Biomedical subjects

Matthias Antz

Publications and source records attributed to Matthias Antz.

At least 19 recordsLinked to original sources

PubMed2007

Remote-controlled catheter ablation of accessory pathways: results from the magnetic laboratory.

AIMS: This study evaluates feasibility, safety, and efficacy of magnetic remote-controlled accessory pathway (AP) ablation. METHODS AND RESULTS: The novel magnetic navigation system (MNS) (Niobe, Stereotaxis) creates a steerable magnetic field (0.08 T) controlling the distal magnetic tip of an ablation catheter. In conjunction with a catheter advancer system (Cardiodrive, Stereotaxis) remote catheter ablation is enabled. Conventional electrophysiology study identified AP conduction in 59 patients (37 males, 36+/-14 years, 60 APs). First generation 1-magnet tip (1-M) (group I, n=18), second generation bipolar 3-magnet tip (3-M) (group II, n=27), and third generation quadripolar 3-magnet tip catheters (3-M quad.) (group III, n=14) were used for magnetic remote-controlled ablation. Successful AP ablation was achieved in 67% (group I), 85% (group II), and 92% (group III). A significant decrease of median [IQR: Q1-Q3] fluoroscopy time and dosage was observed: 21.2 [12.1-33.8] min, 1110 [395-3234] microGym2 (group I); 6.5 [4.4-15.4] min, 290 [129-489] microGym2 (group II), and 4.9 [3.4-8.0] min, 129 [74-270] microGym2 (group III). Mean procedure time (217+/-67 min; 182+/-68 min, and 172+/-90 min) significantly decreased in group III. Median number [Q1-Q3] of radiofrequency current applications in groups I, II, and III was 4 [2-9], 4 [2-6], and 2 [2-4], respectively. No complications occurred. CONCLUSION: Remote AP ablation is safe and feasible using the novel MNS. Introduction of the 3-magnet quadripolar ablation catheter significantly improved the efficacy of the procedure.

Adult↗

PubMed2006

Catheter ablation of anteroseptal accessory pathway in the non-coronary aortic sinus.

We report a patient with atrioventricular reentrant tachycardia (AVRT) with bidirectional conduction over an anteroseptal accessory pathway (AP) who underwent successful ablation in the non-coronary aortic sinus (AS). In three previous attempts, the intracardiac recordings showed an anteroseptal AP with antegrade and retrograde conduction that failed to be ablated in spite of radiofrequency (RF) applications from the right and left anteroseptal regions. During the study, the earliest atrial activation during tachycardia was recorded in the non-coronary AS preceding the atrial activation at the His bundle (HB) region by 24 ms, and the anteroseptal AP was successfully blocked by one single ablation in the non-coronary AS. These data strongly suggest that careful mapping of an anteroseptal AP in the non-coronary AS may provide an alternative ablation approach in patients with previously failed ablation.

Bundle of His↗

PubMed2006

A single pulmonary vein as electrophysiological substrate of paroxysmal atrial fibrillation.

INTRODUCTION: It has been demonstrated that pulmonary veins (PVs) play an important role in initiation and maintenance of paroxysmal atrial fibrillation (AF). However, it is not clearly known whether a single PV acts as electrophysiological substrate for paroxysmal AF. METHODS AND RESULTS: This study included five patients with paroxysmal AF. All patients underwent complete PV isolation with continuous circular lesions (CCLs) around the ipsilateral PVs guided by a three-dimensional mapping system. Irrigated radiofrequency (RF) delivery was performed during AF on the right-sided CCLs in two patients and on the left-sided CCLs in three patients. The incomplete CCLs resulted in a change from AF to atrial tachycardia (AT), which presented with an identical atrial activation sequence and P wave morphology. Complete CCLs resulted in AF termination with persistent PV tachyarrhythmias within the isolated PV in all five patients. PV tachyarrhythmia within the isolated PV was PV fibrillation from the left common PV (LCPV) in two patients, PV tachycardia from the right superior PV (RSPV) in two patients, and from the left superior PV in one patient. All sustained PV tachyarrhythmias persisted for more than 30 minutes, needed external cardioversion for termination in four patients and a focal ablation in one patient. After the initial procedure, an AT from the RSPV occurred in a patient with PV fibrillation within the LCPV, and was successfully ablated. CONCLUSION: In patients with paroxysmal AF, sustained PV tachyarrhythmias from a single PV can perpetuate AF. Complete isolation of all PV may provide good clinical outcome during long-term follow-up.

