Electrocardiographic characteristics of patients with inferior myocardial infarction but angiographically normal coronary arteries

Normal coronary arteries were found in 22 (5.8%) of 379 patients presented with acute inferior myocardial infarction. These patients were significantly younger, had less cardiovascular risk factors, better systolic heart function, and lower cardiac enzymes level. Electrocardiography significantly showed more (1) ratio of ST-segment elevation in II/ III ≥ 1; (2) isoelectric ST-segment in I; (3) ST-segment elevation in I; and less (4) paroxysmal atrial fibrillation; (5) ST-segment depression in I; and (6) ST-segment elevation in V4R. In conclusion, this subset of patients had clinical features suggestive of smaller infarct size compared with those suffering from atherosclerotic disease. They may have more left circumflex artery involvement and distal right coronary artery occlusion, as deduced from electrocardiography.