Acceleration stress-induced Wolff-Parkinson-White Syndrome with marked ST-segment depression

Exercise can affect preexcitation in several ways. The possible presence of catecholamine-sensitive bypass, stimulated during periods of high stress, was recently reported. In addition to a direct effect on the preexcitation, when the preexcitation pattern exists, exercise-induced ST-segment changes may occur which preclude stress testing for coronary artery disease detection. Current high-performance fighter pilots, flying new generation aircraft, are under severe stress during aerial combat maneuvering when they are exposed to high sustained +Gz (head-to-foot) acceleration stress. We report the occurrence of a +Gz acceleration-induced episode of preexcitation with marked ST-segment depression in a healthy asymptomatic aircrewman. Autonomic imbalance, with high catecholamine levels developed during +Gz stress, may be the etiology of this preexcitation episode.