Prognostic Significance of aVR Lead and QTc Prolongation in Patients with Early Repolarization

<i>Background and Objectives</i>: Early repolarization (ER), previously considered benign for many years, is now recognized as a substantial risk factor for malignant arrhythmia, coronary artery disease, and mortality. The ER pattern, previously regarded as a benign electrocardiographic characteristic, has lately been demonstrated to have a strong association with malignant arrhythmias, coronary artery disease, and elevated death rates. This study seeks to illustrate the prognostic significance of QT interval (QTc) prolongation on electrocardiograms for acute coronary syndrome and death in emergency cases. Prolongation of QTc duration on electrocardiography in emergency room cases may serve as a possible predictor for acute coronary syndrome and mortality. <i>Materials and Methods</i>: A retrospective study was conducted on 924 patients diagnosed with ER in the emergency department from 2020 to 2023. The QTc durations, serum glucose levels, troponin I levels, and additional auxiliary data of the patients were assessed. The alteration in the aVR derivation, often overlooked and deemed insignificant, was compared with clinical severity in ER cases. <i>Results</i>: The average age of the 924 patients in the study was 48.43 (9.65) years, with 30.7% being female. In the non-cardiac group, the mean age was 51.67 (7.98) years, with 738 females (31.9%). The QTc interval in the patient group was 409.54 (33.46) ms, while in the control group it was 411.57 (27.91) ms (<i>p</i> < 0.001). The one-year death rate was 49 (5.3%) for the ER group and nine (0.9%) for the follow-up group. The most common comorbid condition in both groups was tobacco and/or tobacco product intake. Univariate and multivariate regression analyses conducted for both ER types and mortality indicated that QTc prolongation may serve as a predictive factor (<i>p</i> < 0.001). The sensitivity and specificity of prolonged QTc in predicting acute coronary syndrome and mortality were determined to be 76% at the lowest and 98% at the highest levels in ER cases (<i>p</i> < 0.001). The Kaplan-Meier survival analysis for ER types revealed 321 days for the horizontal type and 363 days for the ascending type. <i>Conclusions</i>: Prolonged QTc duration in early repolarization cases may serve as an independent predictor of acute coronary syndrome and mortality.