Ferdi Akca

The magnetic navigation system allows safety and high efficacy for ablation of arrhythmias

Aims We aimed to evaluate the safety and long-term efficacy of the magnetic navigation system (MNS) in a large number of patients. The MNS has the potential for improving safety and efficacy based on atraumatic catheter design and superior navigation capabilities. Methods and results In this study, 610 consecutive patients underwent ablation. Patients were divided into two age- and sex-matched groups. Ablations were performed either using MNS (group MNS, 292) or conventional manual ablation [group manual navigation (MAN), 318]. The following parameters were analysed: acute success rate, fluoroscopy time, procedure time, complications [major: pericardial tamponade, permanent atrioventricular (AV) block, major bleeding, and death; minor: minor bleeding and temporary AV block]. Recurrence rate was assessed during follow-up (15 ± 9.5 months). Subgroup analysis was performed for the following groups: atrial fibrillation, isthmus dependent and atypical atrial flutter, atrial tachycardia, AV nodal re-entrant tachycardia, circus movement tachycardia, and ventricular tachycardia (VT). Magnetic navigation system was associated with less major complications (0.34 vs. 3.2%, P = 0.01). The total numbers of complications were lower in group MNS (4.5 vs. 10%, P = 0.005). Magnetic navigation system was equally effective as MAN in acute success rate for overall groups (92 vs. 94%, P = ns). Magnetic navigation system was more successful for VTs (93 vs. 72%, P < 0.05). Less fluoroscopy was used in group MNS (30 ± 20 vs. 35 ± 25 min, P < 0.01). There were no differences in procedure times and recurrence rates for the overall groups (168 ± 67 vs. 159 ± 75 min, P = ns; 14 vs. 11%, P = ns; respectively). Conclusions Our data suggest that the use of MNS improves safety without compromising efficiency of ablations. Magnetic navigation system is more effective than manual ablation for VTs.

Acute and Long-Term Outcomes of Catheter Ablation Using Remote Magnetic Navigation in Patients With Congenital Heart Disease

The aim of the present study was to assess the feasibility, safety, and long-term results of remote magnetic navigation in arrhythmias associated with complex congenital heart disease (CHD). The improved outcomes for CHD resulted in an increased number of complex arrhythmias requiring distinctive ablation techniques. Thirty-six patients with CHD (age 35 ± 19 years, 21 male) were divided into 3 complexity groups and underwent 43 radiofrequency catheter ablation procedures using the magnetic navigation system (including 7 redo ablations) in combination with the CARTO RMT system. A total of 59 tachyarrhythmias were identified. Most patients had surgical scar-related tachycardia (25 focal, including 4 microreentrant atrial tachycardia, and 27 macroreentrant atrial tachycardia). Four accessory pathways and three ventricular tachycardias were diagnosed and treated. In 31 patients, ablation was successful, with an end point of noninducibility (86%). The success rate for CHD complexity of type I, II, and III was 50%, 88%, and 89%, respectively. The mean procedure and fluoroscopy time was 216 ± 101 minutes and 40 ± 34 minutes, respectively. The number of radiofrequency applications was 42 ± 47. No major complications related to the procedures occurred. Of the patients, 67% remained free of recurrence during a mean follow-up of 26 ± 4 months. Recurrence developed in 0%, 16%, and 45% of patients with CHD type I, II, and III, respectively. In conclusion, the magnetic navigation system is feasible to treat arrhythmias with reasonable success rates and good long-term outcomes in adult patients with CHD. The use of the magnetic navigation system offers advantages in complex anatomic situations.

Catheter Ablation of Ventricular Tachycardias Using Remote Magnetic Navigation: A Consecutive Case–Control Study

Remote Magnetic Navigation for VT Ablation. Background: This study aimed to compare acute and late outcomes of VT ablation using the magnetic navigation system (MNS) to manual techniques (MAN) in patients with (SHD) and without (NSHD) structural heart disease.

The prevalence of early repolarization in patients with noncompaction cardiomyopathy presenting with malignant ventricular arrhythmias

Early Repolarization in Noncompaction Cardiomyopathy. Background: Early repolarization (ER) is associated with malignant ventricular arrhythmias, including ventricular fibrillation (VF) and sudden cardiac death (SCD). One possible mechanism is increased trabeculation with deep intramyocardial invagination, carrying the Purkinje system deeper into the myocardium resulting in delayed depolarization and inhomogenous repolarization. Noncompaction cardiomyopathy (NCCM) is a recently classified, primary cardiomyopathy with excessive trabeculations. In these patients ventricular arrhythmias, including sustained VT and VF, occur frequently. The aim of this study was to determine the prevalence of ER in NCCM patients, especially in those primarily presenting with malignant ventricular arrhythmias or SCD.

