Circumferential Pulmonary Vein Isolation Research Articles

Role of sST2 in predicting recurrence of atrial fibrillation after radiofrequency catheter ablation.

Atrial fibrosis is associated with atrial fibrillation (AF) recurrence after ablation. This study aims to determine the relationship between soluble ST2 (sST2), a profibrotic biomarker, and AF recurrence after radiofrequency catheter ablation (RFCA). AF patients referred for RFCA were consecutively included from October 2017 to May 2019. Baseline characteristics were collected, and sST2 levels were determined before ablation. Left atrial substrate mapping was performed after circumferential pulmonary vein isolation under sinus rhythm, and substrate was modified in low-voltage zones. A second procedure was recommended under recurrence. Two hundred fifty-eight patients (146 males, average age 61.0 ± 8.8) were included. After a medium follow-up of 13.5 months, 52 patients (20.2%) had recurrence and received a second procedure. Preoperative sST2 level in patients with recurrence was significantly higher than that in patients without (31.3ng/mL vs 20.3ng/mL, P<.001). In those undergoing second ablation, sST2 level in patients with new abnormalities during endocardial mapping was significantly higher than that in patients without (43.0ng/mL vs 22.1ng/mL, P<.001). An sST2 level over 26.9ng/mL could predict AF recurrence with new abnormalities during endocardial mapping with a sensitivity of 100% and a specificity of 75.9%. Multiple logistic analysis showed that sST2 level was an independent predictor of AF recurrence with new abnormalities during endocardial mapping (P<.001). sST2 level was associated with new abnormalities during endocardial mapping and recurrence of AF after ablation. It might have significance in choosing treatment strategies for AF.

Initial experience with fractionation mapping-guided ablation strategy in patients with long-standing persistent atrial fibrillation.

We aimed to define the role of extended pulmonary vein isolation (PVI), posterior wall isolation, and mitral isthmus lines to eliminate electrograms exhibiting fractionation pattern during stepwise ablation on acute atrial fibrillation (AF) termination rate in patients with long-standing persistent AF (LSPAF). Twelve patients with LSPAF underwent ablation during AF. Using the fractionation mapping tool of the Ensite™ (Abbott Medical, Chicago, USA) system, sites exhibiting discrete atrial complexes and consistent activation sequence were mapped. The areas with a fractionation score above 4 were accepted as potential drivers for AF. During stepwise ablation consisting of circumferential PVI, roof and floor lines for posterior wall isolation, and mitral isthmus lines, ablation lines were extended toward potential AF drivers on the fractionation map as much as possible until sinus was achieved by ablation. Fractionation-guided ablation caused acute AF termination in 8 of 12 patients. In 6 of 12 cases, AF returned to sinus rhythm during the extended ablation. In 2 patients, AF shifted to sinus after cavotricuspid isthmus ablation. Sinus was achieved by cardioversion in 3 of cases. Procedural failure was seen in one case with significant scar tissue. During a mean follow-up of 31.5 ± 11months, overall arrhythmia-free survival was 92% with 2 procedures. This pilot study demonstrates that fractionation mapping-guided ablation may provide an adjunctive benefit in terms of acute AF termination in patients with LSPAF. These results should be confirmed by larger, randomized, comparison studies between linear ablation and extended ablation without elimination of electrograms (EGMs) with fractionation.

Association of Atrial Fibrillation Episode Duration With Arrhythmia Recurrence Following Ablation

