Reproducibility of asystole during head-up tilt testing in patients with neurally mediated syncope

Abstract

Tilt induced prolonged asystole has been considered to identify a distinct subgroup of patients with neurally mediated syncope and management including permanent pacemaker implantation has been suggested. To evaluate the reproducibility of asystolic response during head-up tilt testing (HUT), 33 patients with neurally mediated syncope and asystolic response (≥3 seconds) during HUT prospectively underwent two consecutive tests 13 ± 15 days apart. On repeat tilt testing asystole was reproduced in 12 patients (36%), while 8 patients still had a positive HUT, but without asystole. Remarkably, 13 patients (40%) had a negative repeat HUT. Among 12 patients with asystole on both HUTs there was no significant difference in duration of asystole (14 371 ± 11 430 ms vs 13 707 ± 10 470 ms, P=ns) and time to syncope (36 ± 20 min vs 37 ± 20 min, P=ns) during initial and repeat HUTs. In conclusion, asystole during tilt testing does not seem to be a reproducible response. © 2002 The European Society of Cardiology. Published by Elsevier Science Ltd. All rights reserved.