Remote Magnetic Navigation Research Articles

Transseptal puncture via a superior access as an alternative to the conventional femoral route

IntroductionCongenital heart disease (CHD) patients represent a challenge for ablation procedures and may require unusual procedural techniques. An example is the absence of femoral venous accesses that makes a conventional TSP approach impossible. ObjectiveWe report a series of 6 procedures in which transseptal puncture (TSP) was performed via the jugular vein approach using a radiofrequency (RF) needle visualized on the electroanatomical mapping (EAM) system. Methods and resultsAblation procedures for either atrial fibrillation and left-sided atrial tachycardia were performed in 3 patients (54-53-29years) with congenital disease and blocked femoral approach (interrupted inferior vena cava with azygos continuation (2 ​pts), bilaterally blocked femoral venous access due to previous interventions (1 ​pt)). Using the right jugular(n ​= ​5) and left jugular vein(n ​= ​1) we performed a single TSP using a combination of fluoroscopy and EAM guidance with 3D visualisation of the RF needle tip. The main difficulties encountered and solutions are described. In four procedures, remote magnetic navigation was subsequently used. Left atrial access was gained in all cases without complications. Overall procedural time was 373 [321–458] min, with a median fluoroscopy time of 16 [8–26] min and median radiation dose of 1442 [348–3007] μGym2. ConclusionTSP via superior access is feasible in patients with complex congenital cardiac anatomy. Pre-procedural imaging, EAM and the 3D visualisation of the transseptal needle are tools that greatly facilitate the procedural success.

Treatment of symptomatic atrial tachycardia in complex anatomic conditions: use and outcome of ablation in patients after damus-kaye-stansel surgery

Abstract Funding Acknowledgements Type of funding sources: None. Background Atrial tachycardias (AT) are amongst the most frequent complications in adult patients with congenital heart disease (ACHD). Their incidence mainly depends on age and complexity of underlying defect. AT has a marked impact on morbidity and mortality and is associated with sudden cardiac death particularly in complex ACHD patients. The arrhythmic substrate can be variable from re-entry to multifocal resulting in demanding requirements for electrophysiologic ablation procedures (EP) and thus, relatively high rates of recurrence. Methods and results Retrospective analysis of ACHD patients with prior Damus-Kaye-Stansel (DKS) surgery treated at one of the largest specialized tertiary centers for ACHD patients worldwide. Analysis focussed on occurrence of AT, respective treatment and outcome of EP. Over a median observation time of 15 years, 13 patients with prior DKS surgery and complex congenital heart defects of different types but uniformly Fontan circulation, were identified (median age 22.0 years (IQR 20.5 – 25.5), 76.9% male, 92.3% NYHA Class I, median systemic ventricular ejection fraction 58.5%, 69.2% extracardiac tunnel). Seven patients (53.8%) presented with symptomatic AT (median cyclic length 440 ms (IQR 360.0 – 517.5)). Of these, six patients underwent EP. Median procedure time was 180.5 min (IQR 160.8 – 274.5), median fluoroscopy time 1.56 min (IQR 0.51 – 4.73) and radiofrequency time 851 sec (265.0 -2005.0). Remote magnetic navigation was used to access ablation site through a retrograde access via the aortic as well as the neo-aortic valve. Three-dimensional image integration aided in mapping and ablation. Throughout the procedure as well as in follow-up visits, no reportable complications were observed. After a mean of 1.5 procedures, all analysed patients stayed complaint-free throughout a median time-interval of 13 months. Conclusion AT are frequent in complex univentricular situations after Damus-Kaye-Stansel surgery (53.8%). Although more than one procedure (mean 1.5) was necessary to achieve satisfactory results even in experienced hands, EP appears to be an appropriate treatment strategy in this young and otherwise healthy patient cohort. According to our analysis, EP is feasible and safe in centers with knowledge of specific anatomic characteristics of congenital heart disease and when the appropriate technical infrastructure is present. Access to ablation site was performed by remote magnetic navigation in the majority of procedures. The floppy catheter was navigated through the neo-aortic as well as through the aortic valve without observable peri- or postinterventional complications. Mapping with three-dimensional image integration facilitated EP and led to a relatively low radiation exposure with the known benefits for the patient as well as for the healthcare professionals involved in the procedure. Abstract Figure.

