Here we present a case of a 70-year-old man with acute myocardial infarction caused by left anterior descending artery occlusion presenting as ST elevation in the inferior leads that suggested an occlusion of the right coronary artery. In contrast, coronary angiography results indicated a complete occlusion of the proximal left anterior descending coronary artery. We reported our observation in electrocardiographic data and coronary angiography and its changes after a percutaneous coronary intervention, and then we discuss its pathophysiologic mechanism.