The relationship between type of balloon catheter and reperfusion arrhythmia (RA) of 97 patients with acute myocardial infarction (AMI) ,who had received direct PTCA has been studied. The incidence of RA in common balloon catheter treated group is 55. 4%,while that in perfusion balloon catheter treated group is 34. 4% and the extent of RA is less severe. During direct PTCA, perfusion balloon catheter can reduce the incidence and severity of RA.