A case report: hemothorax caused by rupture of the left atrial appendage.

Cardiac rupture is defined as a full-thickness myocardial tear; this injury after blunt chest trauma is rare, and is associated with high mortality. Blunt cardiac rupture typically presents with either cardiac tamponade or massive hemothorax, and is often unrecognized in the context of blunt chest trauma. It is a little known fact that pericardial effusions can decrease due to pericardial lacerations. Hence, cardiac rupture with pericardial lacerations may be easily overlooked especially by chest surgeons. We herein report a case of hemothorax caused by rupture of the left atrial appendage. An 80-year-old male was involved in a motor vehicle crash. We made the diagnosis of hemothorax on the basis of bloody thoracic effusion and left pleural effusion on computed tomography (CT). CT also showed small pericardial effusion in amount and non-displaced rib fractures. We made a tentative diagnosis of intercostal artery injury with rib fractures, we performed left thoracotomy. However, in the operating room, we recognized that cardiac rupture led to massive hemothorax, and that hemothorax was not associated with intercostal artery injury. We repaired left atrial appendage rupture, and his postoperative course was uneventful. Cardiac rupture can present as slight pericardial effusion with hemothorax. On the basis of this case, we propose that cardiac rupture should be considered at the time of hemothorax examination with careful attention to pericardial effusions.