Hypomagnesemia in heart failure with ventricular arrhythmias. Beneficial effects of magnesium supplementation

OBJECTIVE: To assess the role of electrolyte imbalance in cardiac arrhythmias associated with congestive heart failure. DESIGN: Serum magnesium and potassium levels, urine magnesium excretion and the incidence of ventricular arrhythmias were assessed throughout the study. The patients who displayed complex arrhythmias after the first week of hospital medication were randomized 2:1 to double-blind magnesium supplementation or placebo. SETTING: The study was carried out in one municipal hospital, providing primary care. SUBJECTS: A total of 588 consecutive patients were screened for eligibility (clinical heart failure >/=6 months; NYHA class II-IV; left ventricular ejection fraction