T wave peak to T wave end interval is prolonged in patients with atrioventricular nodal reentry

Atrioventricular nodal reentry tachycardia (AVNRT) is known to be associated with increased risk of susceptibility for ventricular arrhythmias and sudden death. Studies indicate that prolongation of the interval between the peak and end of the T wave (Tpeak to Tend, Tp-e) on the 12-lead ECG is a marker of ventricular arrhythmogenesis. The aim of this study was to assess ventricular repolarization in patients with AVNRT by using Tp-e interval, Tp-e/QT ratio, and Tp-e/QTc ratio. Patient records of Bursa Postdoctorate Training and Research Hospital were retrospectively analyzed. Electrocardiogram of 62 patients, who were diagnosed with AVNRT by electrophysiological study, were obtained and scanned. T wave peak to end interval, QT and corrected QT intervals and some other ECG intervals were measured. Electrocardiograms by age and sex were matched with 34 healthy individuals who were compared as controls. Patients with critical coronary stenosis, moderate or severe valvular disease, left and/or right heart failure, left and/or right ventricle hypertrophy, atrial fibrillation, right or left bundle block or patients who got pacemaker or ICD implanted were excluded from this study. Both groups did not differ in patient demography. Mean values for AVNRT patients and control group were: QT (362.7±43.7 vs 364.1± 34.1), QTc (417.8±43.2 vs 438.3±44.2) and Tp-e interval (83.5±16.6 vs 77.0±9.7). Tpe/QT and Tp-e/QTc ratio were also higher in the AVNRT group. T wave peak to end interval is a measure of transmural dispersion of repolarization in the left ventricle and accepted as a surrogate for increased risk of ventricular arrhythmogenesis. Tp-e/QT and Tp-e/QTc are relatively new markers; which also indicate repolarization defects. Our results show that Tpe (p=0.018), Tp-e/QT (0.23 vs 0.21; p=0,008) and Tp-e/QTc (0.20 vs 0.17; p=0.000) were significantly higher in AVNRT group; which correspond to previous studies about strong relationship between AVNRT and ventricular arrhythmia.