Contemporary guidelines recommend that atrial fibrillation (AF) be classified based on episode duration, with these categories forming the basis of therapeutic recommendations. While pragmatic, these classifications are not based on pathophysiologic processes and may not reflect clinical outcomes. To evaluate the association of baseline AF episode duration with post-AF ablation arrhythmia outcomes. The current study is a secondary analysis of a prospective, parallel-group, multicenter, single-masked randomized clinical trial (the Cryoballoon vs Irrigated Radiofrequency Catheter Ablation: Double Short vs Standard Exposure Duration [CIRCA-DOSE] study), which took place at 8 Canadian centers. Between September 2014 and July 2017, 346 patients older than 18 years with symptomatic AF referred for first catheter ablation were enrolled. All patients received an implantable cardiac monitor at least 30 days before ablation. Data analysis was performed in September 2019. Before ablation, patients were classified based on their longest AF episode. Ablation consisted of circumferential pulmonary vein isolation using standard techniques. Time to first recurrence of symptomatic or asymptomatic atrial tachyarrhythmia (AF, atrial flutter, or atrial tachycardia) following ablation and AF burden (percentage of time in AF) on preablation and postablation continuous rhythm monitoring. The study included 346 patients (mean [SD] age, 59 [10] years; 231 [67.7%] men). Overall, 263 patients (76.0%) had AF episode duration of less than 24 hours; 25 (7.2%), 24 to 48 hours; 40 (11.7%), 2 to 7 days; and 18 (5.2%), more than 7 days. Documented recurrence of any atrial tachyarrhythmia following ablation was significantly lower in patients with baseline AF episode duration of less than 24 continuous hours compared with those with longer AF episodes (24 hours vs 24-48 hours: hazard ratio [HR], 0.41; 95% CI, 0.21-0.80; P = .009; 24 hours vs 2-7 days: HR, 0.25; 95% CI, 0.14-0.45; P < .001; 24 hours vs >7 days: HR, 0.23; 95% CI, 0.09-0.55; P < .001). Patients with preablation AF episodes limited to less than 24 continuous hours had a significantly lower median (interquartile range) postablation AF burden (0% [0%-0.1%]) compared with those with AF preablation episodes lasting 2-7 days (0.1% [0%-1.0%]; P = .003) and those with AF preablation episodes lasting more than 7 days (1.0% [0%-5.4%]; P = .008). There was no significant difference in arrhythmia recurrence or AF burden between the 3 groups with a baseline AF episode duration of longer than 24 hours. In this study, patients with AF episodes limited to less than 24 continuous hours had a significantly lower incidence of arrhythmia recurrence following AF ablation. This suggests that current guidelines for classification of AF may not reflect clinical outcomes. ClinicalTrials.gov Identifier: NCT01913522.

Electrophysiological significance of the interatrial conduction including cavo-tricuspid isthmus during atrial fibrillation.

The interatrial conduction, including Bachmann's bundle, the posterior septal conduction, the anterior septal conduction, and the cavo-tricuspid isthmus, contributes to the maintenance mechanisms of atrial fibrillation in a 3D biatrial model. The interatrial conduction ablation including a cavo-tricuspid isthmus ablation significantly affects the wave dynamics of atrial fibrillation (AF) and facilitates the AF termination or atrial tachycardia conversion of the AF after the circumferential pulmonary vein isolation. Additional cavo-tricuspid isthmus ablation after the circumferential pulmonary vein isolation improves long-term rhythm outcome after clinical AF catheter ablation. Although it is known that atrial fibrillation (AF) is mainly a left atrial (LA) disease, the role of the right atrium (RA) and interatrial conduction (IAC), including the cavo-tricuspid isthmus (CTI), has not been clearly defined. We tested AF wave dynamics with or without IAC in computational modelling and the rhythm outcome of AF catheter ablation (AFCA) including CTI ablation in clinical cohort data. We evaluated the dominant frequency (DF) in 3D biatrial AF simulations integrated with 3D-computed tomograms obtained from 10 patients. The IAC was implemented at Bachmann's bundle, posterior septum and the CTI. After virtual circumferential PV isolation (CPVI), we disconnected IACs one by one, and observed the wave dynamics. We compared the long-term rhythm outcome after CPVI alone and additional CTI ablation in 846 patients with AFCA. LA-DF was higher than RA-DF in AF (P<0.001). After CPVI, the DF decreased significantly by additional IAC ablation (P=0.003), especially in the LA (P=0.016). The amount of DF reduction (P=0.020) and rates of AF termination (P<0.001) or AT conversion (P=0.021) were significantly higher after IAC ablations including CTI than those without. In clinical AFCA, the AF recurrence rate was significantly lower in patients with additional CTI ablation than CPVI alone during 25±20months' follow-up (hazard ratio 0.60 [0.46-0.79], P<0.001, Log rank P<0.001). IAC contributes to the maintenance mechanism of AF, and IAC including CTI ablation affects AF wave dynamics, facilitating AF termination in 3D biatrial modelling. Additional CTI ablation after CPVI improves the long-term rhythm outcome in clinical AFCA, potentially in a paroxysmal type with accompanying atrial flutter, or atrial dimension close to normal.

Identification of circumferential pulmonary vein isolation responders among patients with persistent atrial fibrillation: clinical value of the sequential low-dose ibutilide test.