Remote magnetic navigation shows superior long-term outcomes in pediatric atrioventricular (nodal) tachycardia ablation compared to manual radiofrequency and cryoablation

Abstract Funding Acknowledgements Type of funding sources: None. Introduction – Catheter ablation (CA) is a first-choice treatment for tachyarrhythmia in pediatric patients. The currently available CA techniques differ in manner of catheter steering technique and energy sources. There are no large studies comparing long-term outcomes between the available CA techniques in pediatric patients with atrioventricular reentry (also known as accessory pathway mediated) tachycardia (AVRT) or atrioventricular nodal reentry tachycardia (AVNRT) mechanisms. Objective – The aim of this study was to compare procedural parameters and outcomes of remote magnetic navigation-guided radiofrequency (RF) ablation (RMN), manual-guided RF ablation (MAN) and manual-guided cryoablation (CRYO). Methods – This single-center, retrospective study included all first consecutive CA procedures for AVRT or AVNRT mechanisms performed in pediatric patients with no structural heart disease from January 2008 until June 2019. Three study groups were defined by the ablation technique used: RMN, MAN or CRYO. Primary outcome was recurrence of tachyarrhythmia and/or pre-excitation on ECG. Baseline clinical parameters, procedure times and complication rates were also evaluated. Results – In total, we included 223 patients, aged 13.8 ± 2.8 years, with a mean weight of 55.6 ± 14 kilograms. In total, 108 procedures were performed using RMN, 76 using MAN and 39 using Cryo. RMN had the lowest recurrence rates at a mean follow-up of 5.5 ± 2.9 years (AVRT ablation: 4% vs. 16% vs. 55%, P < 0.001; AVNRT ablation: 8% vs. 8% vs. 36%, P = 0.008; for RMN vs. MAN vs. CRYO respectively). In AVRT ablation, procedure and fluor times were comparable between groups. However, in AVNRT ablation, RMN and MAN had significantly lower fluoroscopy times compared to Cryo (10 (IQR 7-14) vs. 9 (IQR 6-26) vs. 15 (IQR 10-22) minutes respectively, P = 0.040). Moreover, procedure times were shortest in MAN and second in RMN ablation (101 (IQR 87-121) vs. 88 (IQR 62-99) vs. 120 (IQR 88-143) minutes respectively, P = 0.018). We observed minor complications in 3 patients (1%), which were comparable between groups and no major complications. Conclusion – In pediatric patients with no structural heart disease who underwent their first AV(N)RT ablation, RMN has the most favorable long-term outcomes, in addition to favorable fluoroscopy and procedure times. Abstract Figure. AVRT and AVNRT ablation recurrence rates

Outcomes of manual versus remote magnetic navigation for catheter ablation of ventricular tachycardia: a systematic review and updated meta-analysis.

Ventricular tachycardia (VT) ablation is a complex procedure that requires remarkable catheter manipulation skill, great mapping accuracy and catheter stability, and can expose patients to serious complications. Magnetic navigation system (RMN)-guided ablation and contact force-sensing (CFS) catheters have the potential to overcome these obstacles. We performed a systematic review and updated meta-analysis of all available studies evaluating the outcomes of VT ablation by using RMN-guided compared to manual navigation (MAN)-guided, with and without CFS catheters. MEDLINE/PubMed, Cochrane, and Google Scholar were searched for randomized controlled trials (RCT) or observational studies with multivariate adjustment comparing RMN-guided versus MAN-guided VT ablation. Thirteen studies enrolling 1348 patients (656 RMN-guided vs. 692 MAN-guided) were included. CFS catheter were used in 14% of MAN-guided patients. In comparison to MAN-guided and CFS-guided, RMN-guided VT ablation was associated with a significant higher acute ablation success (OR 2.32, 1.66-3.23 and OR 2.91, 1.29-6.53, respectively) but similar results in term of long-term VT recurrence (OR 0.75, 0.56-1.01 and OR 0.79, 0.27-2.36, respectively). RMN-guided showed a better safety profile (for all complications, OR 0.52, 0.34-0.81) and allowed a significant x-ray reduction compared to MAN-guided (OR 0.21, 0.14-0.32) and CFS-guided VT ablation (OR 0.23, 0.11-0.52, all 95% CI). RMN-guided was superior to MAN-guided and CFS-guided VT ablation in term of acute ablation success, all complications endpoint, and reduction of fluoroscopy exposure, but did not reduce long-term VT recurrence. Large prospective multicenter randomized trials are needed to confirm these findings.

