Thrombosis in coronary vasculature is a fundamental factor in the mortality of ischemic heart disease. Coronary thrombosis almost invariably occurs in an atherosclerotic artery, but what new changes occur as a prelude to thrombotic accident in an artery diseased for many years? Does an intramural hemorrhage usually initiate the thrombotic process? A small number of investigators have attempted to answer these questions by study of the thrombosed coronary artery by serial-section technique, but there has been no agreement regarding conclusions. Recently Friedman and Van den Bovenkamp1 submitted 40 intact thrombosed coronary artery segments to serial section and various histochemical procedures. Results of this study indicate that fracture of the lumen wall and communication between lumen and atheromatous abscess preceded and was responsible for 39 of their 40 cases of coronary thromboses.
A number of observations suggested the sequence of thrombosis cited. The majority of thrombi contained elements of atheromatous