Cardiac tamponade complicating proximal aortic dissection. Is pericardiocentesis harmful?

BACKGROUND: Cardiac tamponade frequently complicates acute proximal aortic dissection and is one of the most common causes of death from aortic dissection. Well-defined strategies for the management of acute aortic dissection now exist; however, little is known about how best to manage the hemopericardium that may complicate it.

METHODS AND RESULTS: Using a computer-based review, we retrospectively identified 10 patients presenting to our hospital over a 13-year period who were diagnosed with both aortic dissection and cardiac tamponade. All 10 had proximal dissections. Three of the 10 presented as the sudden onset of fatal electromechanical dissociation, 6 presented with hypotension, and 1 was normotensive on presentation. Of the 7 hypotensive or normotensive patients diagnosed with cardiac tamponade, 4 underwent successful pericardiocentesis while awaiting surgery. At time intervals of 5 to 40 minutes after their pericardiocenteses, 3 of the 4 patients experienced sudden onset of electromechanical dissociation and death; the fourth patient survived and underwent surgical repair. Of the 3 hypotensive or normotensive patients who had either no pericardiocentesis or an unsuccessful pericardiocentesis, all 3 underwent successful surgical repair and survived.

CONCLUSIONS: In this study, patients with an aortic dissection complicated by cardiac tamponade have an early mortality of 60%. While 3 of the 10 died from electromechanical dissociation immediately upon presentation, the 3 other deaths all occurred shortly after successful pericardiocentesis, a procedure undertaken to stabilize them. While the number of patients in this series is small, the observations do raise the possibility that in patients with cardiac tamponade complicating aortic dissection pericardiocentesis could be harmful rather than beneficial. Possible mechanisms for why the performance of pericardiocentesis might destabilize such patients are proposed.