Adult↗

PubMed2006

Ablation of atrial fibrillation in humans using a balloon-based ablation system: identification of the site of phrenic nerve damage using pacing maneuvers and CARTO.

Injury of the phrenic nerve during pulmonary vein isolation for the treatment of atrial fibrillation is a well-recognized complication, especially when performing ostial ablations or using balloon-based technologies. This report describes the exact anatomical location of phrenic nerve injury during an attempt of right superior pulmonary vein isolation using a balloon that delivered high intensity focused ultrasound. Electroanatomical three-dimensional CARTO (Biosense Webster, Diamond Bar, CA, USA) mapping of the superior caval vein, the right and left atrium, as well as the right superior pulmonary vein was performed in conjunction with meticulous phrenic nerve pacing maneuvers before and after ablation and showed that the nerve was damaged at the level of the antero-inferior ostium of the right superior pulmonary vein. Diaphragmatic denervation occurred despite using an oversized balloon fluoroscopically placed at the atrial side of the pulmonary vein ostium.

Atrial Fibrillation↗

PubMed2006

Focal atrial tachycardia originating from the non-coronary aortic sinus: electrophysiological characteristics and catheter ablation.

OBJECTIVES: We sought to investigate electrophysiological characteristics and catheter ablation in patients with focal atrial tachycardia (AT) originating from the non-coronary aortic sinus (AS). BACKGROUND: In patients with failed ablation of focal AT near the His bundle (HB) region, an origin from the non-coronary AS should be considered because of the close anatomical relationship. METHODS: This study included 9 patients with focal AT, in 6 of whom attempted radiofrequency (RF) ablation had previously failed. Activation mapping was performed during tachycardia to identify an earliest activation in the atria and the AS. The aortic root angiography was performed to identify the origin in the AS before RF ablation. RESULTS: Focal AT was reproducibly induced by atrial pacing. Mapping in atria demonstrated that the earliest atrial activation was located at the HB region, whereas mapping in the non-coronary AS demonstrated that an earliest atrial activation preceded the atrial activation at the HB by 12.2 +/- 6.9 ms and was anatomically located superoposterior to the HB in all 9 patients. Also, His potentials were not found at the successful site in the non-coronary AS in all 9 patients. The focal AT was terminated in <8 s in all 9 patients. Junctional beats and PR prolongation did not occur during RF application in all 9 patients. No complications occurred in any of the nine patients. All 9 patients were free of arrhythmias without antiarrhythmic drugs during a follow-up of 9 +/- 3 months. CONCLUSIONS: In patients with focal AT near the HB region, mapping in the non-coronary AS can improve clinical outcome.

Adult↗

PubMed2006

Transesophageal echocardiography: a screening method for pulmonary vein stenosis after catheter ablation of atrial fibrillation.

