Prolonged T_peak-end and T_peak-end/QT ratio as predictors of malignant ventricular arrhythmias in the acute phase of ST-segment elevation myocardial infarction: A prospective case-control study

Background Prolonged T_peak-end (the interval from the peak of the T wave to the end of the T wave) and T_peak-end/QT ratio have been shown to be markers of arrhythmogenesis in various cardiac disorders. Objectives The purpose of this study was to evaluate the utility of T_peak-end and T_peak-end/QT ratio at admission in patients with acute ST-segment elevation myocardial infarction (STEMI) in predicting malignant ventricular arrhythmias. Methods The study group included 50 patients presenting with STEMI, in whom T_peak-end and T_peak-end/QT ratio were measured at admission; these patients were monitored for arrhythmias with a continuous electrocardiogram in the intensive care unit for 48 hours, and 50 healthy individuals acted as controls. Results The T_peak-end (0.11 ± 0.04 seconds vs 0.08 ± 0.006 seconds; P <.0010) and T_peak-end/QT ratio (0.30 ± 0.06 vs 0.21 ± 0.02; P <.001) were prolonged in patients with STEMI. Three patients with STEMI who sustained ventricular fibrillation (VF) within 24 hours of admission had prolonged corrected QT interval (0.39 ± 0.04 seconds vs 0.46 ± 0.13 seconds; P =.019), T_peak-end (0.10 ± 0.02 seconds vs 0.20 ± 0.11 seconds; P <.001), and T_peak-end/QT ratio (0.26 ± 0.05 vs 0.41 ± 0.09; P <.001) as compared with patients with STEMI without VF. T_peak-end > 0.1 seconds and T_peak-end/QT ratio > 0.3 predicted VF with a sensitivity of 100%. However, the T_peak-end/QT ratio had a higher specificity (82.9% for T_peak-end/QT ratio vs 44.7% for T_peak-end) and accuracy (84% for T_peak-end/QT ratio vs 48% for T_peak-end). Conclusion T_peak-end and T_peak-end/QT ratio are prolonged in patients with STEMI compared with healthy individuals, and T_peak-end > 0.1 and T_peak-end/QT ratio > 0.3 predict malignant ventricular arrhythmias within 24 hours of STEMI.