Cardiac contusions caused by blunt chest trauma:

B. Occur in up to 20% to 40% of patients with major blunt thoracic trauma.

D. Demonstrate arrhythmia as the most common complication

DISCUSSION: Cardiac contusions are often difficult to diagnose, but have been estimated to occur in 5% of major trauma patients, and up to 20% to 40% of patients with severe blunt chest injury. The difficulty in diagnosing cardiac contusions is that they remain a pathologic diagnosis, confirmed only at autopsy or on direct cardiac examination. The injury may vary from superficial epicardial petechiae to complete transmural damage. Although significant myocardial injuries, such as ventricular rupture, coronary vessel thrombosis, and valvular disruption, have been reported, the most common clinically significant result of cardiac contusion is the occurrence of arrhythmias. Hence, an initial electrocardiogram (ECG) and subsequent continuous cardiac monitoring for at least 24 hours is generally recommended. Alternative methods of diagnosing myocardial contusion include creatine phosphokinase cardiac isoenzymes (CPK-MB), two-dimensional echocardiography, gated ventricular scintigraphic angiography (GVA), radioactive thallous chloride ( 201Tl) uptake, and right ventricular monitoring. Unfortunately, none of these tests is adequately sensitive or specific in the diagnosis of cardiac contusion, and their correlation with the presence of arrhythmias or ECG changes is also imprecise.