1. As one of the cause of acute myocardial-ischemia, coronary vasospasm has attracted attention increasingly in clinical cardiology. We developed animal model of coronary vasospasm associated with transient myocardial ischemia by administration of histamine or serotonin in atherosclerotic miniature swine. 2. Early systolic dysfunction as well as subendocardial NADH production of the ischemic region occurred within 10 sec after coronary occlusion, but ST segment started to elevate around 30 sec after occlusion in the isolated rat heart. 3. As the important determinant factors of myocardial infarct size, the preocclusive perfusion area as well as collateral flow area could be measured quantitatively by use of double isotopes autoradiograms, and the close correlation was found between the salvaged area and collateral flow area in dogs. An importance of advancement in basic cardiology and development of new research techniques have been emphasized.