Background:

Very high power short duration (vHPSD) ablation (70watts/5-7 seconds) is highly efficient and safe and reducing procedure and RF time in pulmonary vein isolation (PVI). Due to the short ablation time catheter stability is crucial. Little is known regarding catheter stability using the Flexability catheter due to the lack of contact force features. We aimed to compare catheter stability as well as biophysical characteristics in very HPSD ablation compared to standard ablation for PVI.

Methods:

We compared n=48 patients undergoing PVI for paroxysmal AF (vHPSD (n=34) or SD ablation (n=14)). We analysed all RF lesions with n=3653 lesions in the vHPSD group and n=1190 lesions in the standard group for applied current, applied energy, and impedance drop during ablation. Furthermore, location of the catheter tip was compared at the beginning and the end of ablation.

Results:

Catheter movement during ablation was significantly greater in the SD group with 7.9mm +/-8.3mm compared to 4.5mm +/- 4.4mm in the HPSD group (Figure 1 and Table 1).

Overall applied energy was significantly higher in the standard ablation group (704.6.3 +/- 431.1J) compared to the HPSD group (489.8 +/- 54.2J) (p=<0.001). Minimal, maximal and mean applied current per lesion where significantly higher in the HPSD group. The mean measure impedance drop for each lesion was 13.9 +/- 6.6 Ohm in the HPSD group and 16.8 +/- 7.4 Ohm in the standard power group (p=0.001) with an impedance drop of 12.7 +/- 4.3% in the HPSD group compared to 16.6 +/- 8.2 in the standard ablation group (p=0.001) (Table 2). 

Conclusion:

Catheter stability was significantly impaired in the standard group with significantly greater catheter dislocation compared to HPSD ablation. Overall delivered energy was higher in the standard group whereas mean, minimal and maximal delivered current was significantly higher in the HPSD group.