Thrombosis of the coronary arteries.

"...includes electrocardiographic tracings of a 42-year-old physician who died "after coronary obstructive symptoms" and of a dog following experimental ligation of a coronary artery. This finding "led Herrick to conclude that coronary occlusion might be accompanied by characteristic electrocardiographic changes that would help physicians recognize coronary thrombosis. Thus, Herrick provided clinicians with both an intellectual framework for conceptualizing survival after coronary thrombosis and a new diagnostic approach [electrocardiography] to help them recognize this event" (W. Bruce Fye, "Acute myocardial infaction: A historical summary," 1990).