Remote Magnetic Navigation System Research Articles

The feasibility of using remote magnetic navigation system as the primary technological training tool for novice cardiac electrophysiology operators in the catheter ablation of left-sided accessory pathway.

For novice operators, mastering catheter ablation of left-sided accessory pathway (LSAP) in a short duration of time without compromising efficacy and safety remains a challenge. In this study an attempt to shorten the learning curve by using robotics via a remote magnetic navigation (RMN) system was performed. Novice physician fellows without prior catheter ablation experience initiated their process of learning LSAP ablation using the Niobe™ RMN system. Their procedure parameters were recorded and compared with experienced operators using RMN and manual catheter navigation (MCN). Novice operators quickly shortened the total procedure time after their first five procedures. In subsequent procedures, no significant difference in procedure time, fluoroscopy exposure or ablation time was observed between novice and experienced RMN operators. When compared to MCN operators, novice operators avoided excessive radiation exposure beginning with their first RMN procedure, while lower fluoroscopy doses were noted after five procedures. It was observed that procedure parameters did not differ significantly according to LSAP location. The RMN system is a practical and easy to use tool for novice electrophysiology operators to quickly master LSAP ablation, without compromising efficacy or safety. Additionally, when compared to MCN it also protects the operators and patients from excessive radiation exposure during the procedure.

Telerobotic interventions from a distance: an initial experience in 3D phantom mapping

IntroductionThe current COVID-19 pandemic has fostered several accelerations in “remote” patient care such as video and telephone clinics, as well as multidisciplinary collaborations using online platforms with experts consulting the local teams from a distance. The next logical step would be to also offer remote-controlled interventions which the expert operator not on site, but in support of the local team. This is especially valuable for complex interventions when either patient or expert operator can not be present at the same place.PurposeWe aimed to demonstrate that an expert operator located at far distance (Austria) could directly interact with the remote magnetic navigation system in London (UK) whilst mapping a 3D phantom using an electroanatomical mapping system.MethodTwo experienced operators of the magnetic navigation system were tasked with creating fast anatomic maps (FAM) of the atrial and ventricular chambers of a 3D phantom using remote magnetic navigation in combination with 3D electroanatomical mapping. One was located in the control room of the magnetic catheter lab (UK) and the second one was in Tirol, Austria and connected through a secure remote desktop connection (via high speed fibre optic cable). Using a solid tip magnetic catheter connected to a mechanical drive, all interactions with the system were carried out via the Odyssey platform. Acquisitions for right and left atrium, as well as right and left ventricles plus aorta was compared with regards to mapping duration, map completeness (as judged by the average distance of surface points from 3D CT scan reconstruction), total 3D map volume and need for additional radiation exposure during the mapping process.ResultsMapping time and map completeness when performed by the distant operator was not inferior to the local operator and both did not require any additional radiation exposure during the mapping process. Table 1 demonstrates the mean parameters for each chamber, respectively. Figure 1 depicts the matched data for chamber completeness as compared for the LA (green= local operator, pink= distant operator) using a contrast CT scan as the gold standard.ConclusionTelerobotic 3D mapping of a 3D phantom from a distance was equally fast delivered from the control room as compared to an operator located 1200 km away without compromising on map completeness. This demonstrates the feasibility of telerobotic interventions and stress the need for remote collaboration which is especially valuable when travel of patients and/or physician experts is restricted.Funding AcknowledgementType of funding sources: None. Matched data for aorta

Telerobotic interventions from a distance: an initial experience in 3D phantom mapping

