Time lapse from estimated onset of acute myocardial infarction to peak serum enzyme activity

In 581 patients with acute myocardial infarction (MI), the time lapse from estimated onset of infarction to estimated peak serum (S) enzyme activity was evaluated. Heat-stable lactate dehydrogenase (LD; E.C. 1.1.1.27) was analyzed every 12 h for 48-108 h after arrival in hospital (n = 581) and creatine kinase (CK; E.C. 2.7.3.2.; n = 224), and creatine kinase subunit B (CK-B; n = 211) were analyzed every 6 h for 48 h. Peak S-LD was observed between 14 and 110 h after estimated onset of MI (mean 46.6 +/- 0.6 h), peak S-CK was observed between 8 and 58 h (mean 25.0 +/- 0.6 h), and peak S-CK-B was also observed between 8 and 58 h (mean 22.8 +/- 0.7 h) after onset. In 86% of patients, peak LD was reached within 60 h after onset of MI, in 78%, peak CK was reached within 30 h, and in 82%, peak CK-B was observed within 30 h after onset of MI. A weak correlation was found between duration of pain and time lapse to S peak enzyme activity (r = 0.25 -0.27; p less than 0.001), while there was no correlation between S peak activity and time lapse from onset of MI to S peak activity. It is concluded, that although in the majority of patients with MI, peak serum-enzyme activity is reached within a predictable amount of time after estimated onset of MI there is wide variation, difficult to establish from the clinical course, among individual patients.