Project description:Background:Balloon-based ablation systems for pulmonary vein isolation (PVI) are providing procedural safety and efficacy as well as favourable clinical outcome. Although second-generation laser balloon (LB2) based PVI has been shown safety and efficacy relatively long procedural duration was a strong limitation. The third-generation laser balloon (LB3) offers and automized ablation for rapid PVI. We determined safety, efficacy and procedural characteristics of this new promising ablation system. Methods and results:A total of 15 consecutive patients were prospectively enrolled. All patients underwent PVI using the LB3. A total 59/59 PVs (100%) were successfully isolated. Procedural data was compared to the last 15 consecutive patients treated by the LB2. The median procedure time significantly declined from LB2 (91 (86, 105) min) to LB3 (77 (68, 87) min), p < 0.001. Similarly, the median left atrial dwelling time significantly decreased from LB2 (72 (62, 84) min) to LB3 (45 (38, 52) min), p < 0.0001. The total laser time decreased from LB2 (1920 (1765, 2193) sec) to LB3 (1077 (896, 1165) sec), p < 0.00001. A pure single shot PVI was performed in 18/59 PVs (31%). For major adverse events no differences were detected between the groups (LB2 1/15 (6.7%) and LB3 1/15 (6.7%), p = 0.999). Conclusion:The LB3 was safe and effective for PVI. Procedure time, LA dwelling time and total laser time significantly decreased compared to LB2.
Project description:IntroductionRadiofrequency (RF) atrial fibrillation (AF) ablation using a catheter dragging technique may shorten procedural duration and improve durability of pulmonary vein isolation (PVI) by creating uninterrupted linear ablation lesions. We compared a novel AF ablation approach guided by Grid annotation allowing for "drag lesions" with a standard point-by-point ablation approach in a single-center randomized study.MethodsEighty-eight paroxysmal or persistent AF patients were randomized 1:1 to undergo RF-PVI with either a catheter dragging ablation technique guided by Grid annotation or point-by-point ablation guided by Ablation Index (AI) annotation. In the Grid annotation arm, ablation was visualized using 1 mm³ grid points coloring red after meeting predefined stability and contact force criteria. In the AI annotation arm, ablation lesions were created in a point-by-point fashion with AI target values set at 380 and 500 for posterior/inferior and anterior/roof segments, respectively. Patients were followed up for 12 months after PVI using ECGs, 24-h Holter monitoring and a mobile-based one-lead ECG device.ResultsProcedure time was not different between the two randomization arms (Grid annotation 71 ± 19 min, AI annotation 72 ± 26 min, p = .765). RF time was significantly longer in the Grid annotation arm compared with the AI annotation arm (49 ± 8 min vs. 37 ± 8 min, respectively, p < .001). Atrial tachyarrhythmia recurrence was documented in 10 patients (23%) in the Grid annotation arm compared with 19 patients (42%) in the AI annotation arm with time to recurrence not reaching statistical significance (p = .074).ConclusionsThis study shows that a Grid annotation-guided dragging approach provides an alternative to point-by-point RF-PVI using AI annotation.
Project description:AimsPulmonary vein isolation is effective in reducing atrial fibrillation (AF) episodes. Previous studies suggest single-shot techniques are effective and safe for this purpose. Procedural and clinical outcomes were compared between multi-electrode and point-by-point radiofrequency ablations by performing a meta-analysis of all randomized and non-randomized studies.Methods and resultsSystematic reviews of MEDLINE and Cochrane Library databases were performed. Studies comparing procedural (procedure and fluoroscopy times) and clinical (AF recurrence) outcomes were included in the meta-analysis. A total of 13 clinical studies (5 randomized and 8 non-randomized) including 2152 patients met the inclusion criteria. In patients underwent multi-electrode ablation, there were significant reductions in both total procedure and fluoroscopy times, compared with point-by-point ablation (mean difference = -34.3 min [95% CI (-50.1 to -18.5)], p < 0.001 and mean difference = -7.1 min [95% CI (-12.0 to -2.2)], p < 0.01, respectively). These significances also continued in patients with paroxysmal AF. No such difference was observed in regard to AF recurrence between the 2 ablation strategies (RR = 0.90 [95% CI (0.80-1.01)], p = 0.066). This insignificance was also observed in patients with paroxysmal AF.ConclusionsIn a heterogeneous AF population, multi-electrode ablation is as effective as point-by-point ablation, with better procedural and fluoroscopy durations.