AIMS: Pulmonary vein (PV) stenosis has been described as a complication after catheter ablation of atrial fibrillation. The aim of the study was to investigate the diagnostic role of transesophageal echocardiography (TEE) in the assessment of PV stenosis. METHODS: Ninety-one patients (71 men, mean age 57+/-16years), initially treated by catheter ablation of atrial fibrillation, underwent re-ablation because of arrhythmia recurrences. PV angiograms and TEE were performed before the first and second ablation. PVs were analysed in an intraindividual comparison by measurements of mean and peak flow velocity and of velocity time integrals and diameters. PV angiograms served as standard for assessment of PV stenosis. RESULTS: Sixteen of 91 patients developed PV stenoses as a consequence of the first ablation (13 mild PV stenoses, 4 moderate PV stenoses). All patients with PV stenosis were asymptomatic. In moderate PV stenosis (50-70%) a significant increase of blood flow parameters, reduction of vessel diameter, inhomogeneous blood flow and aliasing were demonstrated by TEE. Using quantitative TEE criteria moderate PV stenosis could be identified with a sensitivity of 84% and specificity of 98%. Detection of mild PV stenosis (30-50%) is challenging (sensitivity of 48% and specificity of 75%). CONCLUSIONS: TEE identifies significant PV stenosis by assessment of flow characteristics and vessel diameter and can thereby be used as a follow-up tool after catheter ablation of atrial fibrillation.

Aged↗

PubMed2006

Substrate mapping vs. tachycardia mapping using CARTO in patients with coronary artery disease and ventricular tachycardia: impact on outcome of catheter ablation.

AIMS: For ablation of ventricular tachycardia (VT) in patients after myocardial infarction, a three-dimensional mapping system is often used. We report on our overall success rate of VT ablation using CARTO in 47 patients, with a subgroup analysis comparing VT mapping with the results of mapping that had to be performed during sinus rhythm or pacing (substrate mapping). METHODS AND RESULTS: A CARTO map was performed and VT ablation attempted using two strategies: Patients in the VT-mapping group had incessant VT (four patients) or inducible stable VT (18 patients) such that the circuit of the clinical VT could be reconstructed using CARTO. During VT, the critical area of slow conduction was identified using diastolic potentials and conventional concealed entrainment pacing. In contrast, patients in the substrate-mapping group had initially inducible VT. However, a complete VT map was not possible because of catheter-induced mechanical block (six patients) or because haemodynamics deteriorated during the ongoing VT (19 patients). Therefore, pathological myocardium was identified by fragmented, late- and/or low-amplitude (<1.5 mV) bipolar potentials during sinus rhythm or pacing, and the ablation site was primarily determined by pace mapping inside or at the border of this pathological myocardium. Acute ablation success in all patients with regard to non-inducibility of the clinical VT or any slower VT was 79% after a single ablation procedure, but increased to 95% after a mean of 1.2 ablation procedures. However, chronic success was 75%, when it was defined as freedom from any ventricular tachyarrhythmia (VT or VF) during a follow-up of 25+/-13 months. In the subgroup analysis, patients in the VT-mapping group were not significantly different from patients in the substrate-mapping group with regard to age (65+/-7 vs. 65+/-9 years), ejection fraction (30+/-7 vs. 30+/-8%), VT cycle length (448+/-81 vs. 429+/-82 ms), number of radiofrequency applications (17+/-9 vs. 14+/-6 applications), use of an irrigated tip catheter (23 vs. 32%), and ablation results. CONCLUSION: When using a CARTO-guided approach for VT ablation in patients with coronary artery disease, the freedom from any ventricular arrhythmia is high (75%), but leaves the patient at a 23% risk of developing fast VT/VF during follow-up. Mapping during sinus rhythm or pacing is as successful as mapping during VT.

Aged↗

PubMed2006

External and endoluminal analysis of left atrial anatomy and the pulmonary veins in three-dimensional reconstructions of magnetic resonance angiography: the full insight from inside.

