced into the obstructed coronary artery segment, rapidly inflated (under 4 to 6 atm)

Normal mitral valve function is dependent upon several structures other than the valve leaflets alone. These structures are in anatomic continuity from the atrial muscle to the ventricular muscle and, in addition to the leaflets, include the valve ring, the chordae tendineae, conduction tissue, and the papillary muscles. For perfectly normal valve function, each of these structures must be (1) anatomically and functionally intact, (2) in appropriate spatial interrelationship, and (3) operative in correct temporal sequence with respect to related structures. Obviously, normal mitral valve function is dependent upon a rather complex and finely coordinated system. In the past, of all the structures in this system, the papillary muscles have received the least interest and study. Yet they are of paramount importance, and disturbances of their function are a common cause of mitral valve incompetence. Pathophysiology Causes of papillary muscle dysfunction may be outlined as follows: Circulatory insufficiency (ischemia) Angina