Value of the ST-T segment in lead V4R in inferior wall acute myocardial infarction to predict the site of coronary arterial occlusion

Abstract

The treatment of acute myocardial infarction (AMI) has changed dramatically with the introduction of thrombolytic therapy, immediate angioplasty and emergency coronary artery bypass surgery. Several studies1e3 have shown that the success rate of these procedures depends on the time interval between the onset of complaints and the achievement of reperfusion. In patients admitted with an inferior wall AMI, the coronary artery causing the AM1 can be the right or the left circumflex artery. Our previous investigations, as well as those of others,4-6 have shown that the recording of lead V4R in the acute phase of an inferior wall AM1 can distinguish those patients with a proximal occlusion of the right coronary artery from those with an occlusion of the distal right or left circumflex artery, the first group of patients showing ST-T-segment elevation I1 mm in lead V4R. However, it is not possible to differentiate between occlusion of a distal right coronary artery and a circumflex artery using this criterion. In these patients (possible candidates for intracoronary thrombolytic therapy), coronary arteriography might start with the “wrong” coronary artery leading to a delay in reperfusion. Retrospectively, we have analyzed the configuration of the ST-T segment in lead V4R to determine if changes in the ST-T segment can help predict the site of coronary occlusion in inferior wall AMI.