Robotic assistance and general anaesthesia improve catheter stability and increase signal attenuation during atrial fibrillation ablation.
OBJECTIVE
Recurrent arrhythmias after ablation procedures are often caused by recovery of ablated tissue. Robotic catheter manipulation systems increase catheter tip stability which improves energy delivery and could produce more transmural lesions. We tested this assertion using bipolar voltage attenuation as a marker of lesion quality comparing robotic and manual circumferential pulmonary vein ablation for atrial fibrillation (AF).


RESULTS
Twenty patients were randomly assigned to robotic or manual AF ablation at standard radiofrequency (RF) settings for our institution (30 W 60 s manual, 25 W 30 s robotic, R30). A separate group of 10 consecutive patients underwent robotic ablation at increased RF duration, 25 W for 60 s (R60). Lesions were marked on an electroanatomic map before and after ablation to measure distance moved and change in bipolar electrogram amplitude during RF. A total of 1108 lesions were studied (761 robotic, 347 manual). A correlation was identified between voltage attenuation and catheter movement during RF (Spearman's rho -0.929, P < 0.001). The ablation catheter was more stable during robotic RF; 2.9 ± 2.3 mm (R30) and 2.6 ± 2.2 mm (R60), both significantly less than the manual group (4.3 ± 3.0 mm, P < 0.001). Despite improved stability, there was no difference in signal attenuation between the manual and R30 group. However, there was increased signal attenuation in the R60 group (52.4 ± 19.4%) compared with manual (47.7 ± 25.4%, P = 0.01). When procedures under general anaesthesia (GA) and conscious sedation were analysed separately, the improvement in signal attenuation in the R60 group was only significant in the procedures under GA.


CONCLUSIONS
Robotically assisted ablation has the capability to deliver greater bipolar voltage attenuation compared with manual ablation with appropriate selection of RF parameters. General anaesthesia confers additional benefits of catheter stability and greater signal attenuation. These findings may have a significant impact on outcomes from AF ablation procedures.
Imperial College Healthcare NHS Trust, St Mary's Hospital, Praed Street, London W2 1NY,  UK.
Louisa C
LC
Malcolme-Lawes
Phang Boon
PB
Lim
Michael
M
Koa-Wing
Zachary I
ZI
Whinnett
Shahnaz
S
Jamil-Copley
Sajad
S
Hayat
Darrel P
DP
Francis
Pipin
P
Kojodjojo
D Wyn
DW
Davies
Nicholas S
NS
Peters
Prapa
P
Kanagaratnam
D000768:Anesthesia, General / Q000379:methods; D018681:Anesthetics, General / Q000627:therapeutic use*; D001281:Atrial Fibrillation / Q000175:diagnosis* / Q000601:surgery*; D017115:Catheter Ablation / Q000379:methods*; D005260:Female; D006329:Heart Conduction System / Q000601:surgery; D006801:Humans; D008297:Male; D008875:Middle Aged; D011667:Pulmonary Veins / Q000601:surgery*; D012371:Robotics / Q000379:methods*; D025321:Surgery, Computer-Assisted / Q000379:methods*; D016896:Treatment Outcome
D018681:Anesthetics, General