Drastic reduction of RR variability and irregularity after surgical treatment of atrial fibrillation: A comparison between two ablation devices

Surgical treatments of atrial fibrillation (AF) create ablation lesions aiming at an electrical isolation that prevents AF initiation and maintenance. These lesions affect autonomic innervations of the atria, thus a reduction of RR variability is expected on a short and/or long period. The aim of this study is to assess the changes on variability and irregularity of RR series after ablation performed by an innovative high intensity focused ultrasound (HIFU) device, and by a classic bipolar radiofrequency (RF) device. Time and frequency domain HRV parameters, as well as Poincar plot derived indexes and entropy measure were computed before and after 12 months the operation in two groups of patients: the Study Group (SG) treated with HIFU system and the Control Group (CG) treated with RF device. Results show that after ablation, a reduction of variability and irregularity can be observed in both groups. From these preliminary results, we observed that both devices depressed post-ablation HRV on short term and long term (one year). HIFU lesions had a larger effect than bipolar RF device.