Recurrent Syncope in Patients With Reflex Syncope Treated With Dual‐Chamber Pacemakers: Short‐Term Associated Factors—A Single‐Center Retrospective Study

Background Dual‐chamber pacemakers equipped with anti‐reflex syncope algorithms are an established therapeutic option for preventing recurrent syncope in selected patients with reflex syncope. However, their efficacy in patients under 40 years old and in non‐type 2B syncope remains uncertain and clinical predictors of recurrent syncope post‐implantation are not well established. Objective To identify clinical factors associated with early recurrence of syncope in patients with reflex syncope who received dual‐chamber pacemakers with anti‐syncope functionality. Methods This retrospective cohort study included 117 patients (65% female) with reflex syncope confirmed by a positive tilt‐table test. All received dual‐chamber pacemakers. The primary endpoint was syncope recurrence within 6 months. Results Among 117 paced patients, 15 (12.8%) had recurrent syncope by 6 months. In the reduced Cox model, all three prespecified variables independently predicted recurrence: female sex (HR: 5.386; 95% CI: 1.689–17.175; p = 0.004), systolic blood pressure differential between the end of the passive phase and the syncope onset (HR: 1.036; 95% CI: 1.008–1.064; p = 0.011), number of prior syncope episodes (HR: 2.950; 95% CI: 1.565–5.561; p = 0.001). ROC‐based cutoffs supported descriptive separation (e.g., ≥ 2.5 prior episodes; ΔSBP ≥ 87.5 mmHg; asystole ≥ 13.5 s), but continuous coding was used for modeling to avoid information loss. Conclusion Within 6 months of dual‐chamber pacemaker implantation, recurrent syncope was more likely in female sex, a larger systolic blood pressure differential between the end of the passive phase and syncope onset, and greater pre‐implantation syncope burdens.