PROLONGED QRS DURATION>140 MILLISECONDS AS A PREDICTOR OF LEFT VENTRICULAR SYSTOLIC DYSFUNCTION IN PATIENTS WITH LEFT BUNDLE BRANCH BLOCK

Abstract

Objective: To determine the diagnostic accuracy of prolonged QRS duration >140 milliseconds (ms) on electrocardiography (ECG) for diagnosing left ventricular systolic dysfunction (LVSD) in patients of left bundle branch block (LBBB). Methodology: This cross-sectional study included 128 patients with LBBB. QRS duration was calculated in every patient and duration >140ms was considered as positive criterion for predicting LVSD. Echocardiography was done in all patients to diagnose LVSD. Specificity, sensitivity, negative predictive value (NPV) and positive predictive value (PPV) of QRS duration>140 ms on ECG in predicting LVSD taking echocardiography as a standard were calculated by using 2x2 contingency table. Results: An ECG QRS duration>140 ms criterion was 76.3% sensitive and 75.4% specific in diagnosing LVSD while PPV was 72.6% and the NPV of 78.8% in diagnosing LVSD. Conclusion: An ECG QRS duration > 140 ms is reasonable in predicting LVSD.