Simple Pulmonary Vein Isolation Research Articles

Pulsed field ablation for all types of atrial fibrillation single centre experience with individualized approach and medium-term outcome

Abstract Funding Acknowledgements Type of funding sources: None. Background Pulsed field ablation (PFA) is a promising method to reduce procedure time and improve ablation safety and efficacy in all types of atrial fibrillation (AF). Purpose To present ablation approach and medium-term outcomes of PFA in all AF types. Methods Between 9/2021-10/2022, PFA using Farawave catheter was performed in 250 patients (63±11 years, 65 females). Patients with paroxysmal AF were basically scheduled for simple pulmonary vein isolation (PVI) (Farawave, ICE), patients with longstanding AF (LSPAF) underwent complex left atrial (LA) PFA (Farawave, CS 10-pole catheter, ICE); ablation extent varied in persistent AF. Results Paroxysmal AF (n=131; 115 ablated in SR), persistent AF (n=39; 11 ablated in SR), and LSPAF (n=64) were ablated with procedure times 58±20, 105±28, and 116±32 minutes, respectively, and fluoroscopy times 9±5, 14±7, and 17±7 minutes, respectively. Additional 16 patients underwent PFA for atrial tachycardia (AT). Ongoing AF was terminated by PFA in 13/16 (81%), 16/28 (57%), and 23/64 (36%) patients with paroxysmal AF, persistent AF, and LSPAF, respectively. In groups of paroxysmal AF ablated in SR, paroxysmal AF ablated in AF, persistent AF ablated in SR, persistent AF, and LSPAF, simple PVI was performed in 100%, 50%, 73%, 11%, and 0 patients respectively; and freedom from AF/AT was present in 86/99 (87%), 11/14 (79%), 7/10 (70%), 11/12 (92%), and 40/52 (77%) patients, respectively, of total 187 patients with follow-up ≥3 months (≥6 months in 139 patients). In 8 patients with repeat ablation post-PFA for paroxysmal AF (n=4), persistent AF (n=2), LSPAF (n=2), extra-PV AF/AT sources dominated in all groups. Complications included one tamponade with pericardiocentesis, and prolonged ST elevation with negative coronary angiography. Conclusion PFA using Farawave catheter was associated with reduced procedure times and favourable medium-term outcome for all AF types. Early experience specifically suggests improved outcome after extensive LA ablation for persistent AF/LSPAF.

Multielectrode Pulmonary Vein Isolation Versus Single Tip Wide Area Catheter Ablation for Paroxysmal Atrial Fibrillation: A Multinational Multicenter Randomized Clinical Trial.

Single-shot ablation techniques may facilitate safe and simple pulmonary vein isolation to treat paroxysmal atrial fibrillation. Multielectrode pulmonary vein isolation versus single tip wide area catheter ablation-paroxysmal atrial fibrillation is the first multinational, multicenter, prospective, noninferiority randomized clinical trial comparing multielectrode-phased radiofrequency ablation (MEA) to standard focal irrigated radiofrequency ablation (STA) using 3-dimensional navigation. Patients with paroxysmal atrial fibrillation were randomized to MEA (61 patients) or STA (59 patients). Preprocedure transesophageal echocardiogram and computed tomography/magnetic resonance imaging (also 6-month postprocedure) were performed. Mean age was 57 years, 25% female sex, BMI was 28, CHA2DS2-VASc score was 0 to 1 in 82%, 8% had previous right atrial ablation, whereas all had at least 1 antiarrhythmic drug failure. The MEA group had significantly shorter mean procedure time (96±36 versus 166±46 minutes, P<0.001) and fluoroscopy time (23±9 versus 27±9 minutes, P=0.023). The total radiofrequency energy duration was 22±8 minutes for MEA versus 36±13 minutes for STA (P<0.001) with confirmed pulmonary vein isolation in all patients. Hospital admission was 1 day in both groups, without major adverse events either during the procedure or during 30-day follow-up. Two patients in the STA group had 1 PV with asymptomatic narrowing >50%. Freedom of atrial fibrillation for MEA and STA was 86.4% and 89.7% at 6 months, dropping to 76.3% and 81.0% at 12 months. In this multicenter, randomized clinical trial, MEA and STA had similar rates of single-procedure acute pulmonary vein isolation without serious adverse events in the first 30 days. MEA had slightly lower long-term arrhythmia freedom, but showed marked and significantly shorter procedure, fluoroscopy, and radiofrequency energy times. URL: www.clinicaltrials.gov; Unique identifier: NCT01696136.

Maze permutations during minimally invasive mitral valve surgery.

