Ventricular ectopic activity with diuretic therapy.
The arrhythmogenic potential of diuretic-induced hypokalemia in patients with uncomplicated hypertension has been controversial. Thirty-two hypertensive patients with previous diuretic-induced hypokalemia, normal 24-hour ambulatory ECG monitoring, and normal exercise testing were treated with 100 mg hydrochlorothiazide (HCTZ) daily (Group 1) to induce hypokalemia or with a combination of HCTZ with amiloride (Group 2) to attempt to maintain plasma potassium levels in the normal range during diuretic therapy. Those Group 1 patients (Group 1A) with increased ventricular ectopic activity (VEA) during HCTZ therapy were subsequently potassium-repleted with amiloride and with supplemental potassium chloride to evaluate the effect of these treatments on VEA. One Group 1 patient died suddenly after 12 days of HCTZ therapy. Autopsy findings suggested an arrhythmic death. Six Group 1 patients who had increased VEA with HCTZ treatment had reductions in VEA with amiloride or supplemental potassium chloride. Group 2 patients did not have a significant increase in VEA. Thus, diuretic therapy appears to cause VEA primarily by electrolyte changes that are induced.
Holland
O B
OB
Department of Internal Medicine, University of Texas Medical Branch, Galveston 77550.
Kuhnert
L
L
Pollard
J
J
Padia
M
M
Anderson
R J
RJ
Blomqvist
G
G
D000328:Adult; D000584:Amiloride / Q000627:therapeutic use; D001145:Arrhythmias, Cardiac / Q000139:chemically induced* / Q000503:physiopathology; D002986:Clinical Trials as Topic; D003645:Death, Sudden / Q000209:etiology; D004338:Drug Combinations; D004562:Electrocardiography; D005260:Female; D006352:Heart Ventricles; D006801:Humans; D006852:Hydrochlorothiazide / Q000009:adverse effects*; D008297:Male; D008875:Middle Aged; D008991:Monitoring, Physiologic; D011189:Potassium Chloride / Q000627:therapeutic use
D004338:Drug Combinations; D006852:Hydrochlorothiazide; D011189:Potassium Chloride; D000584:Amiloride