Circumferential pulmonary vein isolation can be effective as sole treatment for persistent atrial fibrillation. However, identifying those patients who will respond to this therapy remains a challenge. We investigated the clinical value of the sequential low-dose ibutilide test for identifying patients with persistent atrial fibrillation in whom pulmonary vein isolation is effective as sole therapy. In a prospective cohort of 180 consecutive patients with persistent atrial fibrillation, intravenous low-dose (0.004 mg/kg) ibutilide was administered 3 days before ablation and after the completion of circumferential pulmonary vein isolation. In patients in whom ibutilide did not terminate atrial fibrillation pre-procedurally, but successfully terminated it intraprocedurally, no further atrial substrate modification was performed. Pre-procedural low-dose ibutilide failed to terminate the arrhythmia in all patients with persistent atrial fibrillation, while pulmonary vein isolation ± low-dose ibutilide terminated persistent atrial fibrillation in 55 (30.6%) of them (PsAF group 1). The remaining 125 (69.4%) patients underwent electrogram-based ablation (PsAF Group 2). The control group comprised 379 consecutive patients with paroxysmal atrial fibrillation who underwent pulmonary vein isolation over the same period. At 24 months follow-up, 39 (70.9%) patients in PsAF Group 1 and 276 (72.8%) patients in the control group were free from atrial tachyarrhythmias (P = NS); the arrhythmia-free rates in both groups were higher than that in PsAF group 2 (58.4%, P = 0.005). The sequential low-dose ibutilide test is a simple method for identifying patients with persistent atrial fibrillation in whom pulmonary vein isolation alone is an appropriate treatment strategy.

Results of a survey concerning atrial fibrillation ablation strategies in Poland.

Catheter ablation is an effective treatment for patients with atrial fibrillation (AF). Despite the increasing availability of the procedure, current treatment patterns of invasive AF treatment in Poland are unknown. The aim of the study was to assess data on the contemporary approaches to AF ablation in Poland, such as: target population, patients' characteristics, ablation techniques, procedural results, and complication rates. The survey including 36 questions was conducted among 38 representatives of Polish electrophysiology centers performing AF catheter ablation to test the methods and outcomes in their laboratories. The survey was conducted among 38 out of 69 Polish electrophysiology centers performing AF ablation. There were 88 ablation laboratories in 2018 in Poland. They have performed 16 566 ablations, of which 6680 were AF ablations, according to the Polish National Health Fund data. Therefore, 3745 AF ablations analyzed in this study constituted 22.6% of all ablations and 56% of AF ablations performed in Poland in 2018.Paroxysmal AF was the most common type of AF in all surveyed centers. In 69% of the centers, the preferred method was cryoballoon ablation and in 31%, radiofrequency point‑by‑point circumferential pulmonary vein isolation. The reported complication rate was low (6.4%), with localadverse events being the most frequent. The mean reported incidence of atrial flutter or tachycardia after ablation was low (5%). Repeated procedures were performed mainly with radiofrequency ablation (89%). Procedural techniques and the type of venous access did not vary between the centers. Paroxysmal AF was the most common indication for percutaneous ablation of that arrhythmia in Polish electrophysiology laboratories. The preferred method was cryoballoon ablation.

P1021Low incidence of atrial tachycardia following ablation of low voltage areas in sinus rhythm for persistent atrial fibrillation