Surgical ablation for atrial fibrillation is most frequently done in the concomitant setting, and most commonly with mitral valve surgery. Minimally invasive surgical techniques for the treatment of atrial fibrillation have developed contemporaneously with techniques for minimally invasive mitral valve surgery. As in traditional surgery for atrial fibrillation, there are many different permutations of ablations for the less invasive approaches. Lesion sets can vary from simple pulmonary vein isolation (PVI) to full bi-atrial lesions that completely reproduce the traditional cut-and-sew Cox Maze III procedure with variable efficacy in restoring sinus rhythm. Additionally, treatment of the atrial appendage can be done through minimally invasive approaches without any ablation at all in an attempt to mitigate the risk of stroke. Finally, hybrid procedures combining minimally invasive surgery and catheter-based ablation are being developed that might augment surgical treatment of atrial fibrillation at the time of minimally invasive mitral valve repair. These various permutations and their results are reviewed.

Pulmonary vein isolation for persistent atrial fibrillation. Long-term results.

Pulmonary vein isolation has been employed to eliminate paroxysmal atrial fibrillation. However, the long-term outcome in terms of long-standing persistent atrial fibrillation is unclear. One hundred patients with rheumatic mitral valve disease and long-standing (>1 year) persistent atrial fibrillation were operated on between July 1998 and June 2007. Mitral valve surgery and surgical isolation (cut-and-sew) of the pulmonary veins were performed in all cases. Transthoracic echocardiography and 24-h Holter monitoring were obtained after 3 and 6 months and yearly thereafter. Early and late follow-up was 99% and 92% complete, respectively. The endpoint was freedom from atrial fibrillation. There was one (1%) hospital death. Atrial fibrillation was present in 39%, 47%, 63% and 68% of patients at 3 months, 1 year, 3 years, and 5 years after surgery, respectively. The odds ratios for recurrence of atrial fibrillation postoperatively were 1.41 (95% confidence interval 1.14-1.74), 2.17 (95% confidence interval 1.63-2.90), and 3.62 (95% confidence interval 2.44-5.38) at 1 week, 3 years, and 5 years, respectively. Actuarial freedom from atrial fibrillation was 35% at 3 years, and 30% at 5 years. A direct relationship was observed between preoperative left atrial size >6 cm and atrial fibrillation recurrence at 5 years (p < 0.05 odds ratio = 2.5, 95% confidence interval 1.15 - 5.4). No beneficial effects of simple pulmonary vein isolation for long-standing persistent atrial fibrillation concomitant with rheumatic mitral valve disease were observed. Atrial fibrillation cannot be fully treated using only pulmonary vein isolation.

The developing pulmonary veins and left atrium: implications for ablation strategy for atrial fibrillation†

The majority of cases of atrial fibrillation (AF) are the result of triggers originating in the area of the pulmonary veins. The reason for the predilection for that area remains unclear. We sought to examine the different mechanisms responsible for this observation through an extensive search of the medical literature, examining the development of the pulmonary veins, genetics of AF and left to -right cardiac chamber differentiation. Results confirm that the LAA is anatomically and embryologically different from other areas of the atrial walls and develops under distinct genetic and transcriptional pathways. Findings support an ablation strategy whose primary focus should be the creation of a 'box' lesion set, plus additional lines to prevent propagation to the left atrial appendage, the isthmus of the left atrium and the right atrium are likely to be more effective than simple pulmonary vein isolation.

EComment. Surgery to treat atrial fibrillation: Which technique is the best?

I read with interest the article by Basu et al [1]. There is no doubt that bipolar radiofrequency (RF) ablation is better than unipolar RF ablation to cure the atrial fibrillation (AF) because of the full transmurality achieved almost exclusively by the bipolar RF. I have discussed this matter previously [2,3]. The presumed basis of successful AF ablation is production of myocardial lesions that block the propagation of AF wave fronts from a rapidly firing triggering source or modification of the arrhythmogenic substrate responsible for re-entry. Successful ablation depends upon achieving lesions that are reliably transmural. The hypothetical scenario with the patient described by Basu et al. [1] corresponds to a Class IIa indication with supporting evidence graded as level C for concomitant surgical ablation of AF, according to the Expert Consensus Statement on Catheter and Surgical Ablation of Atrial Fibrillation [4]. Whether simple pulmonary vein (PV) isolation or a more complete Cox-maze IV procedure with irrigated bipolar RF ablation is performed may perhaps be the most important point of discussion in this paper. On the one hand, it is well known that paroxysmal AF triggers occurs into the pulmonary veins up to 90% of the cases. In other words, simple PV isolation has a limited success in eliminating AF . On the other hand, the Cox-maze III procedure, when properly performed in a standard “cut-and-sew” fashion, cures AF in nearly 100% of the patients with or without concomitant disease [5]. However, the long aortic clamp times have always been the hallmark of this procedure. Simplification of the maze procedure has evolved toward newer streamlined surgical approaches using different ablation tools. Irrigated bipolar RF ablation seems to be the more effective to reach to goal. Nevertheless, the success rate of curing AF remains limited. In fact, until now there is no paper in the literature demonstrating an effectiveness of 100% with the electric Cox-maze IV procedure. Finally, we should keep in mind that in the real world the Cox-maze III “cut-and-sew” standard procedure is reserved only to a select number of cardiac surgeons because of its high surgical complexity. In conclusion, I think that bipolar RF ablation is better than unipolar RF ablation in treating AF. Procedures that are more complete than simple PV isolation such as the electric Cox-maze IV with bipolar RF ablation must be performed. If the case is treated within an experienced and referral centre, the Cox- maze III “cut-and-sew” is the standard procedure of choice to eliminate AF. Conflict of Interest: None declared

