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Pacing for neurally mediated syncope: is placebo powerless?
1Department of Cardiology, Ospedali del Tigullio, Via don Bobbio, 16033 Lavagna, Italy. mbrignole@ASL4.liguria.it
Summary
Placebo pacing therapy is ineffective for neurally mediated syncope. Active cardiac pacing showed a lower syncope recurrence rate compared to placebo or no treatment in controlled trials.
Area of Science:
- Cardiology
- Clinical Trials
- Neurally Mediated Syncope
Background:
- Recent trials question cardiac pacing efficacy for neurally mediated syncope.
- A significant placebo effect is suspected in syncope management.
Purpose of the Study:
- To quantify the therapeutic effect of placebo pacing therapy.
- To compare syncope recurrence rates between placebo and no treatment.
Main Methods:
- Meta-analysis of controlled trials for drug or pacing therapy.
- Comparison of syncope recurrence in patients receiving placebo versus no treatment.
- Analysis of recurrence rates for active cardiac pacing.
Main Results:
- Syncope recurred in 38% of patients receiving placebo (252 patients, 5 trials).
- Syncope recurred in 34% of patients receiving no treatment (881 patients, 8 trials).
- Active cardiac pacing showed a 15% recurrence rate (203 patients, 6 trials).
Conclusions:
- Placebo therapy is not effective for neurally mediated syncope.
- Patient selection criteria, particularly the cardioinhibitory reflex, may explain trial outcome variations.
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