Inferior Subtle ST Elevation. Would You Activate Cardiac Catheterization Laboratory?

Background: According to guidelines, patients with inferior myocardial infarction only qualify for emergent reperfusion if they have at least 1 mm of ST elevation in two contiguous inferior leads. Although this has remained the standard for years, acute coronary occlusion may occur in patients with nondiagnostic ST elevation. Accordingly, a paradigm change is instigated, shifting the focus to physiopathology (occlusion myocardial infarction) rather than ST criteria.

Case Report: A middle-aged man presented to our emergency department with chest pain and subtle nondiagnostic electrocardiography (ECG) changes in inferior leads. A careful examination of aVL to detect ST depression in this lead was the key to successfully diagnosing occlusion myocardial infarction, allowing early revascularization of an occluded right coronary artery. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Accurate diagnosis of coronary occlusion by means of ECG can be challenging in certain situations, as acute myocardial ischemia may occur in patients with nondiagnostic ST elevation, especially in the inferior leads. A thorough examination of aVL searching for ST depression is essential in these situations.