Project description:Background?:Tetralogy of Fallot is a congenital heart defect characterized by pulmonary valve stenosis, ventricular septal defect (VSD), overriding aorta, and right ventricular hypertrophy. In its' extreme form, the pulmonary valve orifice does not develop during organogenesis, resulting in pulmonary atresia. We report a case of catheter ablation of symptomatic atrial fibrillation (AF) in a 37-year-old patient with congenital pulmonary atresia. Case summary?:The young man described paroxysmal tachycardia correlating to AF episodes in the previously implanted event recorder. Computed tomography scan described the complex anatomy with congenital pulmonary atresia, VSD, and major aortopulmonary collateral arteries. Electroanatomical mapping revealed typical pulmonary vein electrograms in a hypotrophic left atrium. Modified pulmonary vein isolation was successfully performed and non-excitability of the ablation line was reached. The patient recovered uneventfully and event recorder interrogation showed no AF recurrence after 3 months. Discussion?:Incidence of pulmonary atresia is low. Untreated survival rate is 50% after 1 year and 8% after 10?years. Tachycardia is a major cause of increased morbidity and mortality in patients with cyanotic congenital heart defects and pulmonary vein foci are described as driver for AF. Considerations preceding catheter ablation included pathophysiological mechanism, complex anatomy, atypical left atrium access, and reduced pulmonary perfusion resulting in a hypotrophic left atrium. Pulmonary veins showed typical electrograms, and isolation of pulmonary veins was feasible without adverse events.
Project description:Atrial fibrillation (AF), the most prevalent cardiac arrhythmia, is commonly initiated by ectopic beats originating from a small myocardial sleeve extending over the pulmonary veins. Pulmonary vein isolation therapy attempts to isolate the pulmonary veins from the left atrium by ablating tissue, commonly by using radiofrequency ablation. During this procedure, the cardiologist records electrical activity using a lasso catheter, and the activation pattern recorded is used as a guide toward which regions to ablate. However, poor contact between electrode and tissue can lead to important regions of electrical activity not being recorded in clinic. We reproduce these signals through the use of a phenomenological model of the cardiac action potential on a cylinder, which we fit to post-AF atrial cells, and model the bipolar electrodes of the lasso catheter by an approximation of the surface potential. The resulting activation pattern is validated by direct comparison with those of clinical recordings. A potential application of the model is to reconstruct the missing electrical activity, minimizing the impact of the information loss on the clinical procedure, and we present results to demonstrate this.
Project description:The efficacy and safety of catheter ablation for the management of atrial fibrillation (AF) has been improved in recent years. Radiofrequency (RF) catheter ablation for maintaining sinus rhythm is superior to the current antiarrhythmic drug therapy in selected patients. Pulmonary vein isolation (PVI) is the cornerstone of various catheter ablation strategies. It is well recognized that pulmonary vein (PV) antrum contributes to the AF initiation and/or perpetuation. Since PV stenosis is a complication of ablation within a PV, the ablation site for PVI has shifted to the junction between the left atrium and the PV rather than the ostium of the PV. However, PV reconnection after ablation is the major cause of recurrence of AF. The recovery of PV conduction could be caused by anatomical variations such as the failure to produce complete transmural lesion or gaps at the ablation line due to the transient electrophysiologic effects from the RF ablation. In this review, we discussed several factors to be considered for the achievement of the best PVI, including clinical aspects and technical aspects.
Project description:PurposeReal-time observation of pulmonary vein (PV) potentials with a spiral mapping catheter has emerged as a key electrogram-based procedural parameter to estimate lesion quality and titrate cryoenergy application during PV isolation (PVI) with the cryoballoon. Whether correct PV electrogram interpretation and thus PVI real-time observation rate depends on atrial rhythm during cryoballoon PVI is unknown. We compared observation rates of time-to PV isolation (TTI) during sinus rhythm (SR group) and during atrial fibrillation (AFib group) in cryoballoon PVI.MethodsWe prospectively included 157 consecutive patients undergoing cryoballoon PVI and compared the incidence of PVI real-time recording of each pulmonary vein during SR and in AFib.ResultsOverall PVI real-time observation rate was 82.1% (491/598 PV) with significantly higher TTI observation rate in the SR group (315/365 PV, 86.3%) compared to the AFib group (176/233 PV, 75.5%; p < 0.001). Per vein analysis demonstrated that only TTI observation rate in the left superior pulmonary vein (LSPV) was significantly higher during SR (85/92, 92.4%) compared to AFib (37/54, 68.5%; p < 0.001). Regression analysis revealed that atrial rhythm is a strong and independent predictor of PVI real-time observation in the LSPV with an odds ratio of 4.98 (95%-CI: 1.86-13.34, p = 0.001) to detect TTI during SR.ConclusionsOur results demonstrate that correct interpretation of PV electrograms and thus PVI real-time observation is more likely in SR than in AFib. Hence, cardioversion of patients in AFib at the beginning of the procedure should be considered to yield higher PVI real-time observation rates facilitating TTI guided cryoenergy titration.
