Effects of low-dose metoprolol succinate sustained-release tablets on patients with paroxysmal atrial fibrillation undergoing circumferential pulmonary vein isolation: a retrospective cohort study.

BACKGROUND: The atria, particularly those near the pulmonary vein ostium, have numerous autonomic neural plexuses. Circumferential pulmonary vein isolation (CPVI) can reduce heart rate variability (HRV) parameters. Studies have suggested that continuing antiarrhythmic drugs (AADs) for 1year post-CPVI can reduce the recurrence of atrial arrhythmias within the year. However, the arrhythmogenic risk associated with AADs is notable. Currently, there is a shortage of adequate studies on the effectiveness and safety of using AADs following CPVI. This exploratory study evaluated the impact of low-dose sustained-release metoprolol succinate on Holter in individuals with paroxysmal atrial fibrillation (PAF) after CPVI.

METHODS: Patients with PAF who underwent initialCPVI at Shaoxing People's Hospital between September 2022 and January 2024 were retrospectively enrolledusing the electronic medical record system. Patients underwent 24-h Holter monitoring before the procedureand at 1 - 3, 6, 12, and 18 months afterthe procedure. The participantswere separated into medication and non-medication groupsaccording to their heart rate and clinical experience.

RESULTS: Overall, 67 patients completed the 24-h Holter monitoring, with 33 receiving low-dose metoprolol succinate (23.75 mg/day)(medication group) and 34 not receiving AADs (non-medication group). No significant differences were observed in HRV parameters and arrhythmia data between the two groups or across the different time points.

CONCLUSIONS: Oral low-dose sustained-release metoprolol succinate tablets may have no significant short-term effects on HRV parameters or arrhythmia data in patients with PAF post-CPVI. CPVI can cause autonomic dysfunction, and HRV parameters were gradually restored to normal 3months post-procedure.