INTRODUCTION: The detailed knowledge of the individual pulmonary vein (PV) anatomy may help to prevent serious complications during PV isolation (PVI). The purpose of this study was to determine the geometry of the PV ostia and their spatial relation to adjacent structures in external (ex 3D) and endoluminal (en 3D) three-dimensional reconstructions of magnetic resonance angiographies (MRAs). METHODS AND RESULTS: Ex 3D and en 3D of the left atrium (LA) and the PVs of 28 patients were calculated. Diameters and the shape of PV ostia were assessed. In addition, the distances between ipsilateral PV ostia, the LA isthmus line, the roof line and the distance between the left PV and the LA appendage (LAA) were measured. Both ex 3D and en 3D are useful tools to determine the dimensions and the geometry of PVs. En 3D facilitates the identification of common PV ostia (15/28 patients). In en 3D, ipsilateral PV ostia are separated by a narrow myocardial ridge of less than 4 mm in 19/38 PVs (mean 4.3 +/- 1 mm; 4.6 +/- 2 mm with ex 3D). LAA and the LPV ostia are separated by a ridge of less than 4 mm in 12/28 PVs measured with en 3D (4.8 +/- 2 mm; 6.4 +/- 2 mm with ex 3D). CONCLUSIONS: Both ex 3D and en 3D reconstructions of MRA precisely visualize the complex LA anatomy. Exact determination of PV ostial geometry is facilitated with en 3D and provides important anatomical information for the PVI strategy. According to our data, individual encircling of every PV is strongly discouraged.

Aged↗

PubMed2005

Electrophysiological findings during ablation of persistent atrial fibrillation with electroanatomic mapping and double Lasso catheter technique.

BACKGROUND: Pulmonary veins (PVs) can be completely isolated with continuous circular lesions (CCLs) around the ipsilateral PVs. However, electrophysiological findings have not been described in detail during ablation of persistent atrial fibrillation (AF). METHODS AND RESULTS: Forty patients with symptomatic persistent AF underwent complete isolation of the right-sided and left-sided ipsilateral PVs guided by 3D mapping and double Lasso technique during AF. Irrigated ablation was initially performed in the right-sided CCLs and subsequently in the left-sided CCLs. After complete isolation of both lateral PVs, stable sinus rhythm was achieved after AF termination in 12 patients; AF persisted and required cardioversion in 18 patients. In the remaining 10 patients, AF changed to left macroreentrant atrial tachycardia in 6 and common-type atrial flutter in 4 patients. All atrial tachycardias were successfully terminated during the procedure. Atrial tachyarrhythmias recurred in 15 of 40 patients at a median of 4 days after the initial ablation. A repeat ablation was performed at a median of 35 days after the initial procedure in 14 patients. During the repeat study, recovered PV conduction was found in 13 patients and successfully abolished by focal ablation of the conduction gap of the previous CCLs. After a mean of 8+/-2 months of follow-up, 38 (95%) of the 40 patients were free of AF. CONCLUSIONS: In patients with persistent AF, CCLs can result in either AF termination or conversion to macroreentrant atrial tachycardia in 55% of the patients. In addition, recovered PV conduction after the initial procedure is a dominant finding in recurrent atrial tachyarrhythmias and can be successfully abolished.

Adult↗

PubMed2005

Tissue velocity imaging during dobutamine stimulation for assessment of myocardial viability: segmental analysis in patients after myocardial infarction.

BACKGROUND: Dobutamine stress echocardiography (DSE) is an established method for the detection of viable myocardium, but evaluation of this method is subjective. Tissue velocity Imaging (TVI) allows quantitative analysis of regional myocardial wall motion by assessment of systolic myocardial velocities. The aim of this study was to evaluate the diagnostic value of DSE and TVI for detection of viable myocardium. METHODS: In 56 patients (58+/-12 years) with previous myocardial infarction (130+/-42 days, mean ejection fraction 42+/-15%) low-dose DSE was combined with analysis of peak systolic myocardial velocities (Vpeak) by TVI for assessment of myocardial viability. As reference served a follow-up echocardiography after successful revascularization (mean 91+/-3 days). RESULTS: Of a total of 896 segments 200 showed abnormal wall motion (31 mildly hypokinetic, 50 severely hypokinetic, 115 akinetic, 4 dyskinetic). In 125 of these 200 segments regional improvement of regional wall motion was observed (62.5% viable). An increase of Vpeak>1 cm/s during dobutamine stimulation allowed the identification of viable myocardium with a sensitivity of 82% and a specificity 82% (DSE: 77% and 80%). By receiver operating characteristic (ROC) curve analysis, a cut-off value of 1.0 cm/s was the best parameter to differ viable from nonviable myocardium (area under the curve 0.85; p<0.01; 95% CI 0.79 to 0.90). Improvement of global ejection fraction after revascularization (47+/-13%, p=0.11) corresponded with three TVI viable segments with a sensitivity of 92% and a specificity of 89% (p=0.012). CONCLUSIONS: TVI allows the identification of viable myocardium during dobutamine stimulation and enables a quantitative interpretation of DSE.

