Serum creatine kinase isoenzyme (CK-MB) screening followed by two-dimensional echocardiography (2-DE) was used for the assessment of possible cardiac injury in victims of blunt trauma with acute thoracic or rapid deceleration injury. Of 291 victims evaluated acutely, 58 (20%) had a CK-MB fraction evident within 24 hours after injury. Sixty per cent (35/58) were diagnosed as having 'cardiac concussion' (normal 2-DE) and 40% (23/58) as having 'cardiac contusion' (abnormal 2-DE). 2-DE abnormalities most often involved the right ventricle and were characterized by dyskinesis. Only one of 35 concussion patients (3%) and nine of 23 contusion patients (39%) manifested cardiac arrhythmias within 72 hours after injury (p less than 0.006). Distinction between concussion and contusion has enabled development of a rational acute management protocol. A total of 70 patients with documented blunt cardiac injury (58 evaluated acutely, nine dead on arrival or died in the emergency room, and three delayed presentations) seen at this institution over 4 years are reported, illustrating the full spectrum of blunt cardiac injury.