Optimal enzyme test combination for diagnosis of acute myocardial infarction.

One hundred consecutive patients admitted to our cardiology service with the suspected diagnosis of acute myocardial infarction were evaluated with serical enzyme and isoenzyme determinations in an attempt to develop the medically and financially optimal combination of enzyme tests. In patients with onset of chest pain less than 24 hours before admission, creatine phosphokinase MB determination on admission and after 12 hours was sufficient to diagnose of exclude myocardial infarction. One serum LDH isoenzyme determination 24 hours after admission confirmed the diagnosis in 74% of patients.