Abstract: AIM To assess the relationship of coronary flow reserve (CFR) in the non-infarcted myocardium and left ventricular functions in patients with acute myocardial infarction (AMI) undergoing coronary intervention. METHODSWe enrolled 22 AMI patients undergoing coronary intervention. CFR in the non-infarcted myocardium was compared with that in infarcted myocardium and normal myocardium by dobutamine real-time myocardial contrast echocardiography at 1 week following coronary angioplasty. Left ventricular functions were assessed by two-dimensional echocardiography. Patients were divided into two groups according to the CFR value of the non-infarcted myocardium and changes of left ventricular functions were compared between groups. RESULTSCFR value decreased in non-infarcted myocardium compared with control group. Furthermore, there was a significant negative correlation between CFR in the non-infarcted region and left ventricular end diastolic volume (LVEDV) at 6 months following coronary angioplasty. CONCLUSIONMicrovascular dysfunction is commonly observed in the non-infarcted myocardium in AMI patients. The CFR value in the non-infarcted myocardium can predict left ventricular function following AMI.