Electrocardiographic and angiographic characteristics of patients with acute solitary posterior myocardial infarction

Objective: To investigate electrocardiographic (ECG) and angiographic characteristics of patients with acute solitary posterior myocardial infarction. Patients complicated by inferior wall or right ventricular infarction were excluded.

Methods: ECG and angiographic changes in 11 patients with acute solitary posterior myocardial infarction admitted to our emergency room from 2001 to 2006 were analyzed.

Results: Besides typical ST segment elevation in V(7)-V(9) leads, other ECG manifestations in these patients included V(1)-V(2) R/S > or = 1 (9/11, 81.8%), 1 - 2 mm ST depression in V(1)-V(4) (5/11, 45.5%), 0.5 - 1.5 mm ST elevation in I, aVL leads (4/11, 36.4%) and 0.5 - 1.5 mm ST elevation in V(5)-V(6) leads (5/11, 45.5%). Coronary angiography showed that left circumflex artery (LCX) was the infarction related artery in all cases. The infarction area located before OM1 origination in 1 patient with a 95% pipe-like stenosis (1/11), after OM1 origination in 6 patients (6/11, 4 with total occlusion, 1 with sub-total occlusion and 1 with 90% long length stenosis), in OM1 in 4 patients (4/11, 2 with total occlusion, 1 with sub-total occlusion and 1 with 95% local stenosis). There were 3 patients (27.3%) with single vessel lesion, 4 patients (36.4%) combined with left anterior descending artery (LAD) lesion, 2 patients (18.2%) combined with right coronary artery (RCA) lesion and 2 patients (18.2%) combined with LAD and RCA lesions.

Conclusions: Acute posterior myocardial infarction should be suspected with V(1)-V(2) R/S > or = 1 and V(1)-V(4) ST depression in standard 12 leads ECG. Besides symptoms and cardiac enzyme measurements, recording posterior leads electrocardiogram and performing coronary angiography will help to make the correct diagnosis.