Abstract Introduction The current COVID-19 pandemic has fostered several accelerations in “remote” patient care such as video and telephone clinics, as well as multidisciplinary collaborations using online platforms with experts consulting the local teams from a distance. The next logical step would be to also offer remote-controlled interventions which the expert operator not on site, but in support of the local team. This is especially valuable for complex interventions when either patient or expert operator can not be present at the same place. Purpose We aimed to demonstrate that an expert operator located at far distance (Austria) could directly interact with the remote magnetic navigation system in London (UK) whilst mapping a 3D phantom using an electroanatomical mapping system. Method Two experienced operators of the magnetic navigation system were tasked with creating fast anatomic maps (FAM) of the atrial and ventricular chambers of a 3D phantom using remote magnetic navigation in combination with 3D electroanatomical mapping. One was located in the control room of the magnetic catheter lab (UK) and the second one was in Tirol, Austria and connected through a secure remote desktop connection (via high speed fibre optic cable). Using a solid tip magnetic catheter connected to a mechanical drive, all interactions with the system were carried out via the Odyssey platform. Acquisitions for right and left atrium, as well as right and left ventricles plus aorta was compared with regards to mapping duration, map completeness (as judged by the average distance of surface points from 3D CT scan reconstruction), total 3D map volume and need for additional radiation exposure during the mapping process. Results Mapping time and map completeness when performed by the distant operator was not inferior to the local operator and both did not require any additional radiation exposure during the mapping process. Table 1 demonstrates the mean parameters for each chamber, respectively. Figure 1 depicts the matched data for chamber completeness as compared for the LA (green= local operator, pink= distant operator) using a contrast CT scan as the gold standard. Conclusion Telerobotic 3D mapping of a 3D phantom from a distance was equally fast delivered from the control room as compared to an operator located 1200 km away without compromising on map completeness. This demonstrates the feasibility of telerobotic interventions and stress the need for remote collaboration which is especially valuable when travel of patients and/or physician experts is restricted. Funding Acknowledgement Type of funding sources: None. Matched data for aorta

Novel strategy of remote magnetic navigation-guided ablation for ventricular arrhythmias from right ventricle outflow tract

The optimized strategy to further increase the success rate of ablation for ventricular arrhythmias (VAs) from the right ventricular outflow tract (RVOT) is challenging. Recent studies have shown that the pulmonary sinus cusp (PSC) region may be the origin of certain RVOT VAs. We evaluated the efficacy of preferential ablation below the pulmonary valve (PV) and alternated radiofrequency delivery in the PSC using remote magnetic navigation (RMN). Sixty-five (65) consecutive patients experiencing VAs with RVOT-like appearance were included in this study. Mapping and ablation were preferentially performed below the PV. Ablation in the PSC would only be attempted when intensified ablation below the PV could not eliminate VAs. Finally, if ablation in the RVOT region failed, the aortic sinus cusp (ASC) would be mapped. Sixty-one (61) of 65 (93.8%) patients achieved procedural success. Except 7 cases of which the VAs were ablated in the ASC, the rest 54 VAs were thought to be originate from the RVOT region. Fifty (50) of 54 VAs were successfully ablated below the PV, and in the presence of a local special signal in the bipolar electrogram a more aggressive ablation was required. Subsequent ablation in the PSC with assistance of the RMN system achieved success in the remaining 4 patients. No complications occurred in this study. Our strategy of using RMN-guided ablation below the PV for VAs of RVOT origin was proved to be effective. PSC mapping and ablation using a magnetic catheter may provide the optimal strategy for treating these types of arrhythmias.

4282Pulmonary artery denervation in patients with residual pulmonary hypertension after pulmonary endarterectomy: one-year results of the first -in-man, sham-controlled, pilot randomized clinical trial

