Head-up tilt testing potentiated with oral nitroglycerin: a randomized trial of the contribution of a drug-free phase and a nitroglycerin phase in the diagnosis of neurally mediated syncope.

Head-up tilt testing potentiated with oral nitroglycerin: a randomized trial of the contribution of a drug-free phase and a nitroglycerin phase in the diagnosis of neurally mediated syncope.