Remote magnetic navigation for heart rhythm disturbances treatment in patients after surgical correction of congenital heart disease

The prevalence of congenital heart diseases is nine persons per 1000. Sometimes, congenital heart disease needs surgical correction. The long-term postoperative period is often associated with complex heart rhythm disturbances like ectopic or re-entry tachycardia. These cases, in combination with difficult anatomy, results in challenges during interventional treatment. Catheter ablation has been demonstrated as safe and effective in different types of arrhythmia treatments in such patients, including paediatric cohorts. Despite these facts, several important problems regarding using current technologies are still unresolved. Remote magnetic navigation showed good results regarding localisation of arrhythmogenic zones during treatment of complex heart rhythm disturbances. The objective of the present article is to review recently published data in this area and experience of Meshalkin National Medical Research Center in heart rhythm disturbances treatment using remote magnetic navigation in patients after surgical correction of congenital heart disease. Received 28 September 2020. Revised 25 December 2020 г. Accepted 30 December 2020. Funding: The study did not have sponsorship. Conflict of interest: Authors declare no conflict of interest. Author contributionsConception and study design: A.B. Romanov, A.M. ChernyavskiyDrafting the article: V.V. Beloborodov, А.V. Ponomarenko, E.А. MorzhanaevCritical revision of the article: A.B. Romanov, А.V. Ponomarenko, I.L. Mikheenko, E.А. Morzhanaev, A.G. Filippenko, A.M. ChernyavskiyFinal approval of the version to be published: V.V. Beloborodov, N.А. Yelemessov, А.V. Ponomarenko, E.А. Morzhanaev, A.G. Filippenko, I.L. Mikheenko, A.M. Chernyavskiy, A.B. Romanov

Transseptal puncture through the atrial septal occluder in patient with atrial fibrillation for guided radiofrequency ablation procedure using remote magnetic navigation: A clinical case

Access to the left atrium during transseptal puncture for radiofrequency ablation in patients with atrial fibrillation (AF) and implanted atrial septal occluder can be challenging. This is particularly true when the occluder covers the entire septum and there is no ideal puncture site. This might lead to potential difficulties in arrhythmia treatment.A 59-year-old patient with drug refractory AF, a dilated left atrium, and an implanted atrial septal occluder underwent double transseptal puncture through atrial septal occluder with subsequent pulmonary vein isolation using remote magnetic navigation. The effectiveness of the manipulation was confirmed by intraoperative stimulation from the Lasso catheter and by Holter monitoring data post-operation. It was revealed that the patient had sinus rhythm and no complications occurred. There were no shunts at the occluder level on transthoracic echocardiography, and there were no atrial tachyarrhythmias during the nine-month follow up period without antiarrhythmic drugs. The presented clinical case demonstrates the safety and efficacy of transseptal puncture through an implanted occluder in the interatrial septum to perform re-ablation using robotic magnetic navigation in a patient with AF.Received 21 October 2020. Revised 20 November 2020. Accepted 25 November 2020.Funding: The work is supported by a grant of the President of the Russian Federation No. МД-1997.2020.7.Conflict of interest: Authors declare no conflict of interest.Author contributions Drafting the article: А.V. Ponomarenko, R.E. Zhizhov, V.V. Baranova, E.V. Fisher, A.B. RomanovLiterature review: А.V. Ponomarenko, R.E. Zhizhov, V.V. Baranova, E.V. FisherIllustrations: А.V. Ponomarenko, A.B. RomanovCritical revision of the article: А.V. Ponomarenko, R.E. Zhizhov, V.V. Baranova, A.M. Chernyavskiy, A.B. RomanovSurgical treatment: N.А. Yelemessov, I.S. Peregudov, V.V. Shabanov, A.B. RomanovFinal approval of the version to be published: А.V. Ponomarenko, N.А. Yelemessov, I.S. Peregudov, R.E. Zhizhov, V.V. Baranova, E.V. Fisher, V.V. Shabanov, A.M. Chernyavskiy, A.B. Romanov

Prognostic value of time dependent voltage abatement during remote magnetic navigation guided ablation in idiopathic right ventricular outflow tract arrhythmias