Abstract . Background: Dedicated ablation strategies for persistent atrial fibrillation (AF) have shown a limited success rate with frequent atrial tachycardia (AT) occurrence. Recent studies suggest that atrial arrhythmogenic sites are related to tissular heterogeneities and increased fibrosis can be identified as reduced bipolar voltage areas. . Purpose: Targeting low voltage areas (LVA) in addition to PVI may represent an efficient strategy for the ablation of persistent AF, and may limit the risk of AT recurrence. . Methods: We prospectively included consecutive patients with symptomatic persistent AF. The ablation strategy consisted of the following steps: circumferential pulmonary vein isolation (CPVI), Sinus rhythm restoration by electrical cardioversion, voltage map performed in sinus rhythm. Complementary RFA was guided by low voltage areas (0.2-0.4 mV). Success was defined as freedom from AF/ atrial flutter or atrial arrhythmia at 12 months or more. . Results: 101 patients (mean age: 62.5 +/- 10.4 years, men 73%) were included with persistent AF or long standing AF (7%). Procedure time was: 154 ± 25 min and fluoroscopy time: 184 ± 90 sec. Time of RFA was 44.7 +/- 12 min. Mean LA volume was 182 +/- 38 mL. LVA were found in 50 patients (49.5%). The distribution of these areas was: 30 anterior wall 29.7%), 21 septum (20.7%), 19 roof (18.8%), 5 inferior (4.9%), 11 left appendage (10.8%), 6 posterior (5.9%), 3 mitral isthmus (3%). RF ablation was realized for all LVA and homogenisation was attempt. After a single procedure at a mean FU of 12 months, 72.3% of patients were free of symptomatic AF. 27 patients had recurrence of atrial AF: 7 permanent, 15 persistent and 5 paroxysmal AF. Predictive factors of recurrence of AF were: long standing persistent AF, large left atrial volume (&amp;gt; 205 mL), shorts AF cycle length (&amp;lt; 168 ms) and reduce LEVF (&amp;lt; 45%). Atrial tachycardia occurred in 5 patients (4,9%). Mechanisms of AT were: typical cavo-tricuspid flutter in one patient, peri-mitral flutter in 2 patients, and atrial focal tachycardia (close to pulmonary veins) in 2 patients. . Conclusion: These results suggest that PVI with complementary RF ablation guided on low voltage areas is an efficient strategy for symptomatic persistent AF, and reduce the recurrence of AT following this ablation strategy.

P1415Wide antral circumferential pulmonary vein isolation ablation using a novel balloon cryoablation catheter

Abstract Background Pulmonary vein isolation using cryotherapy is an established treatment for the management of patients with paroxysmal atrial fibrillation. Ablation using the commercially available balloon cryocatheter has been shown to create wide antral pulmonary vein isolation. A novel balloon cryocatheter (BCC) has been designed to maintain uniform pressure and size during ablation, potentially improving contact with the antral anatomy. The extent of ablation created using the novel BCC has not previously been established. Purpose To determine the anatomical extent of pulmonary vein isolation using electroanatomical mapping when performing catheter ablation for paroxysmal atrial fibrillation using the novel BCC. Methods Nine consecutive patients underwent pre-procedure computed tomography angiography of the left atrium to quantify the chamber dimensions. An electroanatomical map was created using the cryoablation system mapping catheter and a high definition mapping system. A bipolar voltage map was obtained following ablation to determine the extent of pulmonary vein isolation ablation. A volumetric technique was used to quantify the extent of vein and posterior wall electrical isolation in addition to traditional techniques for proving entrance and exit block. Results All patients had paroxysmal atrial fibrillation, mean age 56 years, 7 (78%) male. Electrical isolation was achieved for 100% of the pulmonary veins; mean total procedure time was 109 min (+/- 26 SD), and fluoroscopy time 14.9 min (+/- 2.4 SD). The median treatment applications per vein was one (range one - four), and median treatment duration 180 sec (range 180 -240). Left atrial volume 32 mL/m2 (+/- 7 SD), and mean left atrial posterior wall area 22 cm2 (+/- 4 SD). Data was available for quantitative assessment of the extent of ablation for eight patients. No lesions (0 of 32) were ostial in nature. The antral surface area of ablation was not statistically different between the left and right sided pulmonary veins (p 0.63), which were 5.9 (1.6 SD) and 5.4 (2.1 SD) cm2 respectively. In total 50% of the posterior left atrial wall was ablated. Conclusion Pulmonary vein isolation using a novel BCC provides a wide and antral lesion set. There is significant debulking of the posterior wall of the left atrium. Abstract Figure.

P1382Extended long-term follow-up of radiofrequency catheter ablation for redo procedures after pulmonary vein isolation with the cryoballoon technique (first versus second generation cryoballoon)

