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. 

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. 

Conclusion

The combined use of CBA with optional RFA guided by a novel 3D-WBDIS is feasible in patients suffering from complex AA. The specific occlusion tool shows high sensitivity and specificity for assessment of the balloon occlusion. Additional arrhythmias were successfully mapped and ablated. Further studies are necessary to evaluate if the strategy improves outcomes.


Figure: Atrial fibrillation and left atrial flutter ablation guided by dielectric imaging