Blunt cardiac trauma: lessons learned from the medical examiner

The objective of this study was to analyze autopsy findings after blunt traumatic deaths to identify the incidence of cardiac injuries and describe the patterns of associated injuries.

All autopsies performed by the Los Angeles County Forensic Medicine Division for blunt traumatic deaths in 2005 were retrospectively reviewed. Only cases that underwent a full autopsy including internal examination were included in the analysis. The study population was divided into two groups according to the presence or absence of a cardiac injury and compared for differences in baseline characteristics and types of associated injuries.

Of the 881 fatal victims of blunt trauma received by the Los Angeles County Forensic Medicine Division, 304 (35%) underwent a full autopsy with internal examination and were included in the analysis. The mean age was 43 years +/- 21 years, patients were more often men (71%) and were intoxicated in 39% of the cases. The most common mechanism was motor vehicle collision (50%), followed by pedestrian struck by auto (37%), and 32% had a cardiac injury. Death at the scene was significantly more common in patients with a cardiac injury (78% vs. 65%, p = 0.02). The right chambers were the most frequently injured (30%, right atrium; 27%, right ventricle). Among the 96 patients with cardiac injuries, 64% had transmural rupture. Multiple chambers were ruptured in 26%, the right atrium in 25%, and the right ventricle in 20% of these patients. Patients with cardiac injuries were significantly more likely to have other associated injuries: thoracic aorta (47% vs. 27%, p = 0.001), hemothorax (81% vs. 59%, p < 0.001), rib fractures (91% vs. 71%, p < 0.001), sternum fracture (32% vs. 13%, p < 0.001), and intra-abdominal injury (77% vs. 48%, p < 0.001) compared with patients without cardiac injury. Of the 96 patients with a cardiac injury, 78% died at the scene of the crash and 22% died en route or at the hospital.

Cardiac injury is a common autopsy finding after blunt traumatic fatalities, with the majority of deaths occurring at the scene. Patients with cardiac injuries are at significantly increased risk for associated thoracic and intra-abdominal injuries.