Electrocardiographic diagnosis of left circumflex artery occlusion and the occlusion site.

In patients with a posteroinferior acute myocardial infarction and both ST depression (in lead V1 or V2) and ST elevation in the inferior leads, it is difficult to differentiate a left circumflex artery occlusion from a right coronary artery occlusion. Furthermore, there is no useful method to identify the obstruction site in the left circumflex artery. In a study of 52 patients with single-vessel left circumflex artery disease, ST elevation in V6 was found to be a useful indicator for left circumflex artery occlusion in such patients. Furthermore, the sum of the ST changes in leads a VF and V2 is useful for identifying the occluded site in the left circumflex artery.