Penetrating wounds to the heart are, of course, usually lethal unless surgically repaired. Stab wounds to the right ventricle occasionally lead to hemopericardium without progressing to tamponade. The clinical result may be constrictive pericarditis, so surgery is recommended even if the patient presents in a stable condition.

Blunt trauma is a more frequent cause of cardiac injuries, particularly outside of the emergency room setting. This type of injury is quite frequent in motor vehicle accidents and may occur with any form of chest trauma. The most common injuries are myocardial contusions or hematomas. These may be asymptomatic (particularly in the setting of more severe injuries) or may present with chest pains of a nonspecific nature or, not uncommonly, with a pericardial component. A minority of patients will develop left or, less commonly, right ventricular aneurysm. Elevations of cardiac enzymes are frequent, and echocardiography may reveal an akinetic segment. Heart failure is uncommon if there are no associated cardiac or pericardial injuries, and conservative management is usually sufficient.

Severe trauma may also cause cardiac or valvular rupture. Cardiac rupture may involve any chamber, but survival is most likely if injury is to one of the atria or the right ventricle. Hemopericardium or pericardial tamponade is the usual clinical presentation, and surgery is almost always necessary. Mitral and aortic valve rupture may occur during severe blunt trauma - the former presumably if the impact occurs during systole and the latter if during diastole. Patients reach the hospital in shock or severe heart failure. Immediate surgical repair is essential. The same types of injuries may result in transection of the aorta, either at the level of the arch or distal to the takeoff of the left subclavian artery. Transthoracic and transesophageal echocardiography are the most helpful and immediately available diagnostic techniques.

Blunt trauma may also result in damage to the coronary arteries. Acute or subacute coronary thrombosis is the most common presentation. The clinical syndrome is one of acute myocardial infarction with attendant electrocardiographic, enzymatic, and contractile abnormalities. Emergent revascularization is sometimes feasible, either by the percutaneous route or by coronary artery bypass surgery. Left ventricular aneurysms are common outcomes of traumatic coronary occlusions. Coronary artery dissection or rupture may also occur in the setting of blunt cardiac trauma.

Harada H et al: Traumatic coronary artery dissection. Ann Thorac Surg 2002;74:236.

Lindstaedt M et al: Acute and long-term clinical significance of myocardial contusion following blunt thoracic trauma: results of a prospective study. J Trauma 2002;52:479.

Wall MJ Jr et al: Trauma to cardiac valves. Curr Opin Cardiol 2002;17:188.