Background: A novel irrigated RF balloon (RFB) for pulmonary vein isolation (PVI) was recently released. Early data suggest that definite impedance and temperature of the electrodes must be targeted to achieve PVI. We sought do further investigate if baseline and ablation related drop/rise of impedance and temperature electrodes may predict single shot sustained isolation (SSSI) during the first application at each PV.

Methods: Data from consecutive RFB procedures were collected and analysed. Application duration was set at 60 seconds anterior and 20 in the posterior electrodes. Operators were instructed to achieve a baseline impedance of at least 90 ohm in all electrodes. After the procedure detailed impedance and temperature data were extracted from the dedicated generator, only the first application at each PV was considered to avoid the confounder of multiple applications.

Results: In 27 consecutive patients 105 PVs were identified (3 LCPV). 104 PVs were targeted (one PV was not ablated because of a technical failure). Single shot PVI was recorded in 56/104 PVs (54%). The RIPV was the PV with the highest rate of SSI (73%) followed by LIPV (58%), RSPV (48%), LSPV (42%) and LCPV (0%). In 39/48 PVs without single shot isolation the PV was only transiently isolated. Mean time to SSSI was 11±8 seconds, and time to non sustained isolation was 13±8 seconds (p=0,23).

A minimal baseline electrode impedance of at least 90 ohm was reached in 51/104 Pvs (49%), however the mean minimal impedance was on target and no difference was found between SSSI and non-SSI (90±7ohm in each group, p=0,71). A similar analogy was found for baseline temperature (average maximal temperature 30±2°C in each group (p=0,87). During ablation, a similar impedance drop and temperature rise was recorded in both PVs with SSSI and non-SSSI (20±6 ohm vs 19±5 ohm and 11±3°C vs 10±3 °C, p=ns).

Conclusion: In this series the novel irrigated RFB led to a single shot sustained isolation in 54% of PVs. In inferior PVs single shot isolation was most frequently recorded compared to superior PVs. Once goal parameters are given to the operators, no baseline or variation in the impedance or temperature seem to predict single shot isolation.