Abstract Background Pulmonary endarterectomy (PE) is the method of choice in patients with chronic thromboembolic pulmonary hypertension (CTEPH). Despite the positive effect after surgery combined with medical treatment, 10–40% of patients develop residual CTEPH. Pulmonary artery denervation (PAD) is a novel treatment in PAH with optimistic results but was not tested in patients with residual CTEPH. Objective To assess the safety and efficacy of PAD using remote magnetic navigation system in patients with residual CTEPH after PE. Methods 278 patients with CTEPH after PE were screened. 50 patients (mean age 47.6±14.3, 50% female) with a history of residual CTEPH (a resting pulmonary artery pressure ≥25 mm Hg or pulmonary vascular resistance >400 dyn sec cm–5 despite medical therapy 6 months after PE) were randomized into two groups: PAD (n=25; PAD group) or medical therapy with riociguat (n=25; MED group). In both groups right heart catheterization (RHC)was performed after randomization. In the PAD group, remote magnetic navigation systemwas used to target sympathetic nerve fibers, located near bifurcation and ostia of the main brunches of right and left pulmonary arteries. This study was conducted as double-blind and sham-controlled and the primary endpoint was change in pulmonary vascular resistance (PVR) by RHC at 12 months. Secondary endpoints included 6-minute walk test (6MWT), pulmonary artery pressure, and clinical outcomes. All patients were followed for 12 months after randomization. Unpaired t-test and Fisher's exact test were used for between-group comparisons of continuous and categorical variables, respectively. A p value of less than 0.05 was considered statistically significant. Results Two patients (one in each group) developed groin hematoma which resolved without any consequences. At the end of 12 month, the PVR was significantly low in PAD group as compared with MED group (343±149 dyn sec cm–5 vs 444±145 dyn sec cm–5, respectively; mean difference −101, 95% confidence interval: −193 to −10; p=0.032). The mean, systolic and diastolic PA pressure was also reduced significantly in PAD group compared to MED group (25.8±7.3mm Hg vs 33.8±6.4 mm Hg, 46.2±14.1mm Hg vs 54.2±8.1 mm Hg,13.2±5.3mm Hg vs 20.2±4.8mm Hg; p<0.001, p=0.002, p<0.001, respectively). The PAD group demonstrated significant improvement of the 6MWT over MED group (470±84 m vs 399±116 m, respectively, p=0.031). In the PADN group 1 (4%) patient was hospitalized due to heart failure progression compared to 7 (29%) patients in MED group (p=0.049). One patient in PAD group and two patients in MED group died. Conclusions Pulmonary artery denervation in patients with residual pulmonary hypertension was safe and effective, and resulted in substantial reduction of pulmonaryvascular resistance and pulmonary artery pressure during 12 months follow up, accompanied by improved 6-minute walk test and reduced need for hospitalization. Clinical Trials Registration: NCT02745106 Acknowledgement/Funding Grant from Biosense Webster

P5691Independent assessment if an image-processing service for the treatment of patients with ventricular tachycardias

Abstract Background/Introduction Substrate-based radiofrequency ablation (RFA) in combination with pre-procedural computed tomography (CT) or cardiac Magnetic Resonance Imaging (cMRI) emerged as a promising approach to treat ventricular tachycardias (VT). However, image-processing and 3D reconstruction of the relevant structures to embed them into a 3D electroanatomical mapping (EAM) system is time consuming and requires highly experienced personal and a dedicated software. Purpose The aim of the study was to present the first independent experience with a commercially available service of a internet platform in patients referred for RFA of VTs. Methods Seven consecutive patients (pts) with ischemic cardiomyopathy (ICM), non- ischemic cardiomyopathy (NICM) and dilated cardiomyopathy (DCM) referred for VT RFA underwent contrast-enhanced dual-energy CT. The anonymized DICOM dataset was uploaded to the internet platform. After processing by the specialists, the dataset was downloaded and exported in a format compatible with the 3D EAM System. The EAM was performed in sinus rhythm using a 3.5mm open-irrigated tip catheter or a magnetic remote 3.5mm open-irrigated tip catheter in combination with the remote magnetic navigation-system. A multipolar high-density mapping catheter was used in 6 pts. Scar was defined as bipolar voltage <0.5 mV, and scar border zone ≥0.5mV and <1.5 mV. Results of the internet platform-derived wall thinning (WT), scars and the defined substrate based on 3d EAM voltage maps were transferred into a 17-segment model, and the filling of every single segment was rated as 0%, 25%, 50%, 75% and 100%. For analysis, agreement of the filling (percentage) of the individual segments was quantified. Results Mean age was 67±8 year, BMI was 28±5 kg/m2 and 86% were males. File transfers and image processing was feasible in all patients. Agreement between the defined substrate (<0,5mV) and WT of 4mm was very good (≥90%) in 3 pts, good (≥75% & <90%) in one patient, moderate (≥50% & <75%) in one patient and poor (<50%) in one patient. Patient #1 #2 #3 #4 #5 #6 #7 Sex male male male female male male male Age 63y 56y 71y 65y 60y 69y 81y BMI 31kg/m2 32kg/m2 19kg/m2 25kg/m2 28kg/m2 34kg/m2 29kg/m2 LVEF 25% 60% 25% 25% 25% 31% 34% EDVI 123ml/m2 184ml/m2 69ml/m2 114ml/m2 142ml/m2 105ml/m2 75ml/m2 Catheter multipolar high-density + 3.5mm open-irrigated tip 3.5mm open-irrigated tip multipolar high-density + 3.5mm open-irrigated tip multipolar high-density + 3.5mm open-irrigated tip multipolar high-density + magnetic remote 3.5mm open-irrigated tip multipolar high-density + magnetic remote 3.5mm open-irrigated tip multipolar high-density + magnetic remote 3.5mm open-irrigated tip Quality 98% 96% 91% 66% 89% no match 53% Quality = Percentage match between defined substrate and WT. Superimpose – wall thinning and FAM Conclusion(s) Integration of substrate-based segmentation using the service of the internet platform is feasible in daily practice. Agreement between voltage-map based substrate definition and internet platform-based WT was satisfactory in the majority of patients.

