The prevalence and significance of cardiac injury following blunt chest trauma is largely unknown. Although electrocardiography (ECG) and creatinine phosphokinase isoenzyme (CPK-MB) determination have traditionally been used in determining cardiac injury, recent developments in two-dimensional echocardiography (ECHO) as a noninvasive diagnostic tool have led to its use in detecting structural cardiac damage following trauma. In an attempt to determine the occurrence and consequences of cardiac injury we prospectively evaluated 68 patients at one institution using ECHO, serial ECG, and serial CPK-MB determinations in the first 3 days following hospital admission. Patients were selected who had evidence of blunt chest injury on examination or by mechanism of injury. The mean age of the 68 patients was 36.3 +/- 19.6 years and the mean Injury Severity Score, 21.5 +/- 11.6. Forty-nine patients (72%) were found to have an abnormal ECHO, ECG, or CPK-MB (greater than 3%). Eighteen patients (26%) had abnormal ECHOs consisting of seven right ventricular contusions, three left ventricular contusions, three contusions of both chambers, four pericardial effusions, and one small ventricular septal defect. Only three contusions were associated with elevated CPK-MB and seven with abnormal ECGs. Abnormalities of ECG included 18 patients with S-T, T wave changes, axis shifts (11 patients), and bundle branch or hemiblocks (10 patients). No patient died or experienced serious morbidity as a result of their cardiac injury, including 12 patients who underwent surgical procedures with general anesthesia within 30 days of admission.(ABSTRACT TRUNCATED AT 250 WORDS)