Serum potassium concentrations are inversely related to ventricular, but not to atrial, arrhythmias in acute myocardial infarction

In a study of 1033 consecutive patients with acute myocardialinfarction, serum potassium concentrations were determined onadmission to hospital and studied with respect to the subsequentoccurrence of atrial fibrillation and flutter and of ventriculartachycardia and fibrillation. The study cohort fulfilled theinclusion criteria for the Norwegian timolol trial in whichthey later took part. In multivariate analysis, with serum potassiumconcentrations as a continuous variable, age, the presence ofventricular tachycardia and fibrillation, and maximum levelof aspartate aminotransferase greater than four times the upperlimit of normal were significantly associated with the occurrenceof atrial fibrillation and flutter, while serum potassium concentrationwas not. Serum potassium concentrations and time from onsetof the infarction to hospital admission were significantly negativelyassociated with the occurrence of ventricular tachycardia andfibrillation; while age, cardiomegaly, transient hypotension,pathological Q-waves in the electrocardiogram, atrial fibrillationand flutter, and ventricular premature beats were positivelyrelated to these arrhythmias.