Precordial ST-segment depression in acute inferior myocardial infarction: innocent bystander or a high risk indicator?

ST-segment depression in the anterior precordial leads is seen in roughly one-half of patients with first acute inferior myocardial infarction. Concomitant stenosis of the left anterior descending artery can be detected angiographically in approximately 50% of all patients with inferior infarction whether or not precordial ST-segment depression is present. The presence of precordial ST-segment depression identifies a subgroup of patients with inferior myocardial infarction who have a lower left ventricular ejection fraction and quantitatively more severe abnormalities involving the posterolateral and inferoseptal segments. The contribution of anterior wall ischemia to the genesis of the precordial pattern remains problematic; although most studies to date have not supported this viewpoint, careful quantitative thallium perfusion studies have not been done. Short-term mortality and morbidity seem less favorable in the presence of precordial ST-segment depression, but this has not been substantiated by all authors.