Cardiotonic Agents↗

PubMed2005

[Is an electrophysiological study always necessary before defibrillator implantation?].

An electrophysiological study (EPS) and a programmed ventricular stimulation (PVS) are strongly recommended and clearly indicated before the implantation of a cardioverter defibrillator (ICD), if patients present with a cardiac arrest and no structural heart disease or a hypertrophic cardiomyopathy. In these patients the prevalence of a curable cause of the cardiac arrest, such as accessory pathways or an idiopathic ventricular tachycardia (VT), is high and the ICD implantation may be avoided. The same is true for patients who present with a cardiac arrest and a short PQ interval or a delta wave. If patients present with wide-complex tachycardias and the diagnosis of VT is unclear, an EPS and PVS are also clearly indicated. If patients have syncope or nonsustained VTs and a structural heart disease, PVS may be used for risk stratification. However, EPS and PVS may be of little use in patients with a structural heart disease and an impaired left ventricular function after a survived cardiac arrest or an unstable VT, which makes them candidates for ICD implantation anyway.

Death, Sudden, Cardiac↗

PubMed2005

[Idiopathic dilated cardiomyopathy--an appraisal in 2005].

Patients who present with an impaired left ventricular (LV) function of nonischemic origin (EF < or = 35%), should first undergo intensified heart failure therapy with angiotensin-converting enzyme (ACE) inhibitors, beta-blockers and diuretics. If the impairment of LV function persists for 3-9 months despite adequate therapy, the implantation of a defibrillator (ICD) seems to be reasonable for the primary prevention of sudden cardiac death in these patients. If patients present with non-sustained ventricular tachycardias, ICD implantation and treatment with amiodarone are probably equally effective and better than mere heart failure therapy. In patients presenting with an indication for biventricular pacing, a biventricular ICD should be used.

Cardiomyopathy, Dilated↗

PubMed2005

Complete pulmonary vein isolation guided by three-dimensional electroanatomical mapping for the treatment of paroxysmal atrial fibrillation in patients with hypertrophic obstructive cardiomyopathy.

AIMS: Evaluation of the clinical outcome of patients with hypertrophic obstructive cardiomyopathy (HOCM) and paroxysmal atrial fibrillation (AF) treated with complete pulmonary vein (PV) isolation guided by three-dimensional (3-D) electroanatomical (EA) mapping. METHODS: Circumferential radiofrequency (RF) ablation and continuous circular lesions (CCLs) around the left and right-sided PVs were performed in 4 highly symptomatic patients (2 males; age 57.5 +/- 8.3 years) with HOCM and anti-arrhythmic drug (AAD) refractory paroxysmal AF. Ablation was guided by 3-D EA mapping combined with conventional circumferential PV mapping. The endpoints of the ablation were defined as: (1) absence of all PV spikes documented with the two Lasso catheters within the ipsilateral PVs; and (2) no recurrence of the PV spikes within all PVs following intravenous administration of adenosine. RESULTS: The ablation endpoints were achieved in all patients. A repeat ablation was performed in one patient due to repetitive atrial tachycardia, 1 month after the initial procedure. During a follow-up of 5.8 +/- 2.7 months, all patients are free of AF recurrence. Short episodes of symptomatic AT were documented after the repeat procedure, and were well controlled with oral amiodarone in the patient. No procedure-related complications were observed. CONCLUSION: The present study demonstrates that complete isolation of ipsilateral PVs guided by 3-D EA mapping is potentially effective for the treatment of highly symptomatic, drug refractory paroxysmal AF in patients with HOCM.

