PO-04-039 DIELECTRIC IMAGING-GUIDED ULTRA-LOW TEMPERATURE CRYOABLATION FOR ATRIAL FIBRILLATION

Abstract

Ultra-low temperature cryoablation(ULTC) can be used to create transmural ablation lesions in the left atrium (LA). With a circular catheter configuration, this energy modality can be used to create continuous ablation lesions around the pulmonary veins(PVs). The same catheter configuration can be used to isolate the posterior wall(PW) by creating multiple overlapping circular ablation lesions. Isolation of the PVs and the PW can be assessed using pacing maneuvers. Three-dimensional voltage mapping may provide additional information on the extent of the ablation lesions. A recently introduced dielectric imaging-based mapping system can be used to generate voltage maps and to visualize the ULTC ablation catheter. To evaluate the feasibility of ULTC, guided by dielectric imaging-based electroanatomic mapping. Patients with atrial fibrillation were consented for catheter ablation with the iCLAS cryoablation system(Adagio Medical, Laguna Hills, USA). Ablation included isolation of the PV’s and LA PW if deemed necessary. The KODEX-EPD system(EPD Solutions, Best, the Netherlands) was used in conjunction with a circular mapping catheter to create pre- and postablation voltage maps. If the postablation voltage map revealed incomplete ablation lesions, additional energy applications were applied. Patients visited the outpatient clinic at 3 months post ablation. All patients were enrolled in a prospective registry study that was approved by the local ethics committee. Six patients (4 male, 4 persistent AF, age 66±7 years, LAVI 38±14ml/m2) were treated. The PVs were targeted in all patients, while the PW was targeted in 5 patients. A postablation voltage map was generated in 5 patients, which revealed incomplete PV isolation in 2 patients and incomplete PW isolation in 1 patient. Additional ablation in these patients resulted in acute electrical isolation of all targets. Isolation of the PVs was achieved using a median of 11[IQR:9-15] energy applications and 11[8.5-14] minutes of ablation. Isolation of the PW required 6[6-7] applications and 3[3-3.5] minutes of ablation energy. Total mapping time was 14.5[12.5-22.5] minutes, total fluoroscopy time was 16[12.5-18.5] minutes, and the total procedure time was 107.5[67.25-123.5] minutes. At 3 months follow up, only 1 patient had recurrence of atrial arrhythmia. Longer follow up is ongoing. Dielectric imaging-based electroanatomic mapping can be used to evaluate lesions of ULTC.