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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 nondipper hypertension.
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.
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 nondipper patients compared to the dippers (39.4±11.5 vs 27.3±7.5 milliseconds and 37.5±9.5 vs 29.2±6.5 milliseconds, P=0.001 and P=0.01, respectively). Tp-e interval and Tp-e/QT ratio were also significantly higher in nondipper patients (97.5±11.2 vs 84.2±8.3 milliseconds and 0.23±0.02 vs 0.17±0.02, all P value <0.001).
Our study revealed that QTd, Tp-e interval and Tp-e/QT ratio are prolonged in patients with nondipper hypertension.
|Age (years)||51.5 ± 8||50.6 ± 5.4||0.2|
|Sex (n,%) males||29 (58%)||17 (56.6%)||0.62|
|Creatinine (mg/dl)||0.92± 0.12||1.1 ± 0.18||0.24|
|LV ejection fraction (%)||63.6± 14.4||61.4 ±8.5||0.24|
|LV mass index (g/m2)||111.6 ± 21.2||147 ±25.7||0.001|
|QT dispersion (QTd) (ms)||27.3±7.5||39.4±11.5||0.001|
|corrected QT dispersion (cQTd)||29.2±6.5||37.5±9.5||0.01|
|Tp-e/QT ratio||0.17 ± 0.02||0.23 ± 0.02||<0.001|
LV: left ventricular