Abstract Catheter ablation has become the first line of therapy in patients with symptomatic, recurrent, drug-refractory atrial fibrillation. Cryoablation has been shown to be a safe and effective technique for pulmonary vein isolation. However, there is a significant arrhythmia recurrence rate after cryoablation procedures and there are no established strategies for redo procedures in these patients. Therefore, we have summarized our experience with radiofrequency catheter ablation for redo procedures after pulmonary vein isolation with the cryoballoon technique (including an analysis of pulmonary vein conduction recovery patterns ater procedures performed with the first or second generation cryoballoon). Methods One hundred and twenty patients (paroxysmal AF: 78 patients, persistent AF: 42 patients) had to undergo a redo procedure after initially successful circumferential PV isolation with the cryoballoon technique. The redo ablation procedures were performed using a segmental approach or a circumferential ablation strategy depending on the intra-procedural findings. Results During the redo procedure, a mean number of 1.8 re-conducting PVs were detected (using a circular mapping catheter; group A: 2.1 re-conducting PVs, group B: 1.5 re-conducting PVs). There was a slightly higher incidence of chronic PV reconnections related to the left-sided PV ostia than to the right-sided PVs in both groups. Furthermore, sites of chronic PV reconnection were found more frequently in the inferior parts of the PV ostia than in the superior parts. In 53 patients in group A, a segmental approach was sufficient to eliminate the residual PV conduction because there were only a few recovered PV fibers (1-3 reconnected PVs; group A1). In the remaining 7 patients in group A, a circumferential ablation strategy was used because of a complete recovery of the PV-LA conduction of all four pulmonary veins (group A2). In group B, a segmental approach was sufficient in all patients because there was only a minor reconnection of 1-2 PVs. All recovered PVs could be isolated sucessfully again. At 42-month follow-up, 78 % of all patients were free from an arrhythmia recurrence (94/120 patients; group A: 43/60 patients (71 %), group B: 51/60 patients (85 %)). There were no major complications in both groups. Conclusions In patients with an initial circumferential PVI using the cryoballoon technique, a repeat ablation procedure can be performed safely and effectively using radiofrequency catheter ablation. In most cases only a few re-conducting PV fibers were found and therefore, a segmental re-ablation approach seems to be sufficient in the majority of patients (especially in patients treated with the second generation cryoballoon).

Depression and recurrence of atrial fibrillation after catheter ablation: a meta-analysis of cohort studies

Background: The influence of depression on the recurrence of atrial fibrillation (AF) after catheter ablation remains unclear. We performed a meta-analysis to evaluate the association between depression and AF recurrence after catheter ablation. Methods: Cohort studies that evaluated depression at baseline and correlated depression with AF recurrence after catheter ablation were identified by searching the PubMed and Embase databases. Heterogeneity was determined using the Cochrane's Q test and calculating the I2 statistic. A random-effect model was applied to incorporate the potential influence of heterogeneity. Results: Our analysis included seven cohort studies with 1,070 AF patients who underwent catheter ablation by circumferential pulmonary vein isolation. No significant heterogeneity was detected among the included studies (p for Cochrane's Q test = 0.20, I2 = 29%). Pooled results showed that depression before procedure was independently associated with increased risk of AF recurrence after catheter ablation (adjusted relative risk [RR]: 2.24, 95% confidence interval [CI]: 1.75 - 2.88, p < 0.001). Sensitivity analyses, conducted by omitting one study at a time, retrieved similar results (RR: 2.06 - 2.53, p all < 0.05). Predefined subgroup analyses showed that the association between depression and AF recurrence after catheter ablation was consistent regardless of the study characteristics, including study location, study design, patient number, type of AF, follow-up duration, adjustment of left atrial dimension, and quality score. Limitations: This analysis included a limited number of studies and various instruments applied to measure depression. Conclusions: Depression is an independent risk factor of AF recurrence after catheter ablation.

Clinical efficacy of "ICE-FIRE" ablation for non-paroxysmal atrial fibrillation.

Catheter ablation is less successful for non-paroxysmal atrial fibrillation (NPAF) according to numerous follow-up studies. The choice of ablation strategy for patients with NPAF remains controversial. The objective of the study was to explore the clinical efficacy of the "ICE-FIRE" ablation. Ninety NPAF patients were enrolled. Patients were randomly divided into RF (treated with circumferential pulmonary vein isolation (CPVI) and additional substrate modification by radiofrequency ablation) group and I-F (treated with CPVI by cryoablation and additional substrate modification by radiofrequency ablation) group. After CPVI and cardioversion to sinus rhythm, high-density mapping was performed. Eight-one of 90 participants restored to sinus rhythm. Seventy-four of 81 NPAF patients showed low-voltage zone. Substrates with low-voltage zone were targeted for further modification. Participants were followed at baseline, 3, 6, 9, and 12months after the initial ablation. The I-F group shared more X-ray exposure (I-F, 264.4 ± 97.4mGy; RF, 224.9 ± 62.0mGy; P = 0.039) and less duration of the procedure (I-F, 150.3 ± 27.5min; RF, 174.2 ± 38.5min; P = 0.003) compared to RF group. The freedom from atrial arrhythmia recurrence at 12months post-ablation was similar between the RF and I-F groups (RF, 57.1%; I-F, 71.8%; P = 0.197). However, I-F group experienced lower rehospitalization rate of AF recurrence (RF, 42.9%; I-F, 20.5%; P = 0.038). In NPAF patients requiring substrate mapping and modification, the "ICE-FIRE" ablation demonstrated non-inferior clinical efficacy and lower rehospitalization rate of AF recurrence when compared with pure radiofrequency ablation strategy.

