Head-up tilt test without intravascular cannulation in children and adolescents

Previous studies of head-up tilt test have shown that testing at high degre es lacks specificity in children. We suspected that the high false positive rate might be related to the intravascular catheter and other maneuvers in corporated in the test and therefore studied the sensitivity and specificit y of standing and HUT at 80 degrees without any invasive procedure and othe r maneuvers in children and adolescents. Twenty three patients (11.8 +/-2.7 years) with recurrent typical neurally mediated syncope and 35 normal cont rol children (11.6 +/-3.0 years) underwent motionless standing for 15 min a nd tilting to 80 degrees for 30 min. Continuous finger arterial pressure mo nitoring and ECG were performed during the test. Eight (35%) of the 23 pati ents developed symptoms of near syncope during motionless standing. Thirtee n (57%) of them had positive results at 80 degrees tilting for 30 min. The symptoms of syncope were not always corresponding to excessive haemodynamic changes. None of the controls developed any symptoms or excessive hemodyna mic changes. Without intravascular instrumentation and other autonomic mane uvers, active motionless standing or HUT at 80 degrees for 30 min is highly specific but of limited sensitivity for the investigation of vasovagal syn cope. (C) 2001 Elsevier Science Ireland Ltd. All rights reserved.