Kontext: NaĹĄĂ­m cĂ­lem bylo zjistit, zda časově zĂĄvislĂŠ snĂ­ĹženĂ­ voltĂĄĹže (dV/dt) na komorovĂ˝ch elektrogramech (EGM) během katetrizačnĂ­ ablace idiopatickĂ˝ch arytmiĂ­ z vĂ˝tokovĂŠho traktu pravĂŠ komory (right ventricular outflow tract, RVOT) s pouĹžitĂ­m systĂŠmu Stereotaxis Niobe II představuje účinnĂ˝ ukazatel dlouhodobĂŠ Ăşspěšnosti vĂ˝konu. Metody: Do studie bylo zařazeno 26 po sobě nĂĄsledujĂ­cĂ­ch pacientĹŻ s akutnĂ­ Ăşspěšnou ablacĂ­ RVOT pro předčasnĂŠ komorovĂŠ stahy (premature ventricular contractions, PVC) a/nebo komorovĂŠ tachykardie (KT) s pĹŻvodem nejspĂ­ĹĄe v RVOT. PozdnĂ­ Ăşspěšnost byla definovĂĄna jako vymizenĂ­ komorovĂ˝ch ektopiĂ­ z RVOT po tříměsíčnĂ­m sledovĂĄnĂ­ bez antiarytmik (antiarrhythmic drug, AAD). VĂ˝sledky: Po tříměsíčnĂ­m sledovĂĄnĂ­ vymizely symptomy i arytmie u 20 (skupina 1) z 26 pacientĹŻ (77 %), přičemĹž k recidivě doĹĄlo u ĹĄesti pacientĹŻ (23 %) (skupina 2). Během RF ablace byl "warming up" fenomĂŠn pozorovĂĄn u 85 %, resp. 83,33 % pacientĹŻ (p = 0,46) po prĹŻměrnĂŠ době (dt 2) 4,72 ± 9,42, resp. 10,75 ± 11,34 s (p = 0,045). Doba od zahĂĄjenĂ­ aplikace RF energie (t0) do vĂ˝znamnĂŠho snĂ­ĹženĂ­ voltĂĄĹže (> 90 %) nebo obrĂĄcenĂ­ polarity EGM (t1) u obou skupin činila 9,11 ± 5,11, resp. 32,16 ± 10,33 (p = 0,00006). Hodnota dV/dt1 byla 95,44 ± 87,6, resp. 23,5 ± 16,97 μV/s (p = 0,024). ZĂĄvěr: Časově zĂĄvislĂŠ snĂ­ĹženĂ­ voltĂĄĹže na komorovĂŠm EGM spolu s dobou od zahĂĄjenĂ­ RF ablace do vĂ˝znamnĂŠho snĂ­ĹženĂ­ voltĂĄĹže (> 90 %) nebo obrĂĄcenĂ­ polarity EGM a dobou od aplikace RF energie do vzniku "warming up" fenomĂŠnu představujĂ­ moĹžnĂŠ prediktory dlouhodobĂŠ Ăşspěšnosti RF ablace idiopatickĂ˝ch arytmiĂ­ vychĂĄzejĂ­cĂ­ch z RVOT. © 2021, ČKS.

Modeling Electromagnetic Navigation Systems

Remote magnetic navigation is used for the manipulation of untethered micro and nanorobots, as well as tethered magnetic surgical tools for minimally invasive medicine. Mathematical modeling of the magnetic fields generated by magnetic navigation systems is a fundamental task in the control of such tools for biomedical applications. In this article, we describe and compare several existing and newly developed methods for representations of continuous magnetic fields using interpolation in the context of remote magnetic navigation. Clinical-scale electromagnetic navigation systems feature nonlinear magnetization and magnetization interactions between electromagnets, which renders accurate magnetic field modeling challenging. We first introduce a method that can adapt existing linear models to correct for nonlinear magnetization, with similar performance to the current state-of-the-art nonlinear model. Furthermore, we present a method based on convolutional neural networks.

Abstract 15656: Manual vs Remote Magnetic Navigation for Ventricular Tachycardia Ablation: A Meta-analysis

