Vasovagal Response Induced by a Low Dose of Isoproterenol Infusion Before Tilting-up

Abstract

A 56 year-old man was referred to hospital for evaluation of syncopal episodes. During head-up tilt testing, his symptom was reproduced, associated with bradycardia and hypotension, by a low dose of isoproterenol (0.02 μg · kg ^-1 · min^-1) infusion in the supine position before tilting-up. Isoproterenol infusion can provoke a vasovagal response without tilting. Careful observation of the patient's hemodynamics is mandatory not only during tilting, but also in the supine position before tilting-up. (Circ J 2004; 68: 876 - 877)