Pitfalls in diagnosing ST elevation among patients with acute myocardial infarction

Objectives: Patients with ST elevation (STE) in ≥ 2 leads or ST depression (STD) confined to V1-V4 are defined as potential STE myocardial infarction (STEMI). We evaluated the incidence of missed STEMI over an 11-month period. Methods: Consecutive patients with a discharge diagnosis of non STEMI were retrospectively evaluated. Clinical data, ECG and angiographic data were reviewed. Results: Of the 198 patients screened, 140 were included. Forty-nine patients (35%) met the STEMI criteria: 6 (12%) had STD confined to V1-V3, 20 (41%) had STD in V1-V6, 7 (14%) had STE in V1-V3, 2 (4%) had STE in I and aVL, 11 (22%) had STE in inferior leads, and 6 (12%) had STE in V4-V6. Conclusions: A significant percentage of patients met STEMI ECG criteria. A large number of patients with STD in V1-V6 had angiographic evidence compatible with inferolateral (posterior) STEMI equivalent.