Introduction: The role of remote magnetic navigation (RMN) for ventricular tachycardia (VT) ablation is not well established. In this meta- analysis, we aim to evaluate the safety and efficacy of RMN vs manual navigation (MAN) for VT ablation. Methods: A comprehensive literature search in PubMed, Google Scholar and Cochrane Review from inception till November 9th, 2019 was performed. Studies reporting clinical outcomes comparing MAN vs RMN were included. Two investigators independently extracted the data and individual quality assessment was performed. Results were expressed as odds ratio (OR) for dichotomous outcomes and mean differences (MD) for continuous variables with 95% confidence intervals (CI). Results: Eight studies including a total of 861 patients (475 in RMN arm and 386 in MAN arm) were included in the final analysis. VT recurrence was significantly lower with RMN compared with MAN (OR 0.65, 95% CI 0.48-0.88, p= 0.005). Acute procedural success was significantly higher with RMN (OR 2.21, 95% CI 1.51-3.23, p < 0.0001). Total procedure time [MD -8.83, 95% CI -17.72- 0.05, p=0.05], fluoroscopy time [MD -10.24, 95% CI -12.28- -8.19, p= 0.00001), and complications [OR 0.36, 95% CI 0.18- 0.72, p= 0.003] were significantly lower in RMN compared to MAN. Conclusion: Results of our meta-analysis indicate that RMN is safer and more effective than MAN in patients with VT undergoing ablation. Further, randomized studies are needed to validate these findings.

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.

Radiofrequency atrial fibrillation ablation with irrigated tip catheter using remote magnetic navigation compared with conventional manual method.

Studies comparing manual catheter navigation (MCN) to remote magnetic navigation (RMN) for atrial fibrillation (AF) ablation showed variable results. The aim of this meta-analysis is to compare the safety and clinical outcomes of AF radiofrequency (RF) ablation using MCN versus RMN with irrigated tip catheters. Medline and the Cochrane Central Register of Controlled Trials (CENTRAL) were queried from inception through January 2019. Studies comparing safety and clinical outcomes of AF ablation with RF using MCN versus RMN with irrigated tip catheters were included. Random effects meta-analysis was used to pool outcomes across studies. Study endpoints included freedom of AF at the end of the study, procedure total time, fluoroscopy time, and complications. A total of 14 studies (3 controlled non-randomized trials, 1 prospective observational, and 10 retrospective observational studies) involving 3375 patients (1871 in MCN and 1504 in RMN) were included in this meta-analysis. There was no significant difference between the two groups in terms of freedom of AF (OR 1.08, 95% CI 0.82-1.42, p = 0.52). The MCN group was associated with shorter procedure time (mean difference in minutes - 50.39, 95% CI - 67.99 to - 32.79, p < 0.01), longer fluoroscopy time (mean difference in minutes 18.01, 95% CI 10.73-25.29, p < 0.01), and higher complication rate (OR 2.18, 95% CI 1.24-3.82, p < 0.01). AF ablation utilizing MCN was associated with similar efficacy to RMN but with higher complication rates. Although the procedure time was shorter with MCN, the fluoroscopy time was more prolonged. Randomized clinical studies are needed to further verify these results.

Pulmonary Artery Denervation for Patients With Residual Pulmonary Hypertension After Pulmonary Endarterectomy

BackgroundPulmonary artery denervation (PADN) procedure has not been applied to patients with residual chronic thromboembolic pulmonary hypertension (CTEPH) after pulmonary endarterectomy (PEA). ObjectivesThis study sought to assess the safety and efficacy of PADN using remote magnetic navigation in patients with residual CTEPH after PEA. MethodsFifty patients with residual CTEPH despite medical therapy at least 6 months after PEA, who had mean pulmonary artery pressure ≥25 mm Hg or pulmonary vascular resistance (PVR) > 400 dyn‧s‧cm−5 based on right heart catheterization were randomized to treatment with PADN (PADN group; n = 25) using remote magnetic navigation for ablation or medical therapy with riociguat (MED group; n = 25). In the MED group, a sham procedure with mapping but no ablation was performed. The primary endpoint was PVR at 12 months after randomization. Key secondary endpoint included 6-min walk test. ResultsAfter PADN procedure, 2 patients (1 in each group) developed groin hematoma that resolved without any consequences. At 12 months, mean PVR reduction was 258 ± 135 dyn‧s‧cm−5 in the PADN group versus 149 ± 73 dyn‧s‧cm−5 in the MED group, mean between-group difference was 109 dyn‧s‧cm−5 (95% confidence interval: 45 to 171; p = 0.001). The 6-min walk test distance was significantly increased in the PADN group as compared to distance in the MED group (470 ± 84 m vs. 399 ± 116 m, respectively; p = 0.03). ConclusionsPADN in patients with residual CTEPH resulted in substantial reduction of PVR at 12 months of follow-up, accompanied by improved 6-min walk test.

