Lara Dabiri Abkenari

The entirely subcutaneous implantable cardioverter-defibrillator: initial clinical experience in a large Dutch cohort.

OBJECTIVES The purpose of the study was to evaluate the efficacy and safety of the entirely subcutaneous implantable cardioverter-defibrillator (S-ICD). BACKGROUND A new entirely S-ICD has been introduced, that does not require lead placement in or on the heart. The authors report the largest multicenter experience to date with the S-ICD with a minimum of 1-year follow-up in the first 118 Dutch patients who were implanted with this device. METHODS Patients were selected if they had a class I or IIa indication for primary or secondary prevention of sudden cardiac death. All consecutive patients from 4 high-volume centers in the Netherlands with an S-ICD implanted between December 2008 and April 2011 were included. RESULTS A total of 118 patients (75% males, mean age 50 years) received the S-ICD. After 18 months of follow-up, 8 patients experienced 45 successful appropriate shocks (98% first shock conversion efficacy). No sudden deaths occurred. Fifteen patients (13%) received inappropriate shocks, mainly due to T-wave oversensing, which was mostly solved by a software upgrade and changing the sensing vector of the S-ICD. Sixteen patients (14%) experienced complications. Adverse events were more frequent in the first 15 implantations per center compared with subsequent implantations (inappropriate shocks 19% vs. 6.7%, p = 0.03; complications 17% vs. 10%, p = 0.10). CONCLUSIONS This study demonstrates that the S-ICD is effective in terminating ventricular arrhythmias. There is, however, a considerable percentage of ICD related adverse events, which decreases as the therapy evolves and experience increases.

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.

Evaluation of the need of elective implantable cardioverter-defibrillator generator replacement in primary prevention patients without prior appropriate ICD therapy

Objective It is not clear whether patients who received an implantable cardioverter-defibrillator (ICD) for primary prevention should undergo device replacement if they never experienced an appropriate ICD therapy during the first generator longevity. This study evaluated the incidence and predictors of appropriate ICD therapy after device replacement in this specific population. Methods From two large prospective ICD registries, we identified all primary prevention patients who had a first ICD replacement without previous appropriate ICD therapy. Cox regression analysis was used to identify predictors of appropriate ICD therapy. Results Of 403 primary prevention patients needing first ICD replacement, 275 patients (68%) had not received previous appropriate ICD therapy. Patients without previous appropriate ICD therapy before first ICD replacement (mean age at replacement 62±12 years, 75% male) had a mean follow-up of 86±24 months after the initial implantation and 30±24 months after device replacement. Following replacement, 3-year cumulative incidence of appropriate ICD therapy was 13.7% (95% CI 8.6 to 18.8%). No predictive factors associated with appropriate ICD therapy after replacement could be identified in spite of including seven clinically relevant factors. Conclusions A considerable number of primary prevention patients without previous appropriate ICD therapy before first ICD replacement received appropriate ICD therapy after replacement. As there were no predictors of appropriate ICD therapy after replacement, replacing an ICD is still recommended in all primary prevention patients despite the lack of appropriate ICD therapy during first battery service life.

Safety and Clinical Outcome of Catheter Ablation of Ventricular Arrhythmias Using Contact Force Sensing: Consecutive Case Series.

Poor catheter‐to‐myocardial contact can lead to ineffective ablation lesions and suboptimal outcome. Contact force (CF) sensing catheters in ventricular tachyarrhythmia (VT) ablations have not been studied for their long‐term efficacy.

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.

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.

So you implanted an implantable cardioverter defibrillator, now what to do with it?

This editorial refers to ‘Long-term follow-up on high-rate cut-off programming for implantable cardioverter defibrillators in primary prevention patients with left ventricular systolic dysfunction’ by N. Clementy et al ., on page 968 It is well established that patients with a low ejection fraction, be it ischaemic cardiomyopathy or not, benefit from implantable cardioverter defibrillator (ICD) therapy.1,2 Since the hallmark studies, this has been shown repeatedly in real-world studies and in a meta-analysis.3,4 However, this therapy comes with implant-related complications and the psychological strain of shocks, both appropriate and inappropriate.5 Recently, the relation between shocks and mortality has been investigated. The initial question of who to implant with an ICD is closely followed by many others. Single-chamber or dual-chamber pacing (and sensing)? How many zones to programme? Which cut-off rate (and duration to intervention) should be used? What is the benefit or disadvantage of anti-tachycardia pacing (ATP), and how should this be programmed? Finally, which detection intervals and parameters are optimal to treat all important arrhythmias, while avoiding unnecessary and inappropriate shocks. Most of these questions have never been studied systematically. Ventricular pacing can have detrimental effects in patients with left ventricular dysfunction and should be avoided. It is clear now that pacing should be atrial, or at 40 b.p.m. in the ventricle.6 The effects of zone programming have never been studied as such. In MADIT (Multicenter Automatic Defibrillator Implantation Trial) II, programming was left to physician discretion, and both single- and double-chamber devices were used.1 In SCD-HeFT (Sudden Cardiac Death in Heart Failure Trial) only single-chamber devices …