Linear ablation of left atrium for the treatment of atrial fibrillation guided by double Lasso catheters and three dimensional electroanatomical mapping

Background Linear ablation of left atrium （LA） guided by three dimensional （3-D） electroanatomical mapping （Carto） has been used in many centres worldwide for the treatment of atrial fibrillation （AF） instead of pure anatomical approaches. There were little data about linear ablation of LA guided by Carto and double Lasso catheters in China. We report the results of linear ablation of LA guided by both Carto and double Lasso catheters. Methods After the anatomical model of LA and all pulmonary veins （PVs） had been established, circumferential ablations of the left pulmonary vein antrum and the right pulmonary vein antrum were performed with 2 circumferential mapping catheters （Lasso） placed within the ipsilateral superior and inferior PVs. The endpoint of ablation was abolishment or dissociation of the pulmonary vein potentials （PVPs）. Oral amiodarone or propafenone was taken for at least 3 months by patients with persistent AF, permanent AF or those whose PVPs had not been isolated completely. The recurrence of atrial tachyarrhythmias was observed 3 months after the procedure. Results There were 106 patients （mean age, 51.4±9.9 years）. Seventy-eight patients had paroxysmal AF, 12 persistent AF and 16 permanent AF. Onset of atrial fibrillation occurred in 52 patients during ablation procedure. Thirty-two patients restored to sinus rhythm eventually after the procedure. Abolishment or dissociation of PVPs was accomplished during the procedure in 94 patients （88.7%）. The duration of procedure and exposure to X-ray were （213±45） minutes and （32.5± 12.8） minutes, respectively. Among the 87 patients followed up for over 3 months, 62 were free of atrial tachyarrhythmias （including 8 patients who were still taking oral amiodarone）. The success rate was 71.3% in the first procedure. Two patients had pericardial effusion treated by pericardial puncture and effusion drainage. No pulmonary vein stenosis, atrioesophageal fistula, stroke or procedural death occurred. Conclusions Combination of double Lasso catheters with 3-D electroanatomical mapping to guide the linear ablation of left atrium procedure can confirm the isolation of PVPs.

Manifold benefits of choosing a minimally fluoroscopic catheter ablation approach

We report the case of a 14-year-old boy with ventricular preexcitation. A standard, fluoroscopy guided, ablation procedure was successfully performed in a postero-midseptal region with a total fluoroscopy time of about 45 min (2430 cGy.cm2). A few hours after the procedure, preexcitation reappeared. A second ablation procedure was scheduled using the EnSite NavXTM mapping system. During mapping along the tricuspid groove, preexcitation suddenly disappeared due to mechanical "bumping" of the accessory pathway and it did not recover over the next 30 min. As per our routine practice, the phase of geometry reconstruction has been continuously recorded by the system; thus, an off-line analysis allowed to pinpoint the site of earliest activation and the site of mechanical bumping, where radiofrequency obtained the accessory pathway ablation. The second procedure was performed without using fluoroscopy at all. Thanks to the geometry reconstruction, the procedure was completely successful thus avoiding a further rehospitalization.

Role of three-dimensional imaging integration in atrial fibrillation ablation

Atrial fibrillation is the most common arrhythmia and in symptomatic patients with a drug-refractory form,catheter ablation aimed at electrically disconnecting the pulmonary veins(PVs) has proved more effective than use of antiarrhythmic drugs in maintaining sinus rhythm during follow-up.On the other hand,this ablation procedure is complex,requires specific training and adequate clinical experience.A main challenge is represented by the need for accurate sequential positioning of the ablation catheter around each veno-atrial junction to deliver point-by-point radiofrequency energy applications in order to achieve complete and persistent electrical disconnection of the PVs.Imaging integration is a new technology that enables guidance during this procedure by showing a three-dimensional,pre-acquired computed tomography or magnetic resonance image and the relative real-time position of the ablation catheter on the screen of the electroanatomic system.Reports in the literature suggest that imaging integration provides accurate visual information with improvement in the procedure parameters and/or clinical outcomes of the procedure.

Role of catheter ablation of ventricular tachycardia associated with structural heart disease

In patients with structural heart disease, ventricular tachycardia (VT) worsens the clinical condition and may severely affect the shortand long-term prognosis. Several therapeutic options can be considered for the management of this arrhythmia. Among others, catheter ablation, a closed-chest therapy, can prevent arrhythmia recurrences by abolishing the arrhythmogenic substrate. Over the last two decades, different techniques have been developed for an effective approach to both tolerated and untolerated VTs. The clinical outcome of patients undergoing ablation has been evaluated in multiple studies. This editorial gives an overview of the role, methodology, clinical outcome and innovative approaches in catheter ablation of VT.

Changing the Way We“See”Scar:How Multimodality Imaging Fits in the Electrophysiology Laboratory

Substrate characterization is the mainstay of ablation for ventricular tachycardia(VT).Although the use of electroanatomic voltage mapping(EAVM)in the electrophysiology(EP)laboratory has enabled real-time approximation of myocardial scar,it has limitations.This is related to the subjective and tedious nature of voltage mapping and the challenges of defi ning the transmurality of scar.Various noninvasive methods of scar assessment have emerged,with magnetic resonance imaging(MRI)being the most accurate.Integrated MRI and electroanatomic voltage mapping studies demonstrate good correlation.Nonetheless,MRI has advantages.These include(1)preprocedure identifi cation of epicardial and intramural scar,(2)assessment of ablative lesion formation after unsuccessful ablations,(3)identifi-cation of heterogeneous regions of scar,where critical conducting channels are likely to occur,and(4)predictive value in the assessment of sudden cardiac death(SCD).Integration of scar imaging in ventricular tachycardia ablation and risk stratifi cation has great potential to advance the practice of arrhythmia management.