P565First characterization of high-power short-duration radiofrequency ablation with remote magnetic navigation assistance

Abstract Funding Acknowledgements MEYS- CR (ref#LQ1605 and LM2015062) Background/Introduction High-power short-duration (HPSD) radiofrequency (RF) ablation relies on the application of intense thermal fields for a carefully restricted time, in order to quickly obtain deep but precise lesions that spare the structures surrounding the heart. The approach is still under evaluation across different therapies and catheter technologies. To the present day there is no available characterization of HPSD ablation supported by remote magnetic navigation (RMN). Purpose To describe the safety issues regarding HPSD ablation in atria and ventricles with RMN systems, while characterizing the thermal lesion size and continuity in an acute closed-chest swine model. Methods The animal trial was divided in two arms (left ventricular and atrial). 10 female large white pigs (6-month-old weight 55-65 kg) were employed in each arm. Endocardial electroanatomical mapping and ablation were performed with RMN assistance to provide stable contact and flexible maneuvering. The ventricular cohort was divided in 5 power settings (30-40-50-60-70W). Multiple RF applications (10 ca./animal) were delivered until a pop occurred or up to 60s. In the atrial cohort the animals were divided by a combination of power/application time (50W/20s – 70W/10s – 90W/4s). Intracaval right atrial ablation lines and postero-lateral left atrial lines were performed in a point-by-point fashion (ca. 4mm distance). Irrigation rate was 30ml/min. The ventricular lesions were measured via software after 9.4T MRI of fixed hearts. The atrial lesions were measures during pathological examination after explanation. Results In the ventricular arm, we obtained a safety calibration curve linking the imposed power setting to the maximal time of application. The time before a pop decreased non-linearly from 60s down to 17.69 ± 8.21 s at 70W. No statistically significant differences were observed when comparing lesions depth, width and volume among the selected power settings. In the atrial arm we observed on the post-ablation maps a significant decrease of intracaval lesions (i.e. area with bipolar voltage &amp;lt;1.5mV) width (17.57 ± 1.89 mm for 50W/4s down to 10.16 ± 1.56 mm for 90W/4s). Pericardial, pleural and aortic damages were visible across all the employed settings, with less pronounced alterations for 90W/4s. Transmural lesions were visible both on the right and left atrium, with evident gaps for 50W/20s. Conclusion The presented work assesses for the first time the safety limits of HPSD ablation on healthy ventricular myocardium. We provide a calibration curve for faster RF ablation with comparable lesion features. Furthermore, we expanded the previously reported application in the atrium adding the benefits of stable controlled contact provided by RMN systems. We highlighted the benefits (e.g. faster, continuous and localized lesion formation) and risks for peripheral structures using HPSD ablation for supraventricular tachycardia interventions. Abstract Figure.

P355Complete non-inducibility after radiofrequency ablation for electrical storm improves survival rates

Abstract Background Electric storm is a life threatening condition, that can complicate multiple cardiac pathologies and is associated with high mortality. Catheter ablation has been shown to reduce ventricular tachycardia (VT) burden in patients with electrical storm but the optimal procedural endpoint and the therapeutic particularities required by different etiologies are still under debate. Purpose Our objective was to determine if there are any periprocedural factors that influence midterm outcomes. We also sought if there were any significant differences between the results for ischemic and nonischemic patients. Methods The study included 66 consecutive patients, mean age 60 years, 82% males, treated for electrical storm in our center with endocardial/endo-epicardial radiofrequncy catheter ablation (with or without remote magnetic navigation). Acute success was defined as elimination of the clinical tachycardia with complete non-inducibility (including ventricular fibrillation) or non-inducibility for monomorphic VT with programmed ventricular stimulation using up to 4 extrastimuli. Mean follow-up duration was 9.4 months and the type of recurrence was catalogued in 3 categories: initial VT (isolated), electric storm and other sustained VT. Results The overall acute success rate was 93%, complete non-inducibility was achieved in 64.5% and non-inducibility for monomorphic VT in 87.5% of the cases. Epicardial approach was used in 44% of the non-ischemic cases vs 10.5% of the ischemic ones (p = 0.005). There were no significant differences between complete noninducibility rates and recurrence/death rates of the ischemic vs nonischemic groups. Among the variables analysed for predicting noninducibility, only two reached statistical significance: mean QRS duration of the clinical tachycardia (160 ± 32 ms vs 240 ± 63.3ms, p = 0.02) and shortest RS complex (124 ± 14.7 ms vs 210 ± 12ms, p = 0.02). Recurrent ventricular arrhythmia occurred in 25% of the patients during follow up, from which: 27.2 % initial VT (isolated), 36.4% electric storm and 36.4% other sustained VT. Death rate was 10.6% (7 patients). Kaplan Meier plot showed that the lot with complete noninducibility after programmed ventricular stimulation had better survival rates (p = 0.01). Conclusions Ablative therapy had a good acute success rate, without significant differences between ischemic and noninschemic patients in our study. Complete noninducibility after programmed ventricular stimulation after ablation was associated with better survival rates. Unsuccessfull ablation is a predictor of inhospital death of these patients.

