Effect of telmisartan on QT interval variability and autonomic control in hypertensive patients with left ventricular hypertrophy.

Objectives: The aim of the study was to examine the effect of the antihypertensive AT1 receptors antagonist telmisartan on cardiovascular autonomic function and QT dispersion in hypertensive patients with LVH.

Methods: Twenty-five patients (18 males and seven women, mean age 49.8±5.2 years) with mild essential arterial hypertension and LVH were compared with 25 age-matched healthy controls. All the participants underwent a complete clinical examination, including electrocardiogram for QT interval measurements and 24h ambulatory ECG monitoring for measurement of heart rate variability. The ECG, 24h ambulatory ECG, and echocardiogram were repeated after eight weeks of treatment.

Results: At baseline, hypertensive patients showed QT dispersion (p<0.001) and QTc dispersion (p<0.001) significantly higher than control subjects. An eight-week telmisartan treatment significantly reduced blood pressure (p<0.0001), without significant change in left ventricular mass. Telmisartan-based treatment induced an increased vagal activity without significant change of sympathetic activity and a reduction of QT dispersion (p<0.001) and QTc dispersion (p<0.001).

Conclusions: These data suggest that therapy with telmisartan significantly improves the sympathovagal balance increasing parasympathetic activity, and cardiac electrical stability reducing the heterogeneity of ventricular repolarization in hypertensive subjects. These effects could contribute to reduce arrhythmias as well as sudden cardiac death in at-risk hypertensive patients.