An efficient cardiac mapping strategy for radiofrequency catheter ablation with active learning

ObjectiveA major challenge in radiofrequency catheter ablation procedures is the voltage and activation mapping of the endocardium, given a limited mapping time. By learning from expert interventional electrophysiologists (operators), while also making use of an active-learning framework, guidance on performing cardiac voltage mapping can be provided to novice operators or even directly to catheter robots.MethodsA learning from demonstration (LfD) framework, based upon previous cardiac mapping procedures performed by an expert operator, in conjunction with Gaussian process (GP) model-based active learning, was developed to efficiently perform voltage mapping over right ventricles (RV). The GP model was used to output the next best mapping point, while getting updated towards the underlying voltage data pattern as more mapping points are taken. A regularized particle filter was used to keep track of the kernel hyperparameter used by GP. The travel cost of the catheter tip was incorporated to produce time-efficient mapping sequences.ResultsThe proposed strategy was validated on a simulated 2D grid mapping task, with leave-one-out experiments on 25 retrospective datasets, in an RV phantom using the Stereotaxis Niobe® remote magnetic navigation system, and on a tele-operated catheter robot. In comparison with an existing geometry-based method, regression error was reduced and was minimized at a faster rate over retrospective procedure data.ConclusionA new method of catheter mapping guidance has been proposed based on LfD and active learning. The proposed method provides real-time guidance for the procedure, as well as a live evaluation of mapping sufficiency.

Catheter Ablation of Complex Tachyarrhythmias Using Remote Magnetic Catheter Navigation System

Catheter Ablation of Complex Tachyarrhythmias Using Remote Magnetic Catheter Navigation System

Abstract 16480: Characteristics and Outcomes of Patients With Papillary Muscle Ventricular Arrhythmias

