Evaluation of Tp-e interval and Tp-e/QT ratio in patients with non-dipper hypertension

Aims: Non-dipper hypertension is associated with increased cardiovascular morbidity and mortality. Several studies have suggested that the interval from the peak to the end of the electrocardiographic T wave (Tp-e) may correspond to the transmural dispersion of repolarization and that increased Tp-e interval and Tp-e/QT ratio are associated with malignant ventricular arrhythmias. The aim of this study was to evaluate ventricular repolarization by using Tp-e interval and Tp-e/QT ratio in patients with non-dipper hypertension.

Materials and method: This study included 80 hypertensive patients. Hypertensive patients were divided into two groups: 50 dipper patients (29 male, mean age 51.5?±?8 years) and 30 non-dipper patients (17 male, mean age 50.6?±?5.4 years). Tp-e interval and Tp-e/QT ratio were measured from the 12-lead electrocardiogram. These parameters were compared between groups.

Results: No statistically significant difference was found between two groups in terms of basic characteristics. In electrocardiographic parameters analysis, QT dispersion (QTd) and corrected QTd were significantly increased in non-dipper patients compared to the dippers (39.4?±?11.5 versus 27.3?±?7.5?ms and 37.5?±?9.5 versus 29.2?±?6.5?ms, p?=?0.001 and p?=?0.01, respectively). Tp-e interval and Tp-e/QT ratio were also significantly higher in non-dipper patients (97.5?±?11.2 versus 84.2?±?8.3?ms and 0.23?±?0.02 versus 0.17?±?0.02, all p value <0.001).

Conclusion: Our study revealed that QTd, Tp-e interval and Tp-e/QT ratio are prolonged in patients with non-dipper hypertension.