Project description:IntroductionThe optimal ablation approach for persistent atrial fibrillation (AF) remains unclear.Methods and resultsObjective was to compare the long-term rates of freedom from AF/AT in patients that underwent STAR mapping guided ablation against outcomes of patients undergoing conventional ablation procedures. Patients undergoing ablation for persistent AF as part of the Stochastic Trajectory Analysis of Ranked signals (STAR) mapping study were included. Outcomes following 'pulmonary vein isolation (PVI) plus STAR mapping guided ablation (STAR mapping cohort) were compared to patients undergoing PVI alone ablation during the same time period and also a propensity-matched cohort undergoing PVI plus the addition of complex fractionated electrogram (CFAE) and/or linear ablation ("conventional ablation"). Rates of procedural AF termination and freedom from AF/AT during follow-up were compared. Sixty-five patients were included in both the STAR cohort and propensity matched conventional ablation cohort. AF termination rates were significantly higher in the STAR cohort (51/65, 78.5%) than conventional ablation cohort (10/65, 15.4%) and PVI alone ablation cohort (13/50, 26.0%; STAR cohort vs. other 2 cohorts both p < .001). There was no significant difference in procedure time between the three cohorts. During ≥20 months follow-up a lower proportion of patients had AF/AT recurrence in the STAR cohort (20.0%) compared with the conventional ablation cohort (50.8%) or the PVI alone ablation cohort (50.0%; both p < .05 compared to STAR cohort).ConclusionsOutcomes of PVI plus STAR mapping guided ablation was superior to PVI alone or in combination with linear/CFAE ablation. A multicenter randomized controlled trial is planned to confirm these findings.
Project description:To improve the single-procedural success and long-term outcomes of catheter ablation techniques for AF, there is a need for durable, contiguous and transmural lesions encircling the pulmonary veins (PV). Measurement of contact force (CF) between the catheter tip and the target tissue can optimise ablation procedures. A new approach to obtain single-procedure durable PV isolation (PVI) using the latest CF technology combined with the CARTO VISITAG™ Module with Ablation Index (Biosense Webster) has been shown in small studies to almost eliminate recurrence of paroxysmal AF at 1-year follow up and to make PVI procedures more reproducible. The use of a standardised workflow is expected to increase the reproducibility of results and to increase the efficiency of PVI procedures.
Project description:The muscular discontinuities at the pulmonary vein (PV)-left atrial (LA) junction are known. The high-density mapping may help to find the muscular discontinuity. This study evaluated the efficacy of a partial antral ablation for a pulmonary vein (PV) isolation using high density (HD) mapping. A total of 60 drug-refractory atrial fibrillation (AF) patients undergoing catheter ablation were enrolled. The detailed activation mapping of each PV and LA junction was performed using an HD mapping system, and each PV segment's activation pattern was classified into a "directly-activated from the LA" or "passively-activated from an adjacent PV segment" pattern. The antral ablations were performed at the directly-activated PV segments only when the PV had "passively-activated segments". If the PV did not contain passively-activated segments, a circumferential antral ablation was performed on those PVs. A "successful partial antral ablation" was designated if the electrical isolation of targeted PV was achieved by ablation at the directly-activated segments only. If the isolation was not achieved even though all directly-activated segments were ablated, a "failed partial antral ablation" was designated, and then a circumferential ablation was performed. Among 240 PVs, passively-activated segments were observed in 140 (58.3%) PVs. Both inferior PVs had more passively-activated segments than superior PVs, and the posteroinferior segments had the highest proportion of passive activation. The overall rate of successful partial antral ablation was 85%. The atrial tachyarrhythmia recurrence was observed in 10 patients (16.7%) at 1-year. HD mapping allowed the evaluation of the detailed activation patterns of the PVs, and passively-activated segments may represent muscular discontinuity. Partial antral ablation of directly-activated antral segments only was feasible and effective for a PVI.