| Part OnePreliminary study of remote control catheter ablation ofatrioventricular nodal reciprocating tachycardia usingMagnetic navigation systemAims: To evaluate the safety and feasibility of remote radiofrequency catheterablation of atrioventricular nodal reciprocating tachycardia (AVNRT) using themagnetic navigation system (MNS).Methods: A total of 37 patients (female 29, mean age 44±15 years) withdocumented AVNRT were enrolled in this study from March 2007 to June 2009. A 4mm tip magnetic mapping and ablation catheter ( Helios II, Stereotaxis, USA) , whichwas remotely controlled by the MNS (Niobe II, Stereotaxis, USA), was used for bothmapping and ablation. Conventional slow pathway modification with focal ablation atthe right posterior septum was first performed in all patients. If it was failed, linearlesions at the base of Koch's triangle was then done.Results: AVNRT was non-inducible in all 37 patients without any complicationexcept one case experienced transient first degree AV block. Focal ablation wasperformed in 34 patients, and linear ablation strategy was used in the remaining threecases to achieve the end point. Among all the 37 patients, slow pathway ablation wasachieved in 14, whereas slow pathway modification was reached in the remaining 23cases. The mean procedural time, the RF deliveries, the duration of RF applicationwere 119.4±32.3 min, 2.9±1.6 times, 127.5±32.3 s, respectively. The totalfluoroscopy time and the physician X-ray exposure time were 5.3±2.7 min and2.9±1.1 min, respectively. There was no significant change of the AH interval, theHV interval, and the atrioventricular nodal conduction refractory period after ablation. Compared with the first 18 patients, the mean procedural time, the total fluoroscopytime and the X-Ray fluoroscopy time during magnetic navigation were significantlydecreased in the second 19 patients (P<0.001). It demonstrates that the learning curveof remote catheter ablation using the MNS is short.ConclusionConclusion: Remote catheter ablation using the MNS to cure AVNRT is safeand effective with short learning curve and decreasing X-ray exposure time forinterventional physicians. ParPart 2Remote control catheter ablation of right ventricularoutflow tract premature ventricular contractions orventricular tachycardia using magnetic navigation systemcombined with noncontact mapping systemAims: To evaluate the safety and feasibility of remote radiofrequency catheterablation of right ventricular outflow tract ventricular premature contractions orventricular tachycardia (RVOT-PVCs/VT) using magnetic navigation system (MNS)combined with noncontact mapping system.Methods:Eighteen consecutive patients (female 12, mean age 45±12 years) withdocumented RVOT-PVCs/VT were referred for catheter ablation using the MNScombined with the noncontact mapping system. The Helios II/RMT magnetic catheterwas remotely controlled by the operator in the control room. If the arrhythmias werenot originated from RVOT or were failed by repeatedly ablation with MNS, manualablation with temperature controlled or irrigated catheter would be used.Results: A total of sixteen[ mean 1.6±0.8 (1-3) ] ventricular arrhythmias weresuccessfully abolished in ten of eighteen patients using remote ablation, and the acutesuccess rate was 55.5%. Five targets arised from the free wall, and the remaining 11ones from the septum of the RVOT. Among the eight patients who failed with MNS,non-RVOT origin was verified in three cases by detailed mapping and then switchedto manual ablation. One was in the distal of the great cardiac vein, one in the leftcoronary cusp, and another one seemed to be pulmonary artery truck origin. Manualablation was used in five patients with arrhythmias originated from RVOT failed withMNS. Among which the targets were inconstant during remote mapping and ablation in two patients, and irrigated catheter was used because of insufficient power of thetemperature controlled catheter in two patients. It indicated that the arrhythmia maybe originated from the epicardium in the patient failed with both remote and manualablation. The acute success rate of the enrolled patients was 88.9%. The mean time ofprocedure, the physician X-ray exposure, the total fluoroscopy and the X-Rayfluoroscopy during magnetic navigation were 171.0±40.3min, 3.7±2.7min,4.5±2.6min, 44.0±25.2s, respectively in the ten patients succeeded with MNS. Themean RF deliveries and the duration of RF application were 5.0±2.5 times and336.7±183.9 s. The mean time of procedure, the physician X-ray exposure, the totalfluoroscopy and the X-Ray fluoroscopy during magnetic navigation were195.6±29.6min, 6.5±1.3min, 7.8±1.2min, 78.1±45.8s, respectively. The mean RFdeliveries and the duration of RF application were 7.2±2.7 times and 441.1±256.5s inthe eight patients underwent manual ablation. No complications happened exceptcardiac tamponade occurred in one patient during irrigated ablation. Two casesrecurred after a mean follow-up of 9.2±4.7(3-17) months. One occurred in patientswith remote ablation, the other in patients switched to manual ablation.ConclusiConclusion: Remote catheter ablation using the MNS to cure RVOT-PVCs/VT issafe and effective with decreasing X-ray exposure time for the physicians and thepatients. |
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