Introduction: We sought to investigate the characteristics and outcomes of patients who underwent RF ablation of PM ventricular arrhythmias (VA) in our center. Results: 26 patients were included, median age was 66 years (16 to 85), 46% female, all with normal LVEF. PM VAs were PVCs in 68% patients, and PVC + VT in 32%. Site of origin was the LV infero-septal PM in 73%, LV antero-lateral PM in 15% and right ventricular RV septal PM in 12%. 46% of patients showed other VAs in addition to the one originating from the PMs; in 33% of these patients, additional VAs were 2 or more. These VAs were mostly PVCs (92%), localized in the LVOT (64% - 56 % in the basal LV and 44% in the aortic cusps) and the septal RVOT (36%). The only additional VT was fascicular. All the PMs and mappable additional VAs were ablated with RF energy through an irrigated catheter and the aid of ICE; a remote magnetic navigation system (RMS) was used in half of the procedures. In one case, PVC suppression required additional epicardial ablation. Major complications occurred in 2 patients (8%): 1 pericardial effusion (the patient underwent ablation of a crista terminalis premature atrial complex in the same procedure) and 1 pseudoaneurysm. Acute success (PM VA suppression/non-inducibility) was achieved in 96% of patients (the patient with pericardial effusion could be anticoagulated further and the procedure was stopped). After a median follow-up period of 8 (4-14) months, long-term success (no PM VT recurrence or PVC burden reduced by 80% off antiarrhythmic drugs) was 92% after a single procedure, 96% after repeat procedures. When considering additional VAs, the only recurrence was a parahisian RVOT PVC. No difference in acute or overall long-term success was observed when comparing RMS-guided vs standard procedures (respectively 92% vs 100 % and 100% vs 92%; P = NS). Conclusion: PM VAs are most commonly PVCs originating from the LV infero-septal PM and are frequently (48%) associated with an additional ventricular focus (LVOT > RVOT >> fascicular VT). RF ablation is safe and effective in eliminating or significantly reduce the burden of PM VAs, as well the extra-PM foci that are commonly encountered in this population. RMS guided ablation is not inferior to standard ablation in this subset of patients.

Long-term outcomes of remote magnetic navigation for ablation of supraventricular tachycardias.

Little is known about the long-term outcomes of catheter ablation of supraventricular tachycardia (SVT) using remote magnetic navigation system (RMN). One hundred twenty patients underwent catheter ablation of SVTs with RMN (Niobe, Stereotaxis, USA): atrioventricular nodal re-entrant tachycardia (AVNRT; n = 59), atrioventricular re-entrant tachycardia (AVRT; n = 45), and focal atrial tachycardia (AT, n = 16). The outcome of AVRT with right free wall accessory pathway was compared with those of a group of 26 consecutive patients undergoing manual ablation. Mean follow-up period was 2.2 ± 1.4 years. Overall arrhythmia-free survival was 86%; AVRT (77%), AVNRT (96%), and focal AT (71%). After the learning period (initial 50 cases), procedural outcomes had improved for AVRT and AVNRT (91% in overall group, 90% in AVRT group, 100% in AVNRT group, and 68% in focal AT group). The recurrence-free rate was higher for the free wall accessory pathways than those of the other sites (92 vs. 73%, log-rank P = 0.06). Furthermore, when it is confined for the right free wall accessory pathway, RMN showed excellent long-term outcome (7/7, 100 %) compared to the results of manual approach (18/26, 69.2%, log-rank P = 0.07). RMN showed favorable long-term outcomes for the ablation of SVT. In our experience, RMN-guided ablation may be associated with a higher success rate as compared to manual ablation when treating right-sided free wall pathways.

Remote magnetic navigation for ablation of typical atrial flutter: Long-term results

Introduction and AimRemote magnetic navigation has proved to be effective in the ablation of most supraventricular and ventricular arrhythmias. Initial studies reported worse results with this system compared to conventional ablation for atrial flutter. The aim of this study was to assess the acute and long-term success of atrial flutter ablation with remote magnetic navigation and to retrospectively compare the results obtained with an 8-mm tip catheter versus an irrigated catheter. MethodsWe studied 38 consecutive patients, mean age 61±15 years, 28 male, who underwent ablation of typical atrial flutter with the Niobe II remote magnetic navigation system (Stereotaxis). Ablation was performed with an 8-mm tip catheter in 17 patients and with an irrigated-tip catheter in 21 patients. Acute success was defined as the presence of bidirectional isthmus block, and long-term success as absence of symptoms and atrial flutter during Holter monitoring. ResultsBidirectional isthmus block was achieved in 37 patients (97%), and the success rate was similar in both groups. Total procedure time was not significantly different between the groups but fluoroscopy time was shorter in the irrigated tip group (13.4±3.7 min vs. 6±4.4 min; p<0.01). The number of applications and total radiofrequency time did not differ. There were no complications. During a follow-up of 32±19 months there were two relapses, one in each group. ConclusionsThe Niobe II remote control system for ablation of typical atrial flutter is safe and effective in both the short and long term. The 8-mm and irrigated-tip catheters showed similar safety and efficacy.

