Biochemical evidence of myocardial injury after severe head trauma.

Serum levels of creatine kinase (CK) and its myocardial isoenzyme (CK-MB) were measured and serial ECG recorded in 24 male and 6 female patients with severe head trauma. All patients were comatose, but no patient sustained a spinal or chest injury. Total CK activity was elevated in at least one sample in each patient. Elevated CK-MB activity was found in 28 patients. The serial CK-MB data did not follow the same pattern as that of patients suffering from myocardial infarctions. The mean CK-MB remained elevated for at least 3 days after injury, although individual patterns were variable. ECG abnormalities included prolonged corrected QT interval (QTc) in 90% and a variety of nonspecific ST segment and T wave changes in 53%. These ECG findings are consistent with other clinical studies of severe neurological disorders, particularly cerebrovascular accidents. The elevated CK-MB activity indicates that ongoing myocardial damage occurs in patients with severe head injury. Although the underlying mechanism is not entirely clear, an excessive release of catecholamines is the most likely mechanism accounting for diffuse myocardial damage, prolonged elevated CK-MB values and the observed ECG abnormalities.