Procedural outcomes and learning curve of cardiac arrhythmias catheter ablation using remote magnetic navigation: Experience from a large-scale single-center study.

BackgroundRemote magnetic navigation (RMN)‐guided ablation has become an inspiring method of catheter ablation for tachyarrhythmias.HypothesisData from a large‐scale single center may provide further insight into the safety of and the learning curve for RMN‐guided ablation.MethodsA total of 1003 catheter ablation procedures using RMN for conditions including supraventricular ventricular tachycardia, atrial tachyarrhythmias, and premature ventricular contraction/ventricular tachycardia (PVC/VT) were retrospectively analyzed from an ablation registry. Procedural outcomes, including procedure time, mapping time, X‐ray time, and RF time, were assessed. The complications were classified into two categories: major and minor. A subanalysis was used to illustrate the learning curve of RMN‐guided ablation by assessing procedure time and total X‐ray time of 502 atrial fibrillation (AF) ablation procedures.ResultsAmong these procedures, 556 (55.4%) were AF and 290 (28.9%) were PVC/VT. Electrical pulmonary vein isolation was achieved in 99.0% of AF procedures, and acute success reached 90.3% in PVC/VT procedures. The overall complication rate was 0.5%. In the subanalysis of AF procedures, the overall procedure time and X‐ray time of procedures were short (125.9 ± 54.6 and 5.3 ± 3.9 minutes, respectively) and proceeded to decrease from the initial 30 procedures to about 300 procedures, where the learning curve reached plateau, demonstrating maximum procedure efficiency.ConclusionsRMN‐guided ablation is safe, as verified by very low overall complication rate and reduced X‐ray time. In our study, even the first AF procedures had a relatively low procedure time and total X‐ray time, and procedure efficiency improved during the learning curve.

A Magnetically Navigated Microcannula for Subretinal Injections.

Retinal disorders, including age-related macular degeneration, are leading causes of vision loss worldwide. New treatments, such as gene therapies and stem cell regeneration, require therapeutics to be introduced to the subretinal space due to poor diffusion to the active component of the retina. Subretinal injections are a difficult and risky surgical procedure and have been suggested as a candidate for robot-assisted surgery. We propose a different actuation paradigm to existing robotic approaches using remote magnetic navigation to control a flexible microcannula. A flexible cannula allows for high dexterity and considerable safety advantages over rigid tools, while maintaining the benefits of micrometer precision, hand tremor removal, and telemanipulation. The position of the cannula is tracked in real-time using near-infrared tip illumination, allowing for semi-automatic placement of the cannula and an intuitive user interface. Using this tool, we successfully performed several subretinal injections in ex-vivo porcine eyes under both microscope and optical coherence tomography visualization.

Introducing a novel catheter-tissue contact feedback feature in robotic navigated catheter ablation: Utility, feasibility, and safety.

BackgroundThe quality of catheter–tissue contact is one of the most important determinants of catheter ablation (CA) success. The absence of catheter–tissue contact feedback has been regarded a major limitation of remote magnetic navigation (RMN)–guided CA. The e-Contact module (ECM) is a novel feature designed for RMN that measures the quality of catheter–tissue contact.ObjectiveThe purpose of this study was to describe the first clinical experience with this feature and to test its effect on procedural parameters and interference with other ablation equipment during CA procedures as well as its safety.MethodsThis was a prospective, single-center, 2-phase study investigating ECM use during complex RMN procedures in 30 patients. Impact of ECM on procedural parameters was evaluated in the feasibility phase (FP), and its interference with other equipment was tested in the interference phase (IP) using pacing maneuvers at 3 randomly selected right atrial sites. Intracardiac electrograms were evaluated for disturbances by 2 independent electrophysiologists.ResultsFor FP, mean procedural time was 162 ± 66 minutes, fluoroscopy time 21 ± 9 minutes, and ablation time 34 ± 21 minutes. For IP, no significant differences in pacing capture or thresholds were found (ECM– vs ECM+: site 1: 2.05 vs 2.21 mA; P = .320; site 2: 2.15 vs 2.12 mA; P = .873; site 3: 2.51 vs 2.50 mA; P = .976). Electrogram disturbances did not significantly differ between ECM– and ECM+. No adverse events were reported.ConclusionThe ECM is a novel catheter–tissue contact technology designed for RMN-guided CA. Our study suggests that this feature is feasible and does not interfere with other electrophysiology equipment while maintaining an excellent safety profile.

