Relationship between the elastic properties of aorta and QT dispersion in newly diagnosed arterial adult hypertensives.

OBJECTIVE: Afterload is increased in hypertensive patients and increased afterload associated with both ventricular repolarization inhomogeneity and impaired elastic properties of aorta. Thus, we investigated whether QT dispersion (QTd), which is a reflection of ventricular repolarization inhomogeneity, is related to aortic elastic properties in patients with hypertension.

METHODS: Overall 113 patients with newly diagnosed hypertension and 25 normal control subjects were included in this cross-sectional case-controlled study. Aortic strain (AS) and aortic distensibility (AD) were calculated echocardiographically from the derived ascending aorta diameters. Electrocardiograms were recorded in all subjects, and QTd and corrected QTd (cQTd) were then calculated.

RESULTS: Patients as compared with control subjects had lower mean AS and AD (p<0.001, for both). The QT interval maximum and corrected QT interval maximum durations, QTd and cQTd were increased in patients compared with control subjects. Multiple linear regression analysis showed that corrected QTd was independently related to age, left ventricular mass index (LVMI), AS and AD (b=0.204, p=0.030, b=0.219, p=0.026, b=-0.238, p=0.021 and b=-0.208, p=0.032 respectively) in hypertensive patients. The QTd was independently related to AS (p=0.043) and AD (p=0.037), as well as age (p=0.003) and LVMI (p=0.008).

CONCLUSION: The QTd and cQTd were increased in hypertensives. Aortic elastic properties may play a role in increased dispersion of QT and cQT intervals.