A case of neurally mediated syncope induced by laughter successfully treated with combination of propranolol and midodrine.

A 69-year-old man had been suffering from recurrent syncope induced by laughter since the age of 58. His syncope was reproduced by head-up tilt testing with isoproterenol infusion and we concluded that his laughter-induced syncope was one type of neurally mediated syndrome (NMS). His daughter also had NMS and her syncope was treated with propranolol. Propranolol and midodrine hydrochloride, an alpha(1)-adrenergic stimulant, were effective at preventing his laughter-induced syncope. This is a case report of laughter-induced syncope with a familial predisposition successfully treated with the combination of the nonselective beta-blocker propranolol and the alpha(1)-stimulator midodrine.