Is Catheter Ablation Better Than Antiarrhythmic Drugs for the Treatment of Atrial Fibrillation?

Long-standing atrial fibrillation is associated with significant morbidity including stroke and development of heart failure. Patients also report poor quality of life as a result of debilitating symptoms or treatment side effects from antiarrhythmic medications. Radio frequency or cryothermal mediated catheter ablation has a central role in the management of symptomatic patients with paroxysmal or persistent atrial fibrillation. Circumferential pulmonary vein isolation is vital to the success of this therapy and other ancillary techniques have been described, especially for persistent atrial fibrillation. Several randomized controlled studies have been reported over the last two decades studying important clinical outcomes in patients with atrial fibrillation. In this article, we aim to provide a review of the major studies that have helped define the role of catheter ablation in the management of symptomatic atrial fibrillation in patients with both diseased and structurally normal hearts.

A square root pattern of changes in heart rate variability during the first year after circumferential pulmonary vein isolation for paroxysmal atrial fibrillation and their relation with long‑term arrhythmia recurrence.

An incidental lesion of the parasympathetic ganglia during circumferential pulmonary vein isolation (CPVI) may affect heart rate variability (HRV). We studied the pattern of changes in HRV parameters and the relationship between the 1‑year HRV change following CPVI and the recurrence of atrial fibrillation (AF). A total of 100 consecutive patients undergoing CPVI for paroxysmal AF were enrolled (mean [SD] age, 56 [11.2] years; 61 men). We measured HRV on the day before and after CPVI, and then at 1 month as well as 3, 6, and 12 months after CPVI using 24‑hour Holter monitoring. During the median follow‑up of 33 months, 38 patients experienced the late recurrence of AF (LRAF). Compared with the pre‑CPVI values, HRV was significantly attenuated on day 1 after CPVI in all patients. However, at 3 to 6 months after CPVI, all HRV parameters remained significantly decreased in LRAF‑free patients but not in those with LRAF. The multivariate Cox analysis showed that early AF recurrence within the blanking period (hazard ratio [HR], 4.87; 95% CI, 2.44–9.69; P <0.001) and a change in the standard deviation of normal‑to‑normal intervals (SDNN) observed 3 months after ablation (HR, 0.99; 95% CI, 0.98–1; P = 0.01) were associated with LRAF. The cumulative LRAF freedom after CPVI was greater in patients with an SDNN reduction of more than 25 ms reported 3 months after ablation than in those with a reduction of 25 ms or lower (log‑rank P = 0.004). Sustained parasympathetic denervation during 12 months after CPVI was a marker of successful CPVI, whereas a 3‑month post‑CPVI SDNN reduction of 25 ms or lower predicted LRAF.

Circumferential pulmonary vein antrum ablation for the treatment of paroxysmal atrial fibrillation: A randomized controlled trial.

It remains unclear whether the curative result of paroxysmal atrial fibrillation (PAF) is a result of pulmonary vein (PV) isolation, PV antrum modification (PVAM), or both. We hypothesized that sufficient antrum modification (PVAM) is as important as PV isolation (PVI) for atrial fibrillation (AF) control and that PVAM can be evaluated by quantified lesion deployment using a force-sensing catheter. Patients of symptomatic PAF were randomly assigned 2:1 into a PVAM group or a circumferential PV isolation (CPVI) group. In the PVAM group, circumferential quantitative ablation evaluated by automatical VisiTag module was performed. In the CPVI group, conventional circumferential ablation was performed to achieve the end point of all-PV isolation. In total, 180 patients with PAF were enrolled and randomly assigned to either the PVAM group (n=120) or the CPVI group (n=60). A total of 179 patients successfully underwent ablation. In the PVAM group, 68 patients achieved all PVI (PVAM-PVI), while 51 did not (PVAM-non-PVI). At 18 months, there was no significant difference in the maintenance of sinus rhythm between the PVAM and CPVI groups (84.9vs 79.7%, P=.382). The PVAM-PVI subgroup demonstrated a higher arrhythmia-free survival compared with the PVAM-non-PVI subgroup (92.6vs 74.5%, P=.006) and the CPVI group (92.6 vs 79.7%, P=.036). The trial shows that sufficient force-sensing guided PVAM can result in satisfying outcomes in PAF patients. Notably, sufficient PVAM with all-PV isolated will further increase the success rate.

