Acute aortic dissection occurring during the butterfly stroke in a 12-year-old boy.

A 12-year-old boy had severe chest and back pain of sudden onset while practicing the butterfly stroke in a swimming class. Computed tomography revealed an intimal flap in the descending thoracic aorta with massive right hemothorax. A ruptured type B acute aortic dissection was diagnosed, and then he collapsed. We totally replaced the descending aorta with a woven polyester prosthetic graft during deep hypothermic circulatory arrest. Hemostasis was achieved, but consciousness was not regained after operation, and multiple organ failure occurred. He died on the fifth postoperative day. He and his family had no history of cardiovascular disease. It seems that the swimming provoked a severe Valsalva maneuver, raising blood pressure acutely and thereby leading to dissection. This is then analogous to the propensity for dissection during intense isometic exercise such as weightlifting.