Most fatalities from blunt or penetrating cardiac injuries occur prior to

hospital arrival. The main reversible pathology is acute cardiac tamponade,

which may be present without external signs of injury, abnormal clinical

signs, or ECG abnormalities. The cause of the tamponade is usually a

laceration to a low-pressure cardiac cavity. In recent years the widespread

use of ultrasound in the initial assessment of severely injured patients

has facilitated the early diagnosis of cardiac tamponade and associated

cardiac injuries.