Dipyridamole induced directory disfunction of infarcted vessel, and estimation of patients with acute myocardial infarction and successful PTCA

The purpose of this study was to determine whether transient disturbance of vascular dilation in the peripheral coronary vessels in patients with myocardial infarction in whom coronary recanalization was successfully attained in the acute stage. The subjects were 6 patients with acute myocardial infarction in whom recanalization was successfully attained without a significant coronary stenosis by emergency percutaneous transluminal coronary angioplasty (PTCA). Dipyridamole-loaded thallium-201 myocardial scintigraphy was undertaken during the acute stage (an average of 5 days after PTCA) and during convalescent stage (an average 24 days after PTCA). Defect was seen in the infarcted areas on early images during the acute stage in all 6 patients, and Tl uptake in the infarcted areas was improved during the convalescent stage in 2 of the 6 patients. In these two patients, fill-in phenomenon was seen in the infarcted area during acute stage when images were acquired after re-injection of Tl-201. These findings suggested that transient disturbance of vascular dilation may occur in the peripheral coronary artery vessels in the infarcted area where recanalization was successfully attained in patients with acute myocardial infarction. (N.K.)