CPK-MB isoenzyme determinations: diagnostic and prognostic value in evaluation of blunt chest trauma.

The incidence of myocardial contusion in patients with blunt chest trauma was examined. The criterion used for diagnosing contusion--actual cellular injury--was based on detection of the MB-isoenzyme of creatine phosphokinase, a sensitive and specific marker for cardiac cellular injury. Forty-nine patients with blunt chest trauma were evaluated using this diagnostic approach. Twenty-six demonstrated measurable serum levels of MB-CPK. Electrocardiographic (ECG) evaluation of this subgroup revealed that 85% exhibited anatomically localized ST-T wave abnormalities while 15% showed nonlocalized and nonspecific changes. Sixty-eight percent of those with localized abnormalities demonstrated ST segment changes depicting injury, most of which were localized to the anterior septal leads. The remaining 23 patients demonstrated non-detectable serum levels of MB-CPK and were classified as cardiac concussion on the basis of other clinical criteria. Twenty-six percent with concussion exhibited anatomically localized ECG changes. The remaining 74% had nonlocalized and nonspecific ECG changes.