Robotic magnetic navigation for ablation of human arrhythmias: initial experience.
BACKGROUND
Magnetic navigation system (MNS) (Niobe, Stereotaxis, Saint-Louis, Missouri, USA) allows remote control of a radiofrequency ablation catheter using a steerable magnetic field and a catheter advancement system.


OBJECTIVE
We report our initial experience of ablation of human arrhythmias using the MNS.


METHODS
Eighty-four patients (mean age 54+/-17years; 39 women) had an electrophysiologic study followed by ablation with the MNS using non-irrigated 4, 8 and 3.5mm-tip catheters with three distal magnets. All patients were symptomatic, with commonly-accepted indications for ablation: atrioventricular nodal re-entrant tachycardia (AVNRT; n=37); typical atrial flutter (n=15); accessory pathway (n=12); atypical atrial flutter (n=7); ventricular tachycardia (n=7); atrial tachycardia (n=3); paroxysmal atrial fibrillation (n=3). Electroanatomical mapping was used for atrial flutter, atrial fibrillation, atrial tachycardia and ventricular tachycardia procedures (29 patients, 34%).


RESULTS
Ablation was performed successfully in 69 (82%) patients. In 15 patients (18%), MNS technique was unsuccessful: seven typical atrial flutters, four accessory pathways, two left atrial flutters after atrial fibrillation ablation, one ventricular tachycardia and one AVNRT; in all these cases except one typical atrial flutter and two left atrial flutters, success was obtained by switching to the manual technique by means of an irrigated catheter. Total fluoroscopy time was 14+/-11minutes; operator exposure fluoroscopy time was 1.5+/-0.6minutes; procedure time was 169+/-72minutes.


CONCLUSIONS
MNS ablation is a feasible treatment for various human arrhythmias, with a high success rate. Mapping with a magnetic catheter is safe. However, magnetic ablation of typical atrial flutter remains challenging, probably because of insufficient pressure for cavotricuspid isthmus ablation.
Latcu
Decebal G
DG
Cardiologie, centre hospitalier Princesse-Grace, avenue Pasteur, 98000 Monaco, Monaco.
Ricard
Philippe
P
Zarqane
Naima
N
Yaici
Khelil
K
Rinaldi
Jean-Paul
JP
Maluski
Alexandre
A
Saoudi
Nadir
N
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001145:Arrhythmias, Cardiac / Q000601:surgery*; D017115:Catheter Ablation / Q000009:adverse effects / Q000295:instrumentation / Q000379:methods*; D002648:Child; D004867:Equipment Design; D005240:Feasibility Studies; D005260:Female; D005471:Fluoroscopy; D006801:Humans; D008280:Magnetics / Q000295:instrumentation; D008297:Male; D008875:Middle Aged; D010865:Pilot Projects; D011446:Prospective Studies; D012008:Recurrence; D012371:Robotics / Q000295:instrumentation; D025321:Surgery, Computer-Assisted / Q000295:instrumentation; D013997:Time Factors; D016896:Treatment Outcome; D055815:Young Adult