A prospective study on safety of catheter ablation procedures: Contact force guided ablation could reduce the risk of cardiac perforation

BACKGROUND Contact force (CF) sensing catheters provide advantages with regard to safety and efficacy. This study aimed to evaluate if CF catheters reduce cardiac perforations and other major complications and offer equal safety compared to the magnetic navigation system (MNS). METHODS Data from 1.517 ablation procedures from our prospective registry was analyzed. Ablations were performed using either CF guided catheters (CF group, n=248), non-CF catheters (NCF group, n=813), or MNS (n=456). Four subgroups were analyzed: atrial fibrillation (AF, n=557), supraventricular tachycardia (SVT, n=715), ventricular tachycardia (VT, n=190) and patients with congenital heart defects (CHD, n=55). The primary endpoint of this study was incidence of cardiac perforation. Secondary endpoints were major and minor complications within 30 days of the procedure. RESULTS Complications occurred in 11.3% (n=172) of the procedures. In 2.8% (n=43) a major complication occurred, 0.9% (n=13) had a perforation, 8.5% (n=129) had a minor complication and 2 patients died (0.1%). No cardiac perforation occurred in the CF group, which was significantly different from NCF procedures (0.0% vs. 1.6%; relative risk 0.76, 95% CI 0.74-0.79, P=0.031) and equal to MNS (0.0%). This was also observed in the AF subgroup (0.0% vs. 3.3%; RR 0.67, 95% CI 0.63-0.72, P=0.021), and the occurrence of major complications was lower for CF versus NCF procedures (2.1% vs. 7.8%, P=0.010). CONCLUSIONS CF-guided catheter ablation is superior to NCF with regard to procedural safety and avoidance of cardiac perforation. This difference is due to a reduction of cardiac perforation and major complications in the AF subgroup.

Safety and efficacy of the remote magnetic navigation for ablation of ventricular tachycardias--a systematic review.

ObjectiveRemote magnetic navigation (RMN) is considered to be a solution for mapping and ablation of several arrhythmias. In this systematic review we aimed to assess the safety and efficacy of RMN in ablation of ventricular tachycardia (VT).MethodsThe National Library of Medicine’s PubMed database was searched for articles containing any of a predetermined set of search terms that were published prior to November 1, 2011. Quality of evidence was rated using the GRADE system.ResultsThe database search resulted in 11 relevant articles evaluating the usefulness of RMN. Three groups of VTs were studied: VT in patients with ischemic cardiomyopathy (ICMP), non-ischemic cardiomyopathy (NICMP) and structurally normal hearts (SNH). The use of RMN in patients with ICMP has been associated with success rates ranging from 71 to 80%. RMN has been shown to be a feasible and effective method for ablation of VT in NICMP and SNH patients. Success rates between 50% and 100% have been reported in NICMP populations. Rates ranging from 86% to 100% have been reported for SNH patients. The lowest rates of arrhythmia recurrence are reported for SNH patients (0–17%). In ICMP and NICMP, recurrence rates of 0–30% and 14–50%, respectively, have been reported. One patient experienced total heart block, and one patient experienced a thromboembolic event after RMN catheter ablation procedures.ConclusionsRMN has been shown to be an effective and safe method for ablation of VT in various patient populations with low recurrence and complication rates. However, more comparative and randomized studies are necessary, and therefore the true value of RMN for VT ablation remains still unknown.

Empiric slow pathway ablation in non-inducible supraventricular tachycardia

BACKGROUND The data supporting the practice of empiric slow pathway ablation (ESPA) in patients with documented supraventricular tachycardia (SVT) who are non-inducible at electrophysiology study (EPS) is limited. The aim of this study is to assess the efficacy of ESPA in adults. METHODS A multi-center cohort study of patients who had ESPA between January 2008 and October 2013 was performed. Patients were identified by screening sequential SVT ablation procedures. RESULTS Forty-three (5%) out of 859 SVT ablation procedures were identified as ESPA. The median age was 53 (IQR: 24) years; 63% were female. All patients had pre-EPS documentation of SVT (either strip or ECG). In 23 (53.5%) cases, pre-EPS ECG showed short RP tachycardia. Thirty-two (74.4%) patients had dual atrioventricular nodal physiology (DAVNP) plus echo beats. Junctional rhythm (JR) as procedural endpoint was noted in 39 (90.7%) patients. In 18 (41.9%) patients, the abolishment of DAVNP was achieved. No complications were encountered. A median follow-up of 17 months (range: 6 to 31 months) revealed 83.7% (36 of 43) success rate, defined as the absence of pre-procedural symptoms and any documented sustained arrhythmia. As compared to patients with recurrence (n=7), patients with no recurrence (n=36) had significantly higher prevalence of clinical short RP tachycardia (61.1% vs. 14.3%, p=0.038), and EPS finding of DAVNP plus echo beats (80.6% vs. 42.9%, p=0.034). CONCLUSIONS ESPA is a reasonable approach in patients with documented SVT, in particular in short RP tachycardia, who are not inducible at EPS. Larger studies are required to assess this practice.

