Autonomic Alterations After Pulmonary Vein Isolation or Antiarrhythmic Drug Therapy

Area of Science:

• Cardiology
• Autonomic Nervous System Research
• Medical Device Technology

Background:

• The long-term effects of catheter ablation versus antiarrhythmic drugs on autonomic function are not well understood.
• Previous studies relied on intermittent monitoring, lacking comparative data.

Purpose of the Study:

• To compare the long-term impact of cryoballoon ablation versus antiarrhythmic drug therapy on autonomic parameters.
• To evaluate changes in heart rate variability (HRV), daytime heart rate (DHR), and nighttime heart rate (NHR).

Main Methods:

• 303 treatment-naïve paroxysmal atrial fibrillation patients from the EARLY-AF trial were randomized.
• Intervention groups: cryoballoon ablation (154) or antiarrhythmic drug therapy (149).
• Continuous autonomic monitoring via implantable cardiac monitor (ICM) for HRV, DHR, and NHR.

Main Results:

• No baseline differences in HRV, DHR, or NHR between groups.
• Ablation group showed reduced HRV and increased DHR/NHR compared to drug therapy over median 1,143 days.
• Differences persisted up to 24-36 months; autonomic changes associated with arrhythmia recurrence.

Conclusions:

• Cryoballoon pulmonary vein isolation causes sustained autonomic parameter changes compared to antiarrhythmic drugs.
• These findings highlight significant, lasting autonomic effects of ablation therapy.