The benefit of closed loop stimulation in patients with cardioinhibitory vasovagal syncope confirmed by head-up tilt table testing: a systematic review and meta-analysis

J Interv Card Electrophysiol. 2019 Jun;55(1):105-113. doi: 10.1007/s10840-019-00531-0. Epub 2019 Mar 12.


Purpose: A proportion of patients with vasovagal syncope (VVS) experience recurrence despite appropriate management. Closed loop stimulation (CLS) pacing is a promising treatment for a subgroup of patients with cardioinhibitory response on head-up tilt table test (HUTT). Nonetheless, its efficacy remains uncertain. We sought to assess the efficacy of CLS pacing in patients with cardioinhibitory VVS.

Methods: We searched PubMed, Google Scholar, and the Cochrane Central Register of controlled trials for relevant studies (last search date April 23, 2018). Data were pooled using the Mantel-Haenszel fixed-effects model. For cohort studies, we used a Freeman-Tukey transformation to calculate the weighted summary proportion. Primary outcomes are syncope and presyncope.

Results: Eight studies were included in the final analyses (two single-blinded and one double-blinded RCT, two prospective observational studies, and three retrospective observational studies). Two hundred ninety-one patients included, with an average age of 57 years. Quality of evidence is moderate. Use of CLS pacing was associated with reduced risk of syncope (OR 0.08; 95% CI 0.03-0.18; I2 32%) and presyncope (OR 0.34; 95% CI 0.18-0.63; I2 0.00%). Using proportion meta-analysis, the summary estimate of the proportion of cases that developed syncope during CLS pacing was similar between RCTs and prospective studies (3.2% and 3.1%), respectively. This is much lower than the rate of recurrence in the control arm of RCTs at 33.7%. Sensitivity analyses yielded similar results.

Conclusion: CLS pacing is beneficial for patients with recurrent vasovagal syncope who demonstrate a cardioinhibitory response on HUTT.

Keywords: Closed loop stimulation; Pacemaker; Syncope; Vasovagal.

Publication types

  • Meta-Analysis
  • Systematic Review

MeSH terms

  • Cardiac Pacing, Artificial / methods*
  • Humans
  • Recurrence
  • Syncope, Vasovagal / diagnosis*
  • Syncope, Vasovagal / therapy*
  • Tilt-Table Test*