AUTHOR=Pongratz Janis , Dorwarth Uwe , Riess Lukas , Schwartz Yitzhack , Wankerl Michael , Hoffmann Ellen , Straube Florian 

TITLE=Catheter Ablation in Complex Atrial Arrhythmias: Pilot Study Evaluating a 3D Wide-Band Dielectric Imaging System

JOURNAL=Frontiers in Cardiovascular Medicine

VOLUME=Volume 8 - 2021

YEAR=2022

URL=https://www.frontiersin.org/journals/cardiovascular-medicine/articles/10.3389/fcvm.2021.817299

DOI=10.3389/fcvm.2021.817299

ISSN=2297-055X

ABSTRACT=Background
Cryoballoon ablation (CBA) is a standard in atrial fibrillation (AF) ablation but might be not enough in complex atrial arrhythmias (AA). An open 3D wide-band dielectric imaging system (3D-WBDIS) has been introduced to guide CBA. 

Material and Methods
Pilot study evaluating 3D-WBDIS in combination with CBA and radiofrequency ablation (RFA) in patients with complex AA defined as 1) history of persistent AF, 2) additional atrial tachycardia/flutter, or 3) previous left atrial ablation.  

Results 
Prospectively, seventeen patients, mean age 68.9±12.2, with complex AA were enrolled. In 70 pulmonary veins (PV), 129 balloon positioning maneuvers were guided by the additional use of the occlusion tool (1.84/PV). Compared to angiography, the sensitivity and specificity of the occlusion tool was 94.5%, and 89%, respectively. CBA-PVI was achieved in 100% of PVs including PV variants. In 68 3D-WBDIS maps, the median number of mapping points was 251.0 (IQR 298.0), the map volume 52.8 (IQR 83.9) mL. Following CBA, six additional arrhythmias (two right and two left atrial flutter, one left atrial appendage tachycardia, and one AVNRT) were identified and successfully ablated by means of RFA in five patients (29.4%). No major complication occurred. After the blanking period and a median follow-up of 6 (IQR 1) months, the primary endpoint occurred in 7/17 patients (41%). Kaplan-Meier curves are presented in Figure 1. No additional complications during the clinical course following discharge were observed during follow-up.

Conclusion
The combined use of CBA with optional RFA guided by a novel 3D-WBDIS is feasible in patients suffering from complex AA. The occlusion tool shows high sensitivity and specificity for assessment of the balloon occlusion. Additional arrhythmias were successfully mapped and ablated. Short-term outcome is promising, larger outcome studies are necessary to confirm our findings.