Hypokalaemia and ventricular fibrillation in acute myocardial infarction

Abstract

Serum potassium concentrations obtained on admission to hospital were inversely related to the incidence of ventricular fibrillation in. 289 women and 785 men with acute myocardial infarction, 92 ofwhom developed ventricular fibrillation. Hypokalaemia (serm potassium concentration ≤3·5 mmol/1) was found in 122 patients (11·4%). The incidence of ventricular fibrillation was significantly greater in patients with hypokalaemia compared with those classified as normokalaemic (serum poussium concentration ≥ 3·6 mmol/1) (17.2% v 7.4%). The increased risk of ventricular fibrillation in the hypoklaemic group was about the same for women and men. While they were in hospital patients with hypokalaemia developed ventricular fibrillation significanty earlier than did normokalaemic patents (median 0·3 hours v 7 hours). Hypokalaemia was more common in Women (17·3%) than in men (9·2%), and 55% of the hypokalaemic patients had been treated with diuretics before admission compared with 22% of the normokalaemic group. Hypokalaemia on admission to hospital predicts an increased likelihood and early occurrence of ventricular fibrillation in patients with acute myocardial infarction.