Home orthostatic training in vasovagal syncope modifies autonomic tone: results of a randomized, placebo-controlled pilot study
Europace
Home orthostatic training in vasovagal syncope modifies autonomic tone: results of a randomized, placebo-controlled pilot study
Maw Pin Tan 2
Julia L. Newton 1 2
Tom J. Chadwick 0
Janine C. Gray 1
Samiran Nath 3
Steve W. Parry 1 2
0 Institute of Health and Society, Newcastle University , Newcastle upon Tyne , UK
1 Falls and Syncope Service, Royal Victoria Infirmary , Queen Victoria Road, Newcastle upon Tyne NE1 4LP , UK
2 Institute for Ageing and Health, Newcastle University , Newcastle upon Tyne , UK
3 Department of Cardiology, North Tyneside General Hospital , North Shields , UK
Aims To detect possible autonomic changes due to home orthostatic training (HOT) and to assess the feasibility of a larger, placebo-controlled study of HOT in vasovagal syncope (VVS). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Methods Twenty-two consecutive patients, aged 18 - 85, diagnosed with VVS following a positive head-up tilt-table test were and results randomized to 40 min of HOT (n ¼ 12) or 10 min of sham training (n ¼ 10) daily for 6 months. Baroreflex sensitivity (BRS) and heart rate variability (HRV) were measured at weeks 0, 1, 4, and 24. Symptom response was assessed by event diaries. Home orthostatic training resulted in increases in up and down slope BRS at week 4 (elog difference ¼ 1.59, 95% CI ¼ 0.84 - 3.03 and 1.79, 95% CI ¼ 1.00 - 3.22) and week 24 (elog difference ¼ 1.75, 95% CI ¼ 1.01 - 3.06 and 1.53, 95% CI ¼ 0.66 - 2.68) compared with placebo. Relative improvements in low- and highfrequency HRV were also observed in the HOT group compared with placebo at week 4 (elog difference ¼ 3.22, 95% CI ¼ 1.06 - 9.86 and 3.19, 95% CI ¼ 1.03 - 10.59) and week 24 (elog difference ¼ 2.11, 95% CI ¼ 0.72 - 6.17 and 2.13, 95% CI ¼ 0.52 - 8.79). Fifty percentage of HOT subjects and 20% of control subjects were syncope-free at 6 months. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Conclusion This was the first placebo-controlled study in orthostatic training which has demonstrated that such a study is indeed feasible. An enhancement in overall autonomic tone is observed with HOT in tandem with a non-significant trend in symptom improvement. A larger, adequately powered, randomized controlled trial of tilt-training is now needed. - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Introduction
Vasovagal syncope (VVS) is the commonest cause of transient loss
of consciousness, accounting for 40% of syncopal episodes
presenting to the emergency department.1 It was previously
assumed to be rare in older adults but has been diagnosed with
increasing frequency since the head-up tilt-table (HUT) test was
described in 1986.2,3 Although VVS in most patients either
occurs infrequently or responds well to conservative measures,
many patients continue to have persistent symptoms. The
treatment options for the latter group of individuals are currently
limited, with the recent randomized controlled trials involving
beta-adrenergic receptor blockers4 and permanent cardiac
pacemakers5,6 being negative.
Tilt-training or orthostatic training has been advocated as a
possible effective treatment for VVS. There have been a handful
of small, uncontrolled studies demonstrating promising results,
though there were large variations in methodologies between
the studies which included both formal tilt-table training and
informal home orthostatic training (HOT).7 – 12 The randomized
controlled studies published so far did not show any beneficial
effects for tilt-training probably due to poor compliance.13 – 16 In
addition, control subjects in these studies were randomized to
conventional treatment, not placebo. The haemodynamic effects
and mechanisms of action of tilt-training have never been studied
in the context of a randomized controlled trial. Despite this lack of
good-quality evidence, tilt-training is recommended by consensus
guidelines as a treatment for VVS.3,17,18
Our aim was to conduct the first randomized placebo
(sham)controlled study of HOT in VVS. The objectives of this study
were: first, to determine the changes in autonomic function in
response t (...truncated)