Segmental Versus Circumferential Ablation of Pulmonary Veins in Patients with Paroxysmal Atrial Fibrillation

INTRODUCTION: Pulmonary vein isolation (PVI) is the cornerstone of catheter ablation techniques for the treatment of paroxysmal atrial fibrillation (PAF), with significantly improved efficacy compared to antiarrhythmic drugs as shown in CABANA trial. However, the question arises in which PAF patients whether the procedure can be limited to PVs only showing potentials (segmental), or it is really necessary to isolate all PV (circumferential). Even though success rates for circumferential PV ablation (CPVA) have been reported to be higher (up to 90%), than segmental PV ablation, most CPVA procedures previously reported included left atrial linear ablation, additional ablation lesions or lines connecting the mitral valve to the posterior PVs or along the roof of the left atrium which made bias to these studies.&#x0D; AIM: Thus, we initiated this randomized controlled study to evaluate the efficacy of CPVA versus SPVI in subjects undergoing ablation of PAF.&#x0D; METHODS: Our study included 31 consecutive patients who underwent their first radiofrequency ablation for PAF between March 2015 and March 2017. Patients were randomized for circumferential or segmental ablation on the day of the procedure. We had two groups, circumferential (17 patients) and segmental group (14 patients).&#x0D; RESULTS: There was no difference between two groups on our primary endpoint, the recurrence, which was 2 out of 14 patients (14.3%) in the segmental ablation group, compared to 3 out of 17 patients (17.6%) who were circumferential ablated. This difference is statistically insignificant (p = 1). For other endpoints, there was also no statistically significant difference between circumferential and segmental regarding fluoroscopy time, 53.47 ± 8.7 min versus 54.93 ± 15.02 min, p = 0.738, procedure time, 184.18 ±19.28 min versus 191.43 ± 20 min p = 0.315, and even for radio frequency time which was lower in segmental group but did not differ statistically, 35.71 ± 5.73 min versus 34.79 ± 5.29, min p = 0.649.&#x0D; CONCLUSION: The previous studies showed the superiority of circumferential PVI on segmental strategy regarding effectiveness, but in those studies, linear ablations were added to circumferential strategy and done in cases of persistent and PAF. In our randomized study, we compared between two methods in cases of PAF, which showed that segmental ablation is not inferior to circumferential ablation of PVI.

Homogenization of low voltage aereas for the ablation of persistent atrial fibrillation

Current ablation strategies for persistent AF have shown a limited success rate with frequent arrhythmia recurrences. STAR-AF 2 trial assessed that PVI-only is as effective as other ablation strategies. Recent studies suggest that the atrial arrhythmogenic sites are related to regions with heterogeneities and increased fibrosis which is detected by reduced bipolar voltage areas. Targeting low voltage areas in addition to PVI may represent an efficient strategy for the ablation of persistent AF. We prospectively included patients with symptomatic persistent AF (mean age: 60.8 ± 4.2 years, men 78%). The ablation strategy consisted of circumferential pulmonary vein isolation (CPVI). Sinus rhythm was restored by electrical cardioversion. A voltage map was performed in sinus rhythm. Complementary RFA was guided by low voltage areas (0.2–0.4 mV). Success was defined as freedom from AF/atrial flutter or atrial arrhythmia for a period ranging from 3 months to 12 months or more. 55 patients were included with persistent AF. Procedure time was: 154 ± 25 min and fluoroscopy time: 184 ± 90 sec. Time of RFA was 44.7 ± 12.7 min. Mean LA volume was 195 ± 35 mL. Low voltage areas were identified in 41.5% of pts. AF was not inducible for 81.8% of pts. After a single procedure at a mean FU of 12 months, 71% of patients were free of symptomatic AF. Predictive factors of recurrence of AF were large left atrial volume (> 205 mL), shorts AF cycle length (< 168 ms) and reduce LEVF (< 45%). 5.5% of the pts presented atrial tachycardia, and re-ablated with success. These results suggest that PVI with complementary RF ablation guided on low voltage areas is an efficient strategy for symptomatic persistent AF.

