The studies of Blumgart, Schlesinger, and Zoll,1 in reference to the role of coronary occlusion and the collateral circulation in angina pectoris, emphasized that the pain of angina pectoris is a manifestation of myocardial ischemia and that the underlying mechanism seems to be a relative disproportion between the demands of the heart for blood and the supply of blood through the coronary arteries. If the duration of ischemia, as in angina pectoris, is brief, no permanent myocardial damage may occur or only microscopic foci of necrosis and fibrosis may result. It was interesting that they found complete occlusion or narrowing of one or more major coronary arteries and their primary branches in the hearts of a considerable number of persons, which had not given rise to cardiovascular signs or symptoms. They state that complete occlusion of one or more major coronary arteries is compatible with comfort and longevity. Clinical