Abstract 2878: Modulation of Autonomic Function in Patients Undergoing Circumferential or Segmental Pulmonary Vein Ablation for Paroxysmal Atrial Fibrillation
Background: Circumferential and segmental pulmonary vein ablation (CPVA and SPVA) are two established interventional treatment strategies for ablation of atrial fibrillation. Both techniques require the application of radiofrequency current at anatomical sites that are close to parasympathetic ganglia. Vagal activity is known to be strongly involved in the triggering and maintenance of atrial fibrillation. This study was designed to analyse the acute and long term effect of CPVA and SPVA on vagal autonomic function.
Methods and Results: One hundred patients with highly symptomatic atrial fibrillation were randomly assigned to undergo either CPVA or SPVA. Twenty-four hour Holter recordings were recorded at baseline and up to twelve months after ablation. Vagal autonomic function was assessed by deceleration capacity (DC) of heart rate, a novel autonomic risk predictor, as well as by standard measures of heart rate variability (HRV). In the CPVA group, DC decreased from 5.7±2.1 ms at baseline to 3.3±1.8 ms directly after ablation (p<0.00001, see Figure⇓). Impairment of DC was present up to one year after ablation (p<0.003). In the SPVA group, DC decreased from 5.8±2.0 ms at baseline to 3.4±1.2 ms directly after ablation (p<0.00001). However, DC returned to baseline one month after ablation and remained stable up to one year after ablation (p<0.05 for differences between CPVA and SPVA from 1 month to one year). Similar (but less significant) changes were found for standard variables of HRV.
Conclusions: CPVA and SPVA induce an immediate decrease of vagal tone. However, while this decrease is only transient with SPVA, it persists with CPVA for at least one year.