4/5D Integrated Mapping for Atrial Fibrillation Ablation

The majority of AF ablative cases are guided by 2D fluoroscopy with an additional dimensionality added by circular lasso-type catheters. While this may be sufficient for simple pulmonary vein isolation, recurrence rates in paroxysmal patients remain as high as 20–30%. Many patients have extensive underlying disease and more chronic atrial fibrillation not amenable to simple pulmonary vein isolation. Four/five dimensional imaging provides the venue for the chronicling of physiology (such as CAFE and ganglion plexus activity) within the context of 3 spatial dimensions. In addition, real-time registration may be of even greater importance in guiding the ablation of more complicated atrial fibrillation types. This may be even more important, as more sophisticated energy sources are developed, including those to be delivered from outside of the body. Studies have already demonstrated an improvement in procedure times with a mapped approach, while others demonstrate a reduction in fluoroscopic exposure. The use of 4/5D imaging is also critically important to realize the full potential of robotics, which can be programmed to deal with complicated structures. The same is true in the full integration of contact force sensing for ablative intervention. This report will chronicle experience to date with 3/4D mapping systems, as well as the progression in their application for contact sensing, complex electrogram-based ablation, robotic interventions, and for guiding extracorporeal energy deliveries.

Midterm Results of Pulmonary Vein Isolation for the Elimination of Chronic Atrial Fibrillation

This study aims to clarify midterm results of chronic atrial fibrillation elimination after pulmonary vein isolation and provides an evaluation of factors influencing results. Forty-nine patients were enrolled in this study. We performed a simple pulmonary vein isolation with the aid of cryoablation or radiofrequency ablation directed towards the left posterior remnant of the posterior left atrium. Results were evaluated using elimination rates of atrial fibrillation during the postoperative follow-up for > 12 months. We also examined factors influencing the recurrence of atrial fibrillation. There were no hospital deaths or serious complications among the 49 patients. The total follow-up duration was 137.2 patient years. Forty-seven patients (96%) were followed with serial consultations, but 2 patients were dropped from this study because of changes in residence. Thirty-five of 49 patients (71.4%) showed regular sinus or nodal rhythms at discharge. In 4 patients atrial fibrillation recurred during the follow-up period, whereas in another 4 patients sinus rhythm was restored, although they showed atrial fibrillation at discharge. The cumulative elimination rate was 70.2% (33 of 47 patients), which was determined at the last follow-up period. Large left atrial diameters, a long history of atrial fibrillation, and low-voltage fibrillatory waves in V1 leads were preoperative indicators of recurrence of atrial fibrillation. Pulmonary vein isolations were effective in the treatment of chronic atrial fibrillation patients and sinus rhythms were restored within the follow-up period.

Simple surgical isolation of pulmonary veins for treating secondary atrial fibrillation in mitral valve disease

Background. hronic atrial fibrillation (AF) due to mitral valve disease has been successfully treated by surgery. We performed a study to evaluate the effectiveness of a surgical method of simple pulmonary vein isolation (PVI) without radiofrequency or cryoablation in the restoration of sinus rhythm in a group of patients.Methods. Fifteen patients were operated on for mitral valve disease and chronic AF. The technique consists basically of a circumferential incision excluding the pulmonary vein ostia from the left atrium.Results. Sinus rhythm was achieved in 92.3% of the patients at 6-month follow-up. Echocardiograms 2 months after surgery showed a mean decrease of 1.1 cm in left atrial size. Effective atrial ejection was reestablished in all patients in whom sinus rhythm was achieved (mean LA ejection fraction 41% ± 14%). Twenty-four hour Holter recordings did not show episodes of paroxysmal atrial fibrillation in any patients. Four patients had isolated episodes of ventricular ectopic beats. Stress electrocardiograms showed mean maximal ventricular response was 64% ± 11% and 73% ± 9% of predicted value at 2 and 6 months, respectively. All patients had improved NYHA functional class after surgery; 74% of patients were in NYHA functional class I at 6 months compared with 13.3% preoperatively.Conclusions. Pulmonary vein isolation without the use of radiofrequency or cryoablation is effective in restoring sinus rhythm in patients with chronic AF secondary to mitral valve disease. Based on simple surgical incisions, this technique is more advantageous than others requiring additional instrumentation.