A novel tilt table testing protocol for investigating patients suspected to have neurally mediated syncope.

We have observed that a series of 3 Valsalva maneuvers performed at 1-minute intervals between the 15th and 18th minute of a drug-free tilt table test resulted in intense presyncope and hypotension in a 32 yr old male with micturition syncope. In contrast, five apparently healthy subjects tolerated a 70 degree head-up tilt table test for 45 min with five Valsalva maneuvers incorporated into the testing protocol. Thus, we hypothesize that the use of a series of Valsalva maneuvers during a drug free head-up tilt table test might improve the diagnostic yield without compromising test specificity in patients suspected to have neurally mediated syncope.