Assessment of Cardiac Autonomic Dysfunction After Pulmonary Vein Isolation and Its Impact on Success of Paroxysmal Atrial Fibrillation Ablation.

Background: Atrial-fibrillation is the most prevalent cardiac arrhythmia and a significant public health issue. Recently,radiofrequency current ablation and cryoballoon ablation are frequently used for rhythm control in symptomatic paroxysmal AF patients who are resistant to anti-arrhythmic drugs or even as a firstline rhythm control strategy. Several studies have demonstrated an increase in heart rate and a decrease in heart rate variability after radiofrequency catheter ablation of atrial fibrillation due to vagal denervation. Aim of the work: to Assess the incidence and the value of postAF ablation cardiac autonomic dysfunction after Pulmonary vein isolation using radiofrequency and cryoballoon ablation techniques. Patients and Methods: This study enrolled 40 patients who underwent paroxysmal AF ablation at Ain Shams University hospitals. Patients were randomized into 2 groups, Radiofrequency ablation guided by 3D mapping (RF group; n=20) and Cryoballoon ablation using 2nd generation balloons (CB group; n=20). Valid 24-hour Holter for heart rate variability analysis was done for each patient pre ablation, after 1 month, after 3 months and after 12 months. Statistical comparison between both groups regarding HRV changes and clinical outcome was done. Results: The efficacy data in the form of freedom from AF at one year using radiofrequency technique was slightly higher than cryoballoon technique (75% Vs 65% respectively). However, this difference wasn’t statistically significant (P-value 0.490). During the 3-point follow up of HRV parameters (month-1, month-3 and month-12), changes in time domain and frequency domain parameters persisted for 12 months after both techniques, being more pronounced in RF group than CB group. The change in HRV parameters was in favour of vagal withdrawal and sympathetic dominance (there was a Significant decrease in SDNN, rMSSD and triangular index, on the other hand there was a significant increase in LF/HF).Conclusion: Cardiac autonomic dysfunction _assessed by Changes in time domain and frequency domain heart rate variability parameters_ persisted for 12 months after both techniques, being more pronounced in radiofrequency group than cryoballoon group.