enetrating chest injuries involving the heart and great vessels are associated with high morbidity and require rapid determination of the anatomic compartment(s) involved to guide urgent therapy. The decision to explore the mediastinum and cardiac structures is often based on clinical signs, but cardiac penetration may occur without acute hemodynamic compromise or hemopericardium. We describe a case of a hemodynamically stable patient who presented to the emergency department (ED) after projectile lawn mower injury, describe the utility of computed tomography in this context, and review the literature regarding these wounds.
CASE REPORTA 67-year-old ambulatory man with a medical history of chronic obstructive pulmonary disease and no known surgical history presented to the ED complaining of anterior right chest wound suffered while mowing the lawn. The patient described a fragment of chicken wire fence striking his chest, but claimed it fell out when he removed his shirt. There was no loss of consciousness, and he was alert and oriented ϫ3 in the ED. Physical examination revealed equal breath sounds bilaterally with no peripheral cyanosis, pericardial rub, or jugular venous distention. Blood pressure was 145/89, pulse was 62, and respiratory rate was 18. Oxygen saturation was 100% on room air, and electrocardiogram revealed normal sinus rhythm with first degree atrioventricular block and prolonged QT interval. Erect posteroanterior (PA) and lateral chest radiographs demonstrated a linear high attenuation foreign body overlying the anterior cardiac silhouette (Fig. 1). Transesophageal echocardiography performed in the ED revealed normal left ventral function with no evidence of hemopericardium or intracardiac shunt, but was unable to locate the foreign body.Urgent computed tomography (CT) was then performed and accurately depicted soft tissue stranding in a missile tract that extended inferiorly, posteriorly and leftward from the right parasternal chest wall wound (Fig. 2). The foreign body was readily identified as linear and metallic, lying between the cardiac base and the anterior aspect of the distal esophagus within the mediastinum (Fig. 3). Its position had clearly changed with assumption of supine position for CT (Fig. 1), and a determination of "tumbling" dependent pericardial missile was made. There was no evidence of hemopneumothorax or hemopericardium, and no indication the missile had entered the abdominal cavity.