A systematic review on recurrent cardioinhibitory vasovagal syncope: Does pacing therapy break the fall?

Abstract

Vasovagal reflex is the most common cause of syncope. Pacemaker with rate drop response (RDR) or closed‐loop stimulation (CLS) anti‐syncope algorithms have been studied in recurrent vasovagal syncope (VVS), with conflicting results. We aim to investigate the role of pacemaker therapy and anti‐syncope pacing mode in cardioinhibitory recurrent VVS. MEDLINE, Cochrane Library and registered clinical trials were searched for single or double‐blind randomized controlled trials on pacing as a treatment for recurrent VVS. Five studies were eligible, overall enrolling 228 patients. After pooling data from all trials, pacemaker therapy showed a 63% reduction in syncope recurrence compared to control [Risk Ratio (RR): 0.37; 95% CI: 0.14‐0.98; I2 = 67%)]. Subgroup analyses suggested that the effect was greater in single‐blind studies (RR: 0.07; 95% CI: 0.01‐0.52, I2 = 0%). When comparing pacing algorithms, the results from RDR versus no pacing trials (n = 2) did not show a significant reduction in syncope recurrence (RR: 0.73; 95% CI: 0.25‐2.16, I2 60 = 75%). In contrast, the data from the CLS versus standard pacing trials (n = 3) evidenced a statistically meaningful reduction in syncopal burden (RR: 0.18; 95% CI: 0.07‐0.47, I2 = 0%). It is unclear whether pacemaker therapy reduces syncopal burden in cardioinhibitory recurrent VVS. However, our results suggest effectiveness of CLS pacing mode.

Cardiac pacing in vasovagal syncope in the light of the latest recommendations

“…In a metaanalysis that compared conventional pacing with CLS-based pacing in patients with recurrent VVS (6 studies, 224 patients), a clear superiority of CLSbased pacing was shown [24]. Similar results were obtained when CLS-based pacing was compared with RDR--based pacing (a meta-analysis of 5 studies, n = 228) [25].…”

Management strategies for vasovagal syncope

“…34 A systematic review, which did not include BioSync CLS, showed that CLS pacing mode significantly reduced syncope recurrence in cardioinhibitory VVS while rate drop response (RDR) did not. 35 The evidence so far of the pacing therapy in VVS has bought forward multiple issues. There is a significant psychological/placebo effect of pacemaker implantation.…”

Normal baseline cardiac autonomic function and increased pupillary parasympathetic tone in patients with vasovagal syncope

“…Overall, syncope accounts for 3%–5% of emergency department visits, with a hospitalization rate of about 40% and an average stay of 5.5 days (da Silva, 2014). Loss of consciousness in VVS occurs as a consequence of an inappropriate vasodepressor (hypotensive) or a cardioinhibitory (bradycardic) response, or a combination of these (Brignole et al, 2018; da Cunha et al, 2019). Notably, the mechanism of the vasovagal reflex is not completely understood (Alboni & Alboni, 2017).…”