Association of Duration of QRS and Low Ejection Fraction in Patient Presenting with ST Elevated Myocardial Infarction

Background: Preliminary proper diagnosis and rapid revascularization prevent heart failure just after acute myocardial infarction stage by limiting myocardial ischemia and the area at risk. There is voluminous evidence regarding the relationship between heart failure’s Left Ventricular Ejection Fraction and QRS duration, yet, little data exist regarding ischemic heart disease. Objective: Evaluate the relationship between QRS duration and LVEF in ST segment Elevated Myocardial Infarction and assess the discriminative ability of a prolonged QRS duration for low LVEF. Method: Comparative cross-sectional study included 60 patients divided into two groups: first one is prolonged QRS duration or prolonged QRS > 90 msec nominated as group A and normal QRS duration group or QRS ≤ 90 msec nominated as group B. The QRS duration was measured directly from a 12-lead ECG, whereas LVEF was determined by echocardiography, Simpson’s biplane method. The sensitivity, specificity and predictive values calculated by using a two-by-two table. Results: Group A long QRS had a mean QRS duration of 99.30 ± 5.21 msec longer than Group B normal QRS of 78.50 ± 7.56 msec. The mean LVEF was 40.46 ± 7.88% in Group of prolonged QRS and 50.96 ± 9.86% in Group with normal QRS duration Patient with LVEF <40 had QRS >90 msec in 85% while those with LVEF >40 had QRS ≤ 90 in 69.2%. The QRS duration had sensitivity which is 85.7% and specificity which is 69.2 %, Positive Predictive Value of 60% and Negative Predictive Value of 90%, overall accuracies of 75%. It was also reasonable to note relative negative Pearson correlation coefficient of QRS duration and LVEF of -0.649, significant at p < 0.001. Conclusion: QRS duration demonstrates significant association with LVEF in STEMI patients, with a sensitivity of 85.7% and specificity of 69.2% for predicting reduced LVEF (<40%). QRS duration may serve as a simple, non-invasive marker to identify high-risk STEMI patients, facilitating timely and aggressive management in resource-limited settings.