DIAGNOSTIC ACCURACY OF ELECTROCARDIOGRAM IN DETECTING THE CULPRIT CORONARY IN ACUTE ST ELEVATED MYOCARDIAL INFARCTION

Abstract

Objective: To determine diagnostic accuracy of electrocardiogram (ECG) in detecting the culprit coronary in acute ST elevated myocardial infarction (STEMI).
Introduction: Cardiovascular diseases (CVDs), especially coronary heart disease (CHD), have assumed epidemic proportions worldwide. In making the clinical decision for the early management in patients with acute myocardial infarction specific indicator is needed. Ideally, this indicator should be simple, quick, reliable, noninvasive, inexpensive, and easily applicable to all the patients. Coronary Angiography which is the gold standard to detect the culprit vessel invasive, expensive, requires skilled personnel, is time consuming and involves radiation exposure. This study will depict the importance of knowing culprit artery responsible for STEMI before putting the patient to invasive coronary angiography and in some cases; it can categorize the group patients who are at higher risk of considerable damage to the myocardium. Only few studies have examined the predictive utility of ECG in predicting the culprit vessel hence this study was carried out to find out the diagnostic accuracy of ECG in comparison to coronary angiography in predicting the culprit coronary in acute STEMI in resources limited setting of rural central India.
Materials and Methods: This was a hospital based crossectional study which was conducted in rural hospital of central India from October 2016 to May 2018, included 168 patients of acute ST elevated myocardial infarction who underwent coronary angiography (CAG). Standard ECG criterias for localization of culprit vessel occlusion site were specified and the culprit coronary was predicted on admission electrocardiogram. Subsequently the study subjects were subjected to coronary angiography and the results of coronary angiography were compared with those predicted by electrocardiogram. Correlation between ECG and CAG was done using Cohen’s- Kappa statistical analysis method.
Results: The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of ECG for detecting LAD as a culprit artery were 94.1%, 96.4%, 96.3% and 94.2% respectively. Diagnostic accuracy of ECG to detect LAD as culprit artery was 95.2% while it was 79.2% for RCA and 84.2% for LCx. The sensitivity, specificity, PPV and NPV for detecting RCA as a culprit coronary was 80%, 74.3%, 61.9% and 84.2% respectively. The ECG has 84.2% sensitivity and 57.8% specificity, 61.9%PPV and 84.2% NPV for predicting LCx as a culprit  artery. Majority of study subjects 85 (50%) had single vessel disease, 34 (20.2%) had double vessel disease and 24 (14.3%) had triple vessel disease while 25 patients had normal coronaries/ insignificant CAD.
Conclusion:ECG information can be readily used to predict the culprit coronary in acute ST elevated myocardial infarction inresource poor setting areas for coronary angiography, it can also tell the complications in patients of acute MI before thrombolysis, if RCA is predicted to be involved