Ablação do istmo cavo‐tricúspide com sistema de navegação magnética por controlo remoto no tratamento do flutter auricular típico – resultados a longo prazo

Introduction and AimRemote magnetic navigation has proved to be effective in the ablation of most supraventricular and ventricular arrhythmias. Initial studies reported worse results with this system compared to conventional ablation for atrial flutter. The aim of this study was to assess the acute and long‐term success of atrial flutter ablation with remote magnetic navigation and to retrospectively compare the results obtained with an 8‐mm tip catheter versus an irrigated catheter. MethodsWe studied 38 consecutive patients, mean age 61±15 years, 28 male, who underwent ablation of typical atrial flutter with the Niobe II remote magnetic navigation system (Stereotaxis). Ablation was performed with an 8‐mm tip catheter in 17 patients and with an irrigated‐tip catheter in 21 patients. Acute success was defined as the presence of bidirectional isthmus block, and long‐term success as absence of symptoms and atrial flutter during Holter monitoring. ResultsBidirectional isthmus block was achieved in 37 patients (97%), and the success rate was similar in both groups. Total procedure time was not significantly different between the groups but fluoroscopy time was shorter in the irrigated tip group (13.4±3.7 min vs. 6±4.4 min; p<0.01). The number of applications and total radiofrequency time did not differ. There were no complications. During a follow‐up of 32±19 months there were two relapses, one in each group. ConclusionsThe Niobe II remote control system for ablation of typical atrial flutter is safe and effective in both the short and long term. The 8‐mm and irrigated‐tip catheters showed similar safety and efficacy.

Does a patent foramen ovale matter when using a remote-controlled magnetic system for pulmonary vein isolation?

Pulmonary vein isolation (PVI) takes longer when using a patent foramen ovale (PFO) compared with a transseptal puncture in paroxysmal atrial fibrillation (AF) with manual catheter ablation. To our knowledge, no data exist concerning the impact of a PFO on AF ablation procedure variables when using a remote magnetic navigation (RMN) system. To assess the impact of a PFO when using an RMN system in patients requiring AF ablation. Between December 2011 and December 2012, catheter ablation was performed remotely using the CARTO(®) 3 system in 167 consecutive patients who underwent PVI for symptomatic drug-refractory AF. The radiofrequency generator was set to a fixed power ≤ 35 W. The primary endpoint was wide-area circumferential PVI confirmed by spiral catheter recording during ablation for all patients and including additional lesion lines (left atrial roof) or complex fractionated atrial electrograms for persistent AF. Secondary endpoints included procedural data. Mean age 58±10 years; 18% women; 107 (64%) patients with symptomatic paroxysmal AF; 60 (36%) with persistent AF; CHA2DS2-VASc score 1.2 ± 1. The PFO presence was evidenced in 49/167 (29.3%) patients during the procedure but in only 26/167 (16%) by transoesophageal echocardiography. Median procedure time 2.5 ± 1 hours; median total X-ray exposure time 14 ± 7 minutes; transseptal puncture and catheter positioning time 7.5 ± 5 minutes; left atrium electroanatomical reconstruction time 3 ± 2.3 minutes; catheter ablation time 3 ± 3 minutes. No procedure time or X-ray exposure differences were observed between patients with or without a PFO during magnetic navigation catheter ablation. X-ray exposure time was significantly reduced using a PFO compared with double transseptal puncture access. A PFO does not affect magnetic navigation during AF ablation; procedure times and X-ray exposure were similar. Septal catheter probing is mandatory to limit X-ray exposure and prevent potential complications.

Non-Fluoroscopic Transseptal Catheterization During Electrophysiology Procedures using a Remote Magnetic Navigation System.

