Arrhythmias & electrophysiologyMechanistic study
Temporal relationship between haemodynamic changes and activation of closed-loop stimulation during a tilt-induced vasovagal syncope
- Mechanistic study
Authors' conclusion
The reproducibility of a vasovagal reflex was high. High-rate CLS pacing was observed early during the pre-syncopal phase in most patients and persisted, although attenuated, at the time of maximum vasovagal effect.
Study context
- Population
- Patients with asystolic VVS and a dual-chamber closed-loop stimulation (CLS) pacemaker, tilt test 3.9 years after implantation17 analysed
- Participants
- Twenty patients
- Comparison
- CLS pacing vs No CLS pacing
- CLS pacingn = 14
- No CLS pacingn = 3
Main finding
As reported in the abstract
Haemodynamics and timing of CLS pacing during tilt-induced vasovagal reflex
- CLS pacing emerged in the pre-syncopal phase
- 14 of the remaining 17
- Intrinsic HR at CLS onset (mean ± SD)
- 88 ± 12 b.p.m.
- Systolic blood pressure (SBP) at CLS onset (mean ± SD)
- 108 ± 19 mmHg
- CLS pacing rate after rapid increase (mean ± SD)
- 105 ± 14 b.p.m.
- Time to peak CLS rate, median (IQR)
- 0.1 min (0.1-0.7 min)
- SBP at peak CLS rate (mean ± SD)
- 99 ± 21 mmHg
- SBP at maximum vasovagal effect (mean ± SD)
- 63 ± 17 mmHg
- CLS rate at maximum vasovagal effect (mean ± SD)
- 95 ± 13 b.p.m.
- Onset of CLS pacing before syncope or lowest SBP (IQR)
- 1.7 min (1.5-3.4)
- Total duration of CLS pacing (IQR)
- 5.0 min (3.3-8.3)
- No CLS pacing: SBP baseline to maximum vasovagal effect (mean ± SD)
- 142 ± 22 mmHg to 69 ± 4 mmHg
- No CLS pacing: HR, no significant increase (mean ± SD)
- 59 ± 1 b.p.m.
Original publication
Temporal relationship between haemodynamic changes and activation of closed-loop stimulation during a tilt-induced vasovagal syncope. Europace. Published 10 February 2024. doi:10.1093/europace/euae045
Summarised from the published abstract; every number is checked against it