Myocardial Infarction or Acute Myopericarditis

To the Editor.—  Differentiating myocardial infarction from acute myopericarditis may be equivocal. Hanson et al (1982;248:2313) described chest pains and ECG, serum enzymatic, and technetium Tc 99m pyrophosphate scan changes of myocardial injury in a young athlete. Diagnosis of acute myocardial infarction was made, despite there being no evidence of coronary atherosclerosis or spasm; a finding of myocardial bridging was not anatomically related to that myocardial injury. In fact, all findings in this patient concur as well with acute infectious myopericarditis. Serial ECGs showed typical changes of "acute pericarditis": rather widespread initial ST-segment elevations, followed by more localized T-wave inversions^1,2; no Q waves appeared despite a conspicuous elevation of creatine kinase MB level. Creatine kinase MB elevation is detected in 70% of patients who have acute myopericarditis with ST-segment elevation,² and the enzyme release simulates that in myocardial infarction— it is of short duration, not exceeding six days.