Evaluation of QT dispersion and T-peak to T-end interval in patients with early-stage sarcoidosis.

INTRODUCTION AND AIM Sarcoidosis increases inhomogeneity in ventricular repolarization due to the presence of sarcoid granuloma, which significantly correlates with ventricular fibrillation. Various studies have suggested that the interval from the peak to the end of the electrocardiographic T wave (T-peak to T-end [Tpe] interval) may correspond to the transmural dispersion of repolarization and that increased Tpe interval and Tpe/QT ratio are associated with malignant ventricular arrhythmias. The present study hypothesized that QT and Tpe intervals are significantly prolonged in sarcoidosis patients without apparent cardiac involvement. METHODS The study population consisted of 54 patients (37 female; mean age 43.4±10.6 years) under follow-up for sarcoidosis and 56 healthy subjects (37 female; mean age 42.4±8.6 years). RESULTS There was no statistically significant difference between the groups in maximum QT interval, QT dispersion or corrected QT (QTc) interval, but QTc dispersion and Tpe interval were significantly prolonged in the sarcoidosis group compared to the control group (QTc dispersion 59.9±22.5 and 44.4±23.8, respectively, p=0.001; Tpe interval 79.4±9.3 and 70.7±7.03, respectively, p<0.001). We also found that the Tpe/QT ratio was significantly higher in sarcoidosis patients compared to the control group (0.21±0.02 and 0.18±0.23, respectively, p<0.001). CONCLUSION Our study revealed that QTc dispersion, Tpe and Tpe/QT ratio were greater in sarcoidosis patients compared to the control group. To our knowledge, the present study is the first to use Tpe interval analysis in patients without cardiac involvement in sarcoidosis. Tpe interval and Tpe/QT ratio may be promising markers for cardiovascular morbidity and mortality due to ventricular arrhythmias in patients with and without cardiac involvement in sarcoidosis.