Transseptal punctures are commonly performed, and left atrial (LA) access is frequently lost during lengthy, complex electrophysiology (EP) procedures. We describe a new technique for non-fluoroscopic re-crossing the fossa ovalis using a new multielectrode transseptal sheath (TS) and a new remote magnetic catheter navigation system (RMNS) (CGCI System, Magnetecs) that uses 8 rapid external electromagnets for real-time navigation of a magnet-tipped electrode catheter across the initial transseptal puncture site in 5 patients undergoing left-sided ablation procedures. The three-dimensional (3D) position of a 8.5 Fr steerable TS with 5-ring 5-15-15-5-mm spaced distal electrodes (Agilis ES©, St Jude Medical), and site of fossal ovalis crossing were "shadowed landmarks" on a 3D electroanatomic mapping (EAM) system (EnSite/NavXTM, St Jude Medical). The TS-magnetic ablation catheter assembly was pulled-back to the inferior vena cava. EAM landmarks were used with RMNS-guided "manual" and "automated" catheter navigation modalities, until septal crossing was obtained. Transseptal re-crossing was successfully performed in all patients in 6.2±8.1 sec using the "automated" RMNS-guided technique and in 30.4±28.4 sec using the "manual" RMNS-guided technique (p=0.01) without complications. This new RMNS was safely and effectively used to perform non-fluoroscopic transseptal catheterization.

Contemporary Outcomes of Supraventricular Tachycardia Ablation in Congenital Heart Disease

Background— Remote magnetic navigation–guided ablation with 3-dimensional (3D)-image integration could provide maximum benefit in patients with complex anatomy. We reviewed supraventricular tachycardia (SVT) ablation in adult patients with congenital heart disease to assess the contribution of these technologies. Methods and Results— One hundred fifty-four SVT ablation procedures (228 SVTs) using a 3D-electroanatomic mapping system in 116 adult patients with congenital heart disease (mean age, 41; 76 male) were classified into 3 groups: Group A, manual mapping/ablation (n=60 procedures); Group B, remote magnetic navigation–guided mapping/ablation with normal femoral vein access (49); and Group C, remote magnetic navigation–guided mapping/ablation with difficult access (45). Group A included simple anomalies with less SVTs. Group B comprised predominantly Fontan patients with more SVTs. Group C included more complex defects, such as intra-atrial baffle or interrupted inferior venous access, in which retrograde aortic and superior venous accesses were used exclusively with more frequent use of image integration (97.8%; P &lt;0.001). Acute success was 91.5%, 83.7%, and 82.2%, respectively ( P =0.370). In group C, fluoroscopy time was the shortest (median, 4.2 min; P &lt;0.001) despite the longer procedure duration (median, 253 min; P &lt;0.001). SVTs free rates were 80.4%, 82.4%, and 75.8%, respectively ( P =0.787) during a mean 20-months follow-up period. Conclusions— The combination of remote magnetic navigation, 3D-image integration, and electroanatomic mapping system facilitated safe and feasible ablation with very low fluoroscopy exposure even in patients with complex anomalies.

Feasibility of remote magnetic navigation for epicardial ablation

Percutaneous epicardial mapping and ablation is an emerging method to treat ventricular tachycardias (VT), premature ventricular complexes (PVC), and accessory pathways. The use of a remote magnetic navigation system (MNS) could enhance precision and maintain safety. This multiple case history demonstrates the feasibility and safety of the MNS-guided epicardial approach in mapping and ablation of ischaemic VT, outflow tract PVCs, and a left-sided accessory pathway. All patients had previously undergone endocardial mapping for the same arrhythmia. MNS could present an advantage from more precise navigation for mapping and maintaining catheter stability during energy application.

Catheter ablation in children and young adults: is there an additional benefit from remote magnetic navigation?

PurposeAlthough rare, children and young adults can suffer from significant cardiac arrhythmia, especially in the context of congenital malformations and after cardiac surgery.MethodsA total of 62 patients (32 female, median age 20 years) underwent an invasive electrophysiology study between 2008–2011: half had normal cardiac anatomy, whereas the remaining patients had various types of congenital heart disease. All patients were treated using either conventional techniques (CVN) or remote magnetic navigation (RMN).ResultsPatients treated with the RMN system differed substantially from patients in the CVN group with respect to presence of congenital heart disease (67 % vs. 37 %), previous cardiac surgery (59 % vs. 20 %) or failed previous conventional ablation (22 % vs. 9 %), respectively. Although these more complex arrhythmias resulted in longer median procedure duration (180 vs. 130 min, p = 0.034), the median overall fluoroscopy exposure in the RMN group was significantly lower (4.1 vs. 5.2 min, p = 0.020). Clinical outcome was comparable in both groups without complications caused by the ablation.ConclusionsCatheter ablation using remote magnetic navigation is safe and feasible in children and young adults and is especially valuable in patients with abnormal cardiac morphologies. RMN resulted in significantly lower radiation exposure compared with the conventional technique.

