The selective injection of contrast media into the right coronary artery of a middle-aged male by Dr F. Mason Sones, Jr, on October 30, 1958 (Figure 1) introduced a new era in cardiovascular medicine that was to revolutionize our understanding and management of the cardiac patient for the remainder of the twentieth century.1,2⇓ As the first reliable in vivo marker for the presence of obstructing coronary lesions, the coronary angiogram not only provided objective evidence to support or refute the clinical diagnosis of angina pectoris but, quite importantly, led to our first studies of the natural history of patients with coronary artery disease (CAD). The purpose of this article is to underscore the crucial role this particular technology played in contributing to the epochal events and discoveries that have characterized the march of progress in the field of cardiology over the past 50 years. Figure 1. Cine frame from the first selective coronary arteriogram taken by F. Mason Sones, MD, on October 30, 1958. Reprinted with permission from J Am Coll Cardiol. 1998;31:89B–96B. Sones’ decision to undertake selective visualization of the coronary artery in his patient undergoing catheterization to evaluate mitral regurgitation was, in some measure, the result of a serendipitous event that occurred in his laboratory 2 days earlier. This has been described in detail elsewhere by Dr Willis Hurst3 and entailed a power injection of 40 to 50 cc of contrast media that was intended to be delivered into the aortic root of a patient with aortic regurgitation. Under 10 kg/cm2 of pressure, the catheter whiplashed into the ostia of the right coronary artery, and an estimated 30cc of 90% Hypaque (Nicomed) was selectively delivered as a bolus into the coronary artery before the injection could be aborted. A former fellow of Sones’, Dr …