Thiazide-induced hypokalemia. Association with acute myocardial infarction and ventricular fibrillation.

Ten of 59 patients (17%) were receiving a thiazide preparation at the time of an acute myocardial infarction and ventricular fibrillation. Hypokalemia was present in seven of eight patients (87%) receiving thiazides, whereas it was observed in only one of 38 patients (2.6%) not receiving these medications. If hypokalemia is present in patients receiving thiazides who have had an acute myocardial infarction, it should be corrected so as to remove this predisposing cause of ventricular fibrillation.