Efficacy and safety of catheter ablation for atrial fibrillation in congenital heart disease – A systematic review and meta-analysis

BackgroundPrevalence of atrial fibrillation (AF) in patients with congenital heart disease (CHD) is on the rise. Anti-arrhythmic drugs are usually the first line of treatment in CHD, however, it is often ineffective and poorly tolerated. We aimed to perform a systematic review to assess the efficacy and safety of catheter ablation for AF in CHD.MethodsWe performed a comprehensive search on catheter ablation for atrial fibrillation in congenital heart disease up until July 2019 through several electronic databases.ResultsAblation of AF in patients with CHD had a modest 12 months AF freedom ranging from 32.8% to 63%, which can be increased by subsequent/repeat ablation. The complexity of CHD appears to have a significant effect on a study but not in others. Catheter ablation in ASD and persistent left superior vena cava had a high success rate. Overall, catheter ablation is safe whichever the type of CHD is.ConclusionCatheter ablation for AF in CHD had modest efficacy that can be increased by subsequent/repeat ablation and it also has an excellent safety profile. Ablation in complex CHD could also have similar efficacy, however, it is preferably done by experts in a high volume tertiary center.     

First Dutch experience with the endoscopic laser balloon ablation system for the treatment of atrial fibrillation

IntroductionThe endoscopic laser balloon ablation system (EAS) is a relatively novel technique to perform pulmonary vein isolation (PVI) in the treatment of atrial fibrillation (AF). The present study aimed to report the results of the first 50 patients treated in the Netherlands with the EAS in terms of procedural characteristics and AF-free survival.MethodsFifty patients successfully underwent EAS PVI. Median follow-up was 17 months. Mean age was 56 years, 82 % had paroxysmal AF.Results99 % of the pulmonary veins were successfully isolated with the EAS. Mean procedure time was 171 min and mean fluoroscopy time was 36 min. One procedure was complicated by a temporary phrenic nerve palsy (2 %). During follow-up, 58 % of patients remained free of AF without the use of antiarrhythmic drugs.ConclusionPVI with EAS is associated with a low risk of complications and a medium-term AF-free survival comparable with other PVI techniques.

Electronic supplementary material

The online version of this article (doi:10.1007/s12471-014-0624-y) contains supplementary material, which is available to authorized users.     

Atrial fibrillation and preexcitation - A licence to kill

Atrial fibrillation becomes a potentially lethal arrhythmia in the presence of preexcitation because the rapid ventricular activation can result in ventricular fibrillation. Fortunately, radiofrequency ablation is an effective treatment for these patients. Specific points of interest regarding this association are the mechanism of increased incidence of atrial fibrillation and the current management of patients presenting in atrial fibrillation. These are discussed in this editorial.     

Selective induction of targeted cell death and elimination by near-infrared femtosecond laser ablation

The techniques for inducing the death of specific cells in tissue has attracted attention as new methodologies for studying cell function and tissue regeneration. In this study, we show that a sequential process of targeted cell death and removal can be triggered by short-term exposure of near-infrared femtosecond laser pulses. Kinetic analysis of the intracellular accumulation of trypan blue and the assay of caspase activity revealed that femtosecond laser pulses induced immediate disturbance of plasma membrane integrity followed by apoptosis-like cell death. Yet, adjacent cells showed no sign of membrane damage and no increased caspase activity. The laser-exposed cells eventually detached from the substrate after a delay of >54 min while adjacent cells remained intact. On the base of in vitro experiments, we applied the same approach to ablate targeted single cardiac cells of a live zebrafish heart. The ability of inducing targeted cell death with femtosecond laser pulses should find broad applications that benefit from precise cellular manipulation at the level of single cells in vivo and in vitro.     

Sequential Anterograde and Retrograde Conduction Block during Radiofrequency Ablation of an Accessory Pathway

We present an interesting image showing sequential loss of anterograde, and subsequently, retrograde conduction during radiofrequency ablation of an accessory pathway. We discuss the possible mechanisms and prior literature concerning this interesting finding.     

