Obstruction of coronary blood flow and the resultant consequences are the center stage pathophysiologic events in cardiology today. The speculations of Jenner, Burns, Heberdin, McKenzie, Prinzmetal and many others had until now been left to observations of isolated tissue and intact animal experimentation. Only with the advent of Gruentzig's technique, which allowed us to 'work safely inside the coronary arteries' are we able to observe the effects of coronary occlusion in living conscious man. PTCA provides not only a therapeutic modality for non-operatively opening coronary obstructions,...