Reaching the ventricular aspect of the inferior isthmus in a Fontan patient using magnetic navigation

e r After classic Fontan operation, that is, atriopulmonary onnection, up to 50% of the patients develop atrial tachyardia (AT) during long-term follow-up. The majority of trial arrhythmias following the Fontan procedure are ATs elated to surgical incision or inferior isthmus-dependent utter. We report a 44-year-old man with recurrent AT. His original diagnosis was double inlet left ventricle with discordant ventricular arterial connection and pulmonary stenosis. At age 21 years, he underwent a Fontan operation with an atriopulmonary connection (using a homograft) and patch closure of the AV valve connecting the right atrium (RA) to the left ventricle following a palliative left BlalockTaussig shunt at the age of 12 years. In addition, 2 device closures (Amplatzer, 6 and 15 mm, respectively) were performed for residual patch leaks. (The dotted red line in Figure A depicts the patch across the right-sided AV valve. Note the 2 closure devices.) A single-lead atrial pacemaker had also been implanted for sinus node dysfunction. A 3-dimensional electroanatomic mapping system (Carto-RMT, Biosense-Webster, Diamond Bar, CA) was used in combination with the remote magnetic navigation system (Niobe, Stereotaxis Inc, St Louis, MO) for mapping and ablation of AT. The activation in the electroanatomic apping and entrainment mapping demonstrated that the achycardia was isthmus dependent. Radiofrequency energy as delivered to the RA-sided inferior isthmus (the blue line n Figure 1) without effect, and hence the decision to aproach the ventricular side of the inferior isthmus (the arrow n Figure 1; the remaining myocardium excluded from the

Successful ablation of sinus node reentrant tachycardia using remote magnetic navigation system

Ablation of sinus node reentrant tachycardia (SNRT) may be difficult with risk of sinus node injury by using conventional catheters. We report successful ablation of SNRT by using remote magnetic navigation system (Stereotaxis).

Remote magnetic versus manual catheters: evaluation of ablation effect in atrial fibrillation by myocardial marker levels

BackgroundA remote magnetic navigation (MN) system is available for radiofrequency ablation of atrial fibrillation (AF), challenging the conventional manual ablation technique. The myocardial markers were measured to compare the effects of the two types of MN catheters with those of a manual-irrigated catheter in AF ablation.MethodsAF patients underwent an ablation procedure using either a conventional manual-irrigated catheter (CIR, n = 65) or an MN system utilizing either an irrigated (RMI, n = 23) or non-irrigated catheter (RMN, n = 26). Levels of troponin T (TnT) and the cardiac isoform of creatin kinase (CKMB) were measured before and after ablation.ResultsMean procedure times and total ablation times were longer employing the remote magnetic system. In all groups, there were pronounced increases in markers of myocardial injury after ablation, demonstrating a significant correlation between total ablation time and post-ablation levels of TnT and CKMB (CIR r = 0.61 and 0.53, p < 0.001; RMI r = 0.74 and 0.73, p < 0.001; and RMN r = 0.51 and 0.59, p < 0.01). Time-corrected release of TnT was significantly higher in the CIR group than in the other groups. Of the patients, 59.6% were free from AF at follow-up (12.2 ± 5.4 months) and there were no differences in success rate between the three groups.ConclusionsRemote magnetic catheters may create more discrete and predictable ablation lesions measured by myocardial enzymes and may require longer total ablation time to reach the procedural endpoints. Remote magnetic non-irrigated catheters do not appear to be inferior to magnetic irrigated catheters in terms of myocardial enzyme release and clinical outcome.