房室结折返性心动过速多径路食道电生理特征及意义 ———附1例报告暨文献复习

房室结多径路在临床中常见,其食道电生理有较典型特征,如多种频率心动过速。我们发现一例食道调搏存在两种频率心动过速患者,第一次在右延伸处成功慢径改良后较长时间不能发现另一条慢径存在,40分钟后另一条慢径才表现并于左延长处成功消融。提示如食道电生理发现存在多径路时心内电生理一定要多次重复检查,必要时延长观察时间,力争一次完整消融多条径路。     

Pulmonary vein reconnection following cryo-ablation: Mind the “Gap” in the carinae and the left atrial appendage ridge

Pulmonary vein (PV) isolation (PVI) remains cornerstone to ablation of atrial fibrillation (AF). For effective and durable PVI and thus fewer AF recurrences, lesion gaps in transmurality and contiguity responsible for PV reconnection (PVR) could only be addressed when one is cognizant of the potential location and sites where these lesion characteristics may be more prevalent and responsible for PVR. In the case of RF ablation, newer technologies incorporating contact force, time and power with automated monitoring of lesion formation, paying attention to difficult areas (carinae, left superior PV-LAA ridge, right inferior PV) and measuring inter-lesion distance may provide the tools to reduce PVR. On the other hand, the improved thermodynamic characteristics of the latest generation of cryoballloons and operator dexterity to achieve better PV occlusion, may be crucial determinants towards the direction of reduced PVR. Whether newer visualization tools, more vigilant testing during the index ablation procedure in these particular regions, prolonging or adding cryothermic applications, waiting longer to test for entrance and exit block, and/or use of provocative drug testing (isoproterenol/adenosine challenge) might help prevent future PVRs awaits further studies.     

QRS alternans during right ventricular pacing while ablating a concealed left sided accessory pathway

A 16-year-old boy was referred for an electrophysiological study for documented regular narrow complex tachycardia. A diagnosis of a concealed left lateral accessory pathway was made with an eccentric atrial activation sequence both during tachycardia and right ventricular (RV) pacing. The pathway was mapped at the left posterior mitral vestibule during RV pacing, performed through the distal tip of the His bundle catheter pushed into right ventricular outflow tract. An unusual response to ventricular stimulation with alternation of QRS complex width and morphology was noted. The possible mechanisms are hereby discussed.     

Trans-jugular vein approach for ablation of ventricular premature contractions originating from the tricuspid annulus

A young-male underwent radiofrequency (RF) ablation of ventricular premature contractions (VPCs) of over 30,000/day and the morphology exhibited left bundle branch block and a superior axis, which indicated the VPCs originated from the inferior portion of the right ventricle (RV). While the PENTARAY catheter was placed under the tricuspid valve (TV), the earliest potential, which preceded the QRS onset by 34 ms, was recorded. Pace mapping there presented a very similar QRS morphology to the target VPC. However, the radiofrequency (RF)-catheter could not be placed under the TV even when a deflectable sheath was used, because the deflectable curve of the RF-catheter was larger than that of the PENTARAY. An over-the-vale RF application was not effective, so the trans-jugular approach with a deflectable sheath was indicated. The tip of the sheath was placed at a higher portion of the RV cavity to maintain an adequate distance for the RF-catheter tip to be deflected and placed under the TV. With this maneuver, the tip of the RF-catheter was successfully placed under the TV, which was confirmed by intracardiac ultrasound. Small atrial potentials and larger ventricular potentials could be recorded from the distal tip of the RF-catheter, which might indicate that the tip was placed at the TV annulus. An RF application at that site permanently abolished the VPC. Placing the tip of the RF-catheter under the TV by the femoral approach is very difficult in some cases. The trans-jugular approach with a deflectable sheath is one option for arrhythmias from the TV.