Teaching Case

A 64-year-old female motorist involved in a high-speed motor vehicle accident presents with hypoxia and hypotension.

CT chest and abdomen demonstrated significant left-sided chest and abdominal blunt trauma necessitating an emergency thoracotomy and laparotomy. A pleural drain was inserted for a large left pneumothorax. Complete rupture and fragmentation of the pericardium without myocardial contusion was identified intra-operatively. A post-operative chest radiograph in the intensive care unit showed a prominent cardiac silhouette with rotation of the cardiac axis. Subsequent CT chest one day post-operatively confirmed a change in cardiac axis with complete herniation of the heart into the left pleural cavity.

Blunt traumatic pericardial rupture is rare, occurring in less than 0.5% of blunt trauma victims [1]. The left pleuropericardium is more commonly involved than the right side or the diaphragmatic pericardium [2]. Haemodynamic instability may arise from small or intermediate sized tears secondary to cardiac strangulation or torsion of the heart around the great vessels. Large left-sided tears, as in our case, may be asymptomatic and may not require further surgical intervention. Pre-operative diagnosis of blunt traumatic pericardial rupture is challenging and requires a high level of clinical suspicion. Imaging findings on chest radiography include a shift of the cardiac silhouette to the right or left, pneumopericardium, bowel loops within the pericardial sac and herniation and rotation of the heart into either pleural cavity [3, 4]. CT is more sensitive than chest radiography in identifying these signs, with the diagnosis almost always made during surgical exploration. Once diagnosed, concomitant cardiac injury and great vessel injury should be excluded.