Aged↗

PubMed2005

Topographic distribution of focal left atrial tachycardias defined by electrocardiographic and electrophysiological data.

BACKGROUND: Detailed information about the topographic distribution of focal left atrial tachycardias (FLATs) is limited. METHODS AND RESULTS: A total of 143 atrial tachycardia (AT) foci were successfully ablated in 140 patients (56 men, mean age 44.6+/-17.9 years). In 36.4% (52/143 ATs), a left atrial (LA) origin of the tachycardia was identified from the site of successful ablation. In 46% (24/52) of FLATs, the site of origin (SO) was near the ostium of a pulmonary vein (PV), and in 36.5% (19/52), the SO was near the mitral annulus (MA). In the remaining ATs, the SO was in the left atrial appendage (LAA), septum, LA roof and inside the coronary sinus. P waves in V1 showed biphasic morphology with an initial negative component in most FLATs originating from the septal MA, superior MA, and LAA. However, P waves in V1 were positive in all patients with FLATs originating from PVs. Negative P waves in aVL were always observed in FLATs originating from left PVs. The mean cycle length of FLATs from PVs was significantly shorter than that from the MA. CONCLUSION: Knowledge of the topographic distribution, P-wave morphology, and tachycardia cycle length facilitates successful ablation of FLATs.

Adult↗

PubMed2004

Recovered pulmonary vein conduction as a dominant factor for recurrent atrial tachyarrhythmias after complete circular isolation of the pulmonary veins: lessons from double Lasso technique.

BACKGROUND: Atrial tachyarrhythmias (ATa) can recur after continuous circular lesions (CCLs) around the ipsilateral pulmonary veins (PVs) in patients with atrial fibrillation (AF). This study characterizes the electrophysiological findings in patients with and without ATa after complete PV isolation. METHODS AND RESULTS: Twenty-nine of 100 patients had recurrent ATa after complete PV isolation by use of CCLs during a mean follow-up of approximately 8 months. A repeat procedure was performed in 26 patients with ATa and in 7 volunteers without ATa at 3 to 4 months after CCLs. No recovered PV conduction was demonstrated in the 7 volunteers, whereas recovered PV conduction was found in 21 patients with recurrent ATa (right-sided PVs in 9 patients and left-sided PVs in 16 patients). The interval from the onset of the P wave to the earliest PV spike was 157+/-66 ms in the right-sided PVs and 149+/-45 ms in the left-sided PVs. During the procedure, PV tachycardia activated the atrium and resulted in atrial tachycardia (AT) in 10 patients. All conduction gaps were successfully closed with segmental RF ablation. After PV isolation, macroreentrant AT was induced and ablated in 3 patients. In the 5 patients without PV conduction, focal AT in the left atrial roof in 2 patients and non-PV foci in the left atrium in 1 patient were successfully abolished; in the remaining 2 patients, no ablation was performed because of noninducible arrhythmias. During a mean follow-up of approximately 6 months, 24 patients were free of ATa without antiarrhythmic drugs. CONCLUSIONS: In patients with recurrent ATa after CCLs, recovered PV conduction is a dominant finding in approximately 80% of patients and can be successfully eliminated by segmental RF ablation. Also, mapping and ablation of non-PV arrhythmias can improve clinical success.

Aged↗

PubMed2004

Complete isolation of left atrium surrounding the pulmonary veins: new insights from the double-Lasso technique in paroxysmal atrial fibrillation.

