Comparison of in hospital outcome of patients with and without distorted terminal portion of QRS complex on initial electrocardiogram in ST segment elevation myocardial infarction with GRACE scoring assessment

Abstract

Distorted terminal portion of QRS complex on initial electrocardiogram in ST segment elevation myocardial infarction is a strong predictor of in hospital adverse outcome This observational prospective study was carried out in the department of cardiology, BSMMU, Dhaka from July 2014 to June 2015 to analyse admission ECG in patients of STEMI based on terminal portion of QRS complex and find out inhospital death, heart failure, cardiogenic shock and recurrent myocardial infarction, with GRACE scoring assessment. Total 60 patients with STEMI (age 54.33±10.37, 55M/5/F) were included in this study after analysing the selection criteria. We defined two ECG groups according to absence of distortion of terminal QRS (Group-I) and presence of distorted terminal QRS (Group-II) in two or more adjacent leads. Group-II further divided into pattern-A – J point originating at ³50% of height of R wave in leads with qR configuration and pattern B- S wave is absent in leads with RS configuration. Global Registry of Acute Coronary Events (GRACE) risk score was evaluated and compared in between two groups. Out of 60 patients of STEMI, 30 patients had distortion of QRS complex. There were 7 deaths, 16 heart failure, 3 cardigenic shock and no recurrent myocardial infarction. Hospital mortality and heart failure were found to be significantly higher in distorted QRS group (1 vs. 6 patients p=0.04; 4 vs. 12 patients p=0.02; respectively), cardiogenic shock of both groups did not show significant difference (0 vs. 3 patients p=0.075). Multiple logistic regression analysis using hospital mortality as dependable variable and all studied risk factors were independent variables, QRS distortion on admission ECG and Killip class were only variable found to be statistically significant (OR=7.25, p value < 0.05 ; OR=16.25, p value< 0.05 respectively). GRACE risk score was significantly high in distorted QRS group and low in without QRS distorted group (6 vs 15 patients p=0.014; 6 vs 16 patients p=0.007; respectively). Intermediate GRACE score did not show any statistically significant difference between two groups (p=0.77). Careful analysis of ECG which is simple, cheap, universally available bed side investigation may offer important prognostic information in patients with STEMI and would help in deciding which patients should go urgent myocardial revascularization procedure. Assessment of GRACE risk scoring is strongly encourage in everyday clinical practice as it provides reliable identification of STEMI patients who are at high risk of death. Bangladesh Medical Res Counc Bull 2022; 48(3): 211-218