An Observational Study to Identify the Role of ECG in Locating the Occluded Vessel in Patients of Myocardial Infarction with Angiographic Correlation.

ABSTRACT

Background: The electrocardiography (ECG) is considered as a fundamental tool in identifying the location and managing the symptoms of acute myocardial infarction. The aim of the present study is to study different ECG patterns according to the vessel involved and then it is correlated with the angiographic findings. Methods: It is a prospective and observational study conducted on 50 patients suffering from myocardial infarction with elevated ST segment in ECG who subsequently underwent coronary angiography. Based on the various ECG criteria the vessel involved was recognized and then correlated with angiographic findings. The sensitivity and specificity of individual parameters were calculated. Results: The present study demonstrated that ST depression in inferior leads >1mm had maximum sensitivity and specificity in localizing the position of occlusion proximal to S1. Presence of Q wave in aVL had maximum sensitivity and ST depression in the inferior leads showed extreme specificity in patients with occlusion proximal to D1. Presence of Q wave in V4-V6 had 95% specificity and Absence of inferior ST depression presented 89% sensitivity in patients with occlusion in distal S1. Presence of ST depression in aVL showed 98% specificity in patients with distal D1 occlusion. In patients with right coronary artery, ST elevation in LIII>ST elevation in LII and in case of left circumflex occlusion, ST ↑elevation in LII > LIII is the parameter with highest sensitivity and specificity. Conclusion: The ECG in patients with ST elevation myocardial infarction is important not only for defining which patient should receive early reperfusion treatment, but also for deciding the site and degree of acute myocardial injury.