Nonarrhythmogenicity of diuretic-induced hypokalemia. Its evidence in patients with uncomplicated hypertension.

Twenty patients aged 33 to 69 years with uncomplicated hypertension, no heart disease, and normal stress test results underwent ambulatory ECG monitoring a month after receiving placebo and two and four weeks after hydrochlorothiazide therapy. Serum potassium level (+/- SEM) averaged 4.4 +/- 0.09 mEq/L after the placebo trial and 3.4 +/- 0.07 and 3.0 +/- 0.06 mEq/L after two and four weeks of therapy, respectively. Sixteen patients had no arrhythmias. Four patients had 329 +/- 140 premature ventricular beats (PVBs) while receiving placebo and 341 +/- 203 and 315 +/- 158 PVBs per 24 hours after two and four weeks of therapy, respectively. Thus, patients with uncomplicated hypertension and no arrhythmias before diuretic therapy did not experience arrhythmias as a result of diuretic-induced hypokalemia of one month's duration. Patients with low-grade ventricular ectopy (VE) before therapy did not progress to higher grades of VE after diuretic treatment for four weeks.