[Factors predictive of early mortality after acute myocardial infarction]

(1) To define the clinical and laboratory findings predictive of early mortality after myocardial infarction (AMI), 100 consecutive patients were studied. (2) To elucidate the serum potassium (K) concentration and its clinical significance after AMI, 38 patients were studied.

(1) The 30-day mortality was greater for women than for men, for patients with diabetes mellitus than for those without, and for patients with previous MI than for those without. Clinical and laboratory findings predictive of early mortality were cardiogenic shock, congestive heart failure, perforation or rupture of the ventricle, and presence of bundle branch block and extensive anterior AMI on electrocardiogram. The presence of bradyarrhythmia, ventricular tachyarrhythmias, and high blood levels of peak creatinine phosphokinase (CPK) or myosin or atrial natriuretic peptide (ANP) were not independent predictors of early mortality. Patients complicated with congestive heart failure showed higher levels of peak CPK and ANP and patients with cardiogenic shock showed higher levels of ANP. (2) Serum K concentration was lower on admission than the following days, and it showed a negative correlation with plasma epinephrine. The lower serum K was accompanied with more severe ventricular arrhythmias on 24-hour electrocardiogram.

(1) Early mortality after AMI is related to left ventricular function rather than to arrhythmias. (2) Serum K is lower in the early phase of AMI and is related with plasma catecholamines and severe ventricular arrhythmias.