Effect of Hydrochlorothiazide Therapy on Cardiac Arrhythmias in African-American Men With Systemic Hypertension and Moderate to Severe Left Ventricular Hypertrophy

The effect of hydrochlorothiazide therapy on ventricular arrhythmias was studied in 45 hypertensive African-American men with moderate to severe left ventricular (LV) hypertrophy. After medication washout, patients were treated with placebo followed by hydrochlorothiazide. Clinical, biochemical, and 48-hour ambulatory electrocardiographic data was collected after each treatment phase. Signal-averaged electrocardiograms were recorded in a subgroup of 24 patients. Average LV posterior wall thickness was 15 ± 1.1 mm, septum 16 ± 2 mm, LV mass 420 ± 90 g, and LV mass index 212 ± 51 g/m2. Systolic blood pressure (BP) was 168 ± 18 mm Hg after the placebo phase and 146 ± 15 mm Hg after hydrochlorothiazide; diastolic BP was 103 ± 6 mm Hg and 89 ± 9 mm Hg, respectively. Serum potassium decreased significantly from 4.2 ± 0.4 mmol/L to 3.7 ± 0.6 mmol/L after hydrochlorothiazide therapy. The average hourly incidence of ventricular premature contractions was 22 with placebo and 25 with hydrochlorothiazide. There were 3 and 1 couplets and 0.2 and 0.2 runs of ventricular tachycardia per patient per hour, respectively. Variables of signal-averaged electrocardiography did not differ between the 2 treatments. Thus, in hypertensive African-American men with moderate to severe LV hypertrophy, hydrochlorothiazide does not worsen ventricular arrhythmias or signal-averaged electrocardiographic variables. Cardiol 1996;78:886–889)