Acute and long-term ablation results of extra pulmonary vein drivers detected by ultra high density mapping on top of PVI in persistent AF

Whether ultra-high density (UHD) contact mapping is useful in radiofrequency ablation of persistent atrial fibrillation (AF) is unknown. To sequentially map the left atrial (LA) activation during AF ablation (circumferential PVI and ablation of extra pulmonary vein drivers). Time reference was an LA appendage (LAA) electrogram (EGM). Points were acquired with respiratory gating if reference, cycle length (10 ms tolerance) and electrode location were stable. For fragmented EGM the timing of the surrounding area was used. In case of extremely low voltage (< 0.01 mV) or lack of local statistical coherence no colour-code was displayed (grey area). Circular propagation around single points was defined as organized rotating drivers ( Fig. 1 ). All pts had PVI followed by remapping and ablation of the centre of rotational regions and at sites with focal type propagation. DC or chemical cardioversion were not performed in the first 48 h. Out of 41 patients (pts) undergoing first time ablation with the above described protocol, 30 (66 ± 8 y, mean current episode duration 8 months) were followed for a mean time of 14,7 months. At 48 hours post-procedure, 70% of pts were no longer in AF: 6 (20%) in sinus rhythm and 15 (50%) in atrial tachycardias. At 1 year after a single procedure, freedom from AF was 87% and freedom from AF and AT was 60% ( Fig. 1 ). In persistent AF, sequential UHD activation mapping is useful in guiding and potentially improving long-term results of ablation of extra pulmonary vein drivers after PVI.

The mechanisms of recurrent atrial arrhythmias after second-generation cryoballoon ablation

In patients with paroxysmal atrial fibrillation (PAF), 10%-15% of patients require repeat procedures after second-generation cryoballoon pulmonary vein isolation (CB-PVI). We sought to explore the mechanisms of recurrences after cryoballoon ablation. The data of 122 PAF patients who underwent second procedures for recurrent arrhythmias 7.0 (4.0-12.0) months after the CB-PVI were analyzed. During second procedures, non-PV AF foci were explored with isoproterenol, adenosine, and repetitive cardioversions. In total, 378/487 (77.6%) PVs remained isolated, and reconnections were not observed in any PVs in 59 (48.4%) patients. PV reconnections were associated with recurrences in 38 (31.1%) patients, of whom 33 (86.8%) had reconnections of at least 1 upper PV. In 6 (4.9%) patients, non-PV AF foci were identified in the upper PV antra where cryoballoons cannot isolate but within the circumferential radiofrequency PVI line. Non-PV AF foci were identified in the superior vena cava, right atrial body, left atrial body, and atrial septum in 28 (23.0%), 18 (14.7%), 4 (3.3%), and 5 (4.1%) patients, respectively. Twelve (9.8%) patients had multiple non-PV AF foci. Four (3.3%), 3 (2.4%), and 8 (6.5%) patients underwent second procedures for atrioventricular nodal reentrant tachycardia, atrial flutter, and atrial tachycardias. During 16.0 (8.0-24.0) months of follow-up, freedom from any atrial arrhythmia at 1 year and 2 years after the second procedure was 79.2% and 60.6%. Nineteen (15.5%) patients had antiarrhythmic drug therapy at the last follow-up. Our study suggested that improvement in the upper PV PVI durability, eliminating arrhythmogenic superior vena cavae and coexisting atrial arrhythmias, and bonus cryoballoon applications at PV antra might improve the single procedure outcome in cryoballoon ablation.

Amplified sinus-P-wave reveals localization and extent of left atrial low-voltage substrate: implications for arrhythmia freedom following pulmonary vein isolation.

Presence of arrhythmogenic left atrial (LA) low-voltage substrate (LVS) is associated with reduced arthythmia freedom rates following pulmonary vein isolation (PVI) in persistent atrial fibrillation (AF). We hypothesized that LA-LVS modifies amplified sinus-P-wave (APW) characteristics, enabling identification of patients at risk for arrhythmia recurrences following PVI. Ninety-five patients with persistent AF underwent high-density (>1200 sites) voltage mapping in sinus rhythm. Left atrial low-voltage substrate (<0.5 and <1.0 mV) was quantified in a