Electrocardiographic characteristics of posterior myocardial infarction in comparison to angiographic findings

BACKGROUND: Myocardial infarction (MI) is a cardiac cell death following the imbalance of supply and demand. Electrocardiography (ECG) is a diagnostic test for MI and can help the clinicians to estimate the severity and size of infarction, to suggest the artery related to the infarct and localize the pathology. The aim of this study is to evaluate the diagnostic value of ECG in posterior MI (PMI) compared with angiographic findings. METHODS: In a prospective observational study, using simple sampling patients with diagnosis of PMI (ST elevation in at least two consecutive leads V۷, V۸, and V۹) were enrolled and all standard ۱۲ leads and also V۷, V۸, V۹ and right leads, including V۳R and V۴R were recorded and angiography was performed. ECG changes were recorded and compared with angiography findings. RESULTS: In this study, totally ۱۳۸ patients were enrolled (mean ± standard deviation age of ۶۵.۰۰ ± ۱۲.۹۷ and ۷۶.۸% male). Left circumflex artery (LCX), right coronary artery (RCA) and left anterior descending artery (LAD) occlusions occurred in ۶۵.۹, ۵۰.۷, and ۲۹ percent respectively. Patients with LCX occlusion had a significantly higher frequency of ST elevation in V۵, V۶, I and AVL (P ≤ ۰.۰۰۱). Patients with RCA occlusion had a significantly higher frequency of ST elevation in V۱, V۳R, and V۴R and also ST depression in V۵ and V۶ (P ≤ ۰.۰۰۱). CONCLUSION: In PMI, there is a relationship between ECG findings and different coronary artery occlusions. Hence that ECG is a useful tool to predict the LCX or RCA occlusion in PMI. 

Keywords:

Angiography , Coronary Artery , Electrocardiography , Posterior Myocardial Infarction