This study sought to clarify major complications associated with acetylchol
ine testing. Serious major complications, such as sustained ventricular tac
hycardia, shock, and cardiac tamponade were determined in 4 of 715 patients
(0.56%), but no cases of death or irreversible complications occurred. The
spasm provocation test using acetylcholine should be performed carefully,
although it is considered a safe and reliable method.