ST elevation: telling pathology from the benign patterns.

Benefits of early reperfusion in patients presenting with acute ST elevation myocardial infarction (STEMI) are well known. The American College of Cardiology / American Heart Association guidelines recommend triage decisions are made within 10 minutes of performing initial electrocardiogram (ECG). Since many patients presenting with ischemic symptoms may have ST elevation (STE) at baseline, not all STE signify transmural ischemia. Benign patterns can be easy to find in some cases. However, patients with benign STE at baseline (left ventricular hypertrophy, early repolarization pattern) may have ongoing ischemia and present with Non-ST elevation myocardial infarction (NSTEMI) or even STEMI superimposed on the benign pattern. The ability of clinicians to distinguish between ischemic and non ischemic STE varies widely and is affected by prevalence of such changes in patient population. More studies need to be done to delineate the criteria to clearly distinguish between ischemic and non ischemic ST elevation.