Trauma is the leading cause of death and disability among young people in the United States.1-3 Cardiac and great vessel injuries are common contributors to the morbidity and mortality of severely injured patients.4 Injury to the heart and thoracic aorta can be broadly divided into penetrating or blunt mechanisms.
Penetrating Cardiac Injuries
Penetrating injury to the heart must be suspected with any missile or knife wound to the thorax or upper abdomen. The anteriorly positioned right ventricle is most frequently injured followed by the left ventricle and right atrium.5 Other potentially injured structures include the interatrial or interventricular septum, coronary arteries, valves, subvalvular apparatus, and conduction system.6 Low-velocity injuries, such as stab wounds, produce damage commensurate to the structure penetrated and size of the defect. High-velocity missiles produce injury beyond the region of myocardial penetration secondary to concussive effects and are more frequently lethal.7-10
The primary manifestations of cardiac penetration are hemorrhage and tamponade. Valve or coronary injury may, of course, produce acute valvular incompetence or myocardial infarction. Stab victims often present with tamponade when clot and surrounding pericardial fat partially seal the pericardial defect. Injuries to the left ventricle more commonly result in overt hemorrhage. Patients presenting with tamponade may have a survival advantage, with mortality rates as low as 8% in experienced trauma centers.7 Early diagnosis is critical to survival, and this is only possible with a high index of suspicion, bearing in mind that patients with potentially fatal wounds can be stable at presentation. Echocardiography can confirm the diagnosis of cardiac injury, but the lack of an effusion does not disprove injury.11 The diagnostic gold standard, short of exploration, is a subxiphoid window.
Management of penetrating wounds to the heart depends on the stability of the patient. If the patient presents with a recent loss of vital signs or in a moribund state, a left anterior thoracotomy performed in the emergency department is potentially lifesaving. Emergent thoracotomy may salvage as many as 20% of unstable or pulseless patients who have isolated penetrating trauma to the heart, but results are less favorable with missile wounds.12,13 Most cardiac wounds can be repaired through a left thoracotomy. Additionally, the thoracic aorta can be compressed or clamped to improve cerebral and cardiac perfusion while volume is restored. More stable patients are transported to the operating room, where a median sternotomy is the preferred approach. A sternotomy allows adequate exposure of all cardiac structures and permits rapid institution of cardiopulmonary bypass when required. Most injuries are repaired with simple pledgeted sutures using finger control to stop bleeding once identified. Coronary artery injuries are common, and the surgeon must use his or her judgment regarding coronary artery bypass versus ligation. An effort should be made to bypass large epicardial vessels, whereas smaller terminal branches or side branches can be ligated. The principal objective is to relieve tamponade and ...