Left atrial voltage remodeling after pulmonary venous isolation with multipolar radiofrequency ablation

Purpose: Pulmonary vein isolation (PVI) is the accepted primary endpoint for catheter ablation of atrial fibrillation (AF). The aim of this study was to evaluate the level of PVI by PVAC, a multipolar circular catheter utilizing bipolar/unipolar radiofrequency (RF) energy. Methods: Twenty patients with paroxysmal AF underwent PVAC ablation. PVI was validated by voltage reduction and pacing tests. Before and after RF ablation, left atrium (LA) and PV electroanatomic mapping (EAM) were performed by EnSite NavX system. Voltage abatement was considered for potentials 24mm: 9/20 (45%) vs 11/57 (19%),

A randomized prospective comparison of CartoMerge and CartoXP to guide circumferential pulmonary vein isolation for the treatment of paroxysmal atrial fibrillation

Background CartoXP and CartoMerge have been used to treat atrial fibrillation （AF） for several years. Our randomized prospective study compared clinical outcomes of these two versions of three dimensional electroanatomic mapping system in guiding catheter ablation for paroxysmal atrial fibrillation （PAF）. Methods Eighty-one patients with symptomatic, drug refractory PAF were randomly assigned to CartoMerge group （n=-42, mean age （54.5 ＋ 13.1） years, history of AF = 3.2 years） or CartoXP group （n=39, mean age （59.8 ± 15.6） years, history of AF = 2.9 years）. All patients underwent 64-slice computed tomography （MSCT） 1 to 3 days prior to ablation procedure. Using CartoMergeTM Image Integration Module, 3D anatomical images of the left atrium （LA） and pulmonary veins （PVS） derived from MSCT of CartoMerge group were established and merged with the electroanatomical map. The integrated images were used to guide the procedure of circumferential pulmonary vein isolation （CPVl）. In the other group, CPVl was guided just by CartoXP. The endpoint of CPVl in both groups was abolition or dissociation of pulmonary vein potentials （PVPs）. Results Mapping points to establish the electroanatomical model of the LA/PVs were 48.7＋13.4 in CartoMerge group and 62.5±15.7 in CartoXP group （P〈0.001）. Mean distance between mapping points and the MSCT surfaces in CartoMerge group was （1.59±0.33） mm. Accomplishment of abolition or dissociation of PVPs was achieved 95.2% in CartoMerge group and 92.3% in CartoXP group. Durations of procedure and exposure to X-ray were （156±25） minutes, （179±21） minutes （P〈0.001） and （19.6±7.5） minutes, （28.5±12.8） minutes （P 〈0.001）, respectively. After a follow-up with duration of （11.9＋3.1） months vs （12.4±3.6） months post the first ablation procedure, patients free of AF were 33 （78.6%） in CartoMerge group and 29 （74.4%） in CartoXP group （P〉0.50）. No patient suffered pulmonary vein stenosis, atenoesophageal fistula, stroke or death. Conclusion Compared to CartoXP, CartoMerge shortened the catheter ablation procedure and exposure to X-ray, without affecting the clinical outcomes of circumferential pulmonary vein isolation for the treatment of paroxysmal atrial fibrillation in experienced centres.

Initial experience with circumferential pulmonary vein ablation guided by fusion of magnetic resonance imaging with three-dimensional electroanatomic mapping

Catheter ablation for the treatment of atrial fibrillation （AF） has been a focal target ofelectrophysiological study in recent years. Up to date, circumferential pulmonary vein ablation （CPVA） guided by three-dimensional （3-D） electreanatomic mapping （Carto, USA） has been one of the most favourable procedures for the treatment of AF. However, it is still difficult to acquire the detailed information on number, location, and branching pattern of all pulmonary veins （PVs） when the 3-D electroanatomic mapping system is used alone.

Initial experience with circumferential pulmonary vein isolation guided~ by Overlay Ref and CartoMerge in the treatment of paroxysmal atrial fibrillation

Background CartoMerge has been widely used in guiding circumferential pulmonary vein isolation （CPVI） for the treatment of paroxysmal atrial fibrillation （PAF）. However, the procedure of landmarks selection varies among operators according to their experience. Techniques have to be established to standardize this procedure. We propose that Overlay Ref could facilitate this procedure. This paper aimed to report our initial experience with CPVI guided by Overlay Ref and CartoMerge for the treatment of PAF. Methods Fifty-nine patients with PAF were enrolled in this study. Using Overlay Ref technique, a reference image （inverted） was faded into the live fluoroscopic image. Landmarks of CartoMerge were selected from anatomic points of the top of superior pulmonary veins （PVs） and the bottom of inferior PVs guided by Overlay Ref image. Overlay Ref images were also used to guide the ablation procedure combining with CartoMerge. Results All patients were successfully mapped by CartoMerge guided by Overlay Ref. The distance between the mapping points and the CT surfaces was （1.42±0.67） mm for the patients as a whole. This led to a successful rate of 96% for isolation of pulmonary veins. Duration of ablation procedure was （92±17） minutes. And the total duration of procedure was （139±32） minutes. CartoMerge could also be performed just with 3 paries to 4 paries selected landmarks guided by Overlay Ref without a full anatomic model constructed by Carto. Then, the total duration of procedure could be shortened to （115±38） minutes. Conclusions Overlay Ref technique can facilitate the catheter ablation of PAF and can help to standardize the procedure of landmarks selection.