BACKGROUND: Paroxysmal atrial fibrillation (PAF) can be eliminated with continuous circular lesions (CCLs) around the pulmonary veins (PVs), but it is unclear whether all PVs are completely isolated. METHODS AND RESULTS: Forty-one patients with symptomatic PAF underwent 3D mapping, and all PV ostia were marked on the 3D map based on venography. Irrigated radiofrequency energy was applied at a distance from the PV ostia guided by 2 Lasso catheters placed within the ipsilateral superior and inferior PVs. The mean radiofrequency duration was 1550+/-511 seconds for left-sided PVs and 1512+/-506 seconds for right-sided PVs. After isolation, automatic activity was observed in the right-sided PVs in 87.8% and in the left-sided PVs in 80.5%. During the procedure, a spontaneous or induced PV tachycardia (PVT) with a cycle length of 189+/-29 ms was observed in 19 patients. During a mean follow-up of 6 months, atrial tachyarrhythmias recurred in 10 patients. Nine patients underwent a repeat procedure. Conduction gaps in the left CCL in 9 patients and in the right CCL in 2 patients were closed during the second procedure. A spontaneous PVT with a cycle length of 212+/-44 ms was demonstrated in 7 of 9 patients, even though no PVT had been observed in 6 of these 7 patients during the first procedure. No AF recurred in 39 patients after PV isolation during follow-up. CONCLUSIONS: Automatic activity and fast tachycardia within the PVs could reflect an arrhythmogenic substrate in patients with PAF, which could be eliminated by isolating all PVs with CCLs guided by 3D mapping and the double-Lasso technique in the majority of patients.

Adenosine↗

PubMed2004

Initial experience with remote catheter ablation using a novel magnetic navigation system: magnetic remote catheter ablation.

BACKGROUND: Catheters are typically stiff and incorporate a pull-wire mechanism to allow tip deflection. While standing at the patient's side, the operator manually navigates the catheter in the heart using fluoroscopic guidance. METHODS AND RESULTS: A total of 42 patients (32 female; mean age, 55+/-15 years) underwent ablation of common-type (slow/fast) or uncommon-type (slow/slow) atrioventricular nodal reentrant tachycardia (AVNRT) with the use of the magnetic navigation system Niobe (Stereotaxis, Inc). It consists of 2 computer-controlled permanent magnets located on opposite sides of the patient, which create a steerable external magnetic field (0.08 T). A small magnet embedded in the catheter tip causes the catheter to align and to be steered by the external magnetic field. A motor drive advances or retracts the catheter, enabling complete remote navigation. Radiofrequency current was applied with the use of a remote-controlled 4-mm, solid-tip, magnetic navigation-enabled catheter (55 degrees C, maximum 40 W, 60 seconds) in all patients. The investigators, who were situated in the control room, performed the ablation using a mean of 7.2+/-4.7 radiofrequency current applications (mean fluoroscopy time, 8.9+/-6.2 minutes; procedure duration, 145+/-43 minutes). Slow pathway ablation was achieved in 15 patients, whereas slow pathway modulation was the end point in the remaining patients. There were no complications. CONCLUSIONS: The Niobe magnetic navigation system is a new platform technology allowing remote-controlled navigation of an ablation catheter. In conjunction with a motor drive unit, this system was used successfully to perform completely remote-controlled mapping and ablation in patients with AVNRT.

Adult↗

PubMed2004

Modulation of the slow pathway in the presence of a persistent left superior caval vein using the novel magnetic navigation system Niobe.

AIMS: This is the first report of a young female with typical AVNRT in the presence of a persistent left superior caval vein that underwent catheter ablation using the novel magnetic navigation system (MNS) Niobe (Stereotaxis Inc.). METHODS: The MNS consists of two outer permanent magnets (about 0.1 T) that align a third small magnet integrated in the tip of a mapping and ablation catheter along its magnetic field lines. By changing the orientation of the outer magnets, the orientation of the magnetic field lines also change, thereby allowing navigation of the ablation catheter. In combination with an automated advancer system, this novel technique allows for the first time complete remote catheter ablation. RESULTS: Successful slow pathway modulation was performed using a total of seven radiofrequency current applications via the magnetic ablation catheter. No complication occurred. CONCLUSIONS: The novel magnetic navigation system proved to be a safe and feasible tool for remote catheter ablation of common type AVNRT in the presence of a persistent left superior caval vein.

Adult↗