A single-center randomized controlled trial observing the safety and efficacy of modified step-up graded Valsalva manoeuver in patients with vasovagal syncope
January
A single-center randomized controlled trial observing the safety and efficacy of modified step-up graded Valsalva manoeuver in patients with vasovagal syncope
Li He 0 1 2
Lan Wang 0 2
Lun Li 0 1 2
Xiaoyan Liu 0 1 2
Yijun Yu 0 1 2
Xiaoyun Zeng 0 2
Huanhuan Li 0 1 2
Ye Gu 0 1 2
0 Science Foundation of Hubei Province, China (Grant No. 2013CFB364) and the Foundation of Wuhan , Hubei Province, China, Grant No. WX15A07
1 Department of Cardiology, Puai Hospital, Huazhong University of Science and Technology , Wuhan, Hubei province, China , 2 Department of Neurology, Puai Hospital, Huazhong University of Science and Technology , Wuhan, Hubei province , China
2 Editor: Moshe Swissa, Kaplan Medical Center , ISRAEL
Non-pharmacological therapies, especially the physical maneuvers, are viewed as important and promising strategies for reducing syncope recurrences in vasovagal syncope (VVS) patients. We observed the efficacy of a modified Valsalva maneuver (MVM) in VVS patients. 72 VVS patients with syncope history and positive head-up tilt table testing (HUTT) results were randomly divided into conventional treatment group (NVM group, n = 36) and conventional treatment plus standard MVM for 30 days group (MVM group, n = 36). Incidence of recurrent syncope after 12 months (6.5% vs. 41.2%, P<0.01) and rate of positive HUTT after 30 days (9.7% vs.79.4%, P<0.01) were significantly lower in MVM group than in NVM group. HRV results showed that low frequency (LF), LF/ high frequency (HF), standard deviation of NN intervals (SDNN) and standard deviation of all 5-min average NN intervals (SDANN) values were significantly lower in the NVM and MVM groups than in the control group at baseline. After 30 days treatment, LF, LF/HF, SDNN, SDANN values were significantly higher compared to baseline in MVM group. Results of Cox proportional hazard model showed that higher SDNN and SDANN values at 30 days after intervention were protective factors, while positive HUTT at 30 days after intervention was risk factor for recurrent syncope. Our results indicate that 30 days MVM intervention could effectively reduce the incidence of recurrent syncope up to 12 months in VVS patients, possibly through improving sympathetic function of VVS patients.
-
Data Availability Statement: All relevant data are
within the paper and its Supporting Information
files.
Competing interests: The authors have declared
that no competing interests exist.
Introduction
Vasovagal syncope (VVS) is a clinical syndrome resulting from systemic hypotension due to
transient global cerebral hypoperfusion, and characterized by rapid onset, short duration and
spontaneous complete recovery [
1
]. There are three types of VVS: vasodepressor syncope,
cardio-inhibitory syncope and mixed syncope. Although not directly responsible for increased
mortality, VVS could have a tremendous deleterious impact on the daily quality of life of
patients in terms of physical symptoms and injury as well as psychological impact from living
in fear of the next syncopal episode [2±4].
Therapeutic options for VVS remain challenging and far from optimal now [5±7].
Nowadays, following strategies were attempted to reduce syncope recurrences in VVS patients with
variable efficacies: 1) physical techniques to improve orthostatic tolerance; 2) pharmacologic
interventions to prevent depletion of intravascular volume and/or enhance arterial and venous
tone; 3) cardiac pacing to avert bradycardia [
4,8
]; and 4) anatomically guided endocardial
catheter ablation of ganglionated plexi in left atrium [9]. Among above mentioned therapy options,
non-pharmacological therapies, especially the physical maneuvers, are viewed as important and
promising strategies for reducing the syncope recurrences [
5
]. In a previous study, Krediet and
colleagues demonstrated beneficial effects of leg crossing and muscle tensing in VVS patients
[
10
]. Brignole et al. also reported a comparable effect of isometric arm counterpressure
maneuvers to abort impending VVS [
11
]. In another study, van Dijk et al. showed that physical
counterpressure maneuvers were effective in preventing vasovagal syncope [
12
].
Head-up tilt testing (HUTT) is a usual medical procedure to diagnose VVS and to define
potential causes of syncope. Previous report showed that Valsalva maneuver (VM) could
induce syncope in volunteer subjects [
13
], and the abrupt reduction in mean arterial blood
pressure and subsequent reduction of cerebral perfusion during phase III of VM might be
responsible for VM-induced syncope [
14
]. Based on these reports, we once asked patients with
suspected syncope to perform the classic VM for several times at the beginning and during
HUTT in an attempt to increase the positive rate of HUTT in these patients. To our surprise,
post VM, the HUTT result became negative in 4 out of 8 patients with previous positive
HUTT results. This finding encouraged us to test if VM could have therapeutic effects in
sy (...truncated)