Robotics for catheter ablation of cardiac arrhythmias: Current technologies and practical approaches.

Robotic technology has emerged as an important tool to facilitate catheter ablation of arrhythmias. Robotic cardiac electrophysiology technology includes remote magnetic navigation and manual robotic navigation. Robotics can confer advantages with respect to ease of catheter manipulation in anatomically challenging spaces, minimization of fluoroscopic exposure to both patients and operators, and reduction in operator fatigue. This review provides a comprehensive summary of robotic electrophysiology technology, its practical applications and its safety and efficacy for targeting cardiac arrhythmias.

P1732 Congenital absence of the inferior vena cava: challenge for catheter ablation of arrhythmias via the femoral vein approach

Abstract Introduction Congenital anomalies of the inferior vena cava (IVC) are a well described entity. These anomalies include complete absence, partial absence or duplication of the IVC. They are seen more frequently in those with other congenital cardiac anomalies (0.6%–2%). This congenital condition can be discovered incidentally, or due to symptoms of associated congenital heart disease, asplenia, polysplenia, congenital kidney anomalies or deep venous thrombosis. Case report We report the case of a 48 years old man scheduled for pulmonary vein isolation due to persistent atrial fibrillation resistant to antiarhythmic drugs, symptomatic for palpitations and dyspnea on exertion. Transthoracic ecgocardiography showed mild left atrium enlargement, normal systolic LV function and no significant valve disease. The transoesophageal echocardiography revealed dilation of the left atrium and absence of thrombus in the left atrium or left appendage. Multi-slice spiral thoracic computed tomography (MSCT) was also performed before the procedure and revealed absence of the inferior vena cava and significant dilation of the azygos and hemiazygos veins with subsequent drainage into the superior vena cava. Abdominal CT showed also partial situs inversus. Pulmonary vein isolation (PVI) through femoral vein approach was cancelled and the patient was scheduled for remote magnetic navigation PVI through arterial approach. Conclusions Whether the absence of the IVC is an embryonic anomaly or the result of perinatal thrombosis with regression and subsequent congenital absence of the IVC, absence of the IVC creates difficulties for catheter ablation of arrhythmias via the femoral vein approach.

Strategy of catheter ablation for para-Hisian premature ventricular contractions with the assistance of remote magnetic navigation.

Catheter ablation of frequent para-Hisian premature ventricular contractions (PH-PVCs) is considered to be challenging. The purpose of this study was to evaluate the strategy, potential technical advantages, and clinical outcomes of remote magnetic navigation (RMN) in the ablation of PH-PVCs. Fifteen consecutive patients with PH-PVCs were included in this study. Electrical mapping was initially performed in the right ventricular septum by manipulating the RMN catheter with a "U-curve." In the case of no optimal ablation site or ablation failure, the ablation catheter was directed to the left ventricular (LV) septum through a transseptal approach for further mapping and ablation by manipulating the RMN catheter with a "reverse S-curve." Nine of 15 patients were submitted to ablation on the right side. However, ablation success was only achieved in only three (33%) cases. Of the other 12 patients, 11 underwent LV mapping and ablation. In this subset, 9 of 11 (82%) PH-PVCs were totally eliminated on the left side. Overall, RMN-guided mapping and ablation successfully eliminated 12 (80%) of 15 idiopathic PH-PVCs. During follow-up, the reoccurrence of PVCs was reported in 1 (8%) of 12 patients. No atrioventricular block was observed during or after the procedure. RMN-guided catheter ablation for PH-PVCs is effective and safe in unselected patients. Due to the excellent reachability and contact with special morphologies of the RMN catheter on both sides of the ventricular septum, RMN can be considered an effective approach for frequent PH-PVCs.