Outcomes of repeat catheter ablation using magnetic navigation or conventional ablation

AIMS After initial catheter ablation, repeat procedures could be necessary. This study evaluates the efficacy of the magnetic navigation system (MNS) in repeat catheter ablation as compared with manual conventional techniques (MANs). METHODS AND RESULTS The results of 163 repeat ablation procedures were analysed. Ablations were performed either using MNS (n = 84) or conventional manual ablation (n = 79). Procedures were divided into four groups based on the technique used during the initial and repeat ablation procedure: MAN-MAN (n = 66), MAN-MNS (n = 31), MNS-MNS (n = 53), and MNS-MAN (n = 13). Three subgroups were analysed: supraventricular tachycardias (SVTs, n = 68), atrial fibrillation (AF, n = 67), and ventricular tachycardias (VT, n = 28). Recurrences were assessed during 19 ± 11 months follow-up. Overall, repeat procedures using MNS were successful in 89.0% as compared with 96.2% in the MAN group (P = ns). The overall recurrence rate was significantly lower using MNS (25.0 vs. 41.4%, P = 0.045). Acute success and recurrence rates for the MAN-MAN, MAN-MNS, MNS-MNS, and MNS-MAN groups were comparable. For the SVT subgroup a higher acute success rate was achieved using MAN (87.9 vs. 100.0%, P = 0.049). The use of MNS for SVT is associated with longer procedure times (205 ± 82 vs. 172 ± 69 min, P = 0.040). For AF procedure and fluoroscopy times were longer (257 ± 72 vs. 185 ± 64, P = 0.001; 59.5 ± 19.3 vs. 41.1 ± 18.3 min, P < 0.001). Less fluoroscopy was used for MNS-guided VT procedures (22.8 ± 14.7 vs. 41.2 ± 10.9, P = 0.011). CONCLUSION Our data suggest that overall MNS is comparable with MAN in acute success after repeat catheter ablation. However, MNS is related to fewer recurrences as compared with MAN.

The presence of extensive atrial scars hinders the differential diagnosis of focal or macroreentrant atrial tachycardias in patients with complex congenital heart disease

AIMS Atrial tachycardias (ATs) frequently develop in patients with congenital heart defects (CHDs). This study aimed to evaluate the effects of extensive atrial scar formation on the total atrial activation time (TAAT) and its relation to the tachycardia cycle length (CL) to classify AT. METHODS AND RESULTS Seventy-one patients were included and divided into two groups: patients without CHD (Group I, 35 patients) and with CHD (Group II, 36 patients). All patients underwent CARTO electroanatomical activation mapping. Two subgroups were created: centrifugal (CAT) or macroreentrant AT (MRAT). Total atrial activation time, CL, and mean bipolar signal amplitude (BiSA) were analysed. In Group I, 18 patients (51.4%) had CAT and 17 (48.6%) MRAT. The mean BiSA for Group I was 1.30 ± 0.32 mV. Total atrial activation time/CL ratios were different between CAT and MRAT (28.4 ± 16.9 vs. 66.6 ± 14.3%, P < 0.001). In Group II, 18 patients (50%) had CAT and 18 patients (50%) MRAT. The mean BiSA was 0.94 ± 0.50 mV and was not different for CAT and MRAT subgroups (1.04 ± 0.64 vs. 0.85 ± 0.29, P = 0.243). Total atrial activation time/CL ratios were comparable between CAT and MRAT patients (69.0 ± 40.4 vs. 83.6 ± 8.3%, P = 0.243). A significant lower BiSA was found for CAT with TAAT/CL ratios above 40% (0.62 ± 0.11 vs. 1.90 ± 0.18 mV, P < 0.001). A strong negative correlation was identified between the BiSA and the TAAT/CL ratio in patients with CAT in Group II (-0.742; P < 0.001). CONCLUSION Low mean BiSA values in CHD patients are associated with altered impulse propagation, making TAAT- and CL-based diagnostic tools inaccurate. Further diagnostic tests are needed to determine the correct mechanism of ATs.

High-volume lesions using a new second-generation open irrigation radiofrequency catheter are associated with the development of inhomogeneous lesions

After catheter ablation there is often a discrepancy between acute and chronic success rates. We aimed to evaluate major determinants for lesion quality and understand different manifestations of lesion structures.