Malignant arrhythmias in relation to values of serum potassium in patients with acute myocardial infarction

Abstract The relationship between levels of potassium in the serum and the development of malignant arrhythmias was examined in a retrospective study involving 1011 patients presenting with acute myocardial infarction. Thirteen percent of the overall patients studied had significant hypokalemia (k P P = 0.01) and a lower incidence of malignant arrhythmias (50.5% versus 63.5% — P = 0.002). No correlation was found between treatment with either digitalis or diuretics and malignant arrhythmias. Size and location of infarcted areas was found to have a direct relationship with development of arrhythmias. Size and location of infarctions, however, were not found to be related to levels of potassium in the serum. Our findings support and clarify earlier suggestions establishing the levels of potassium in the serum as an important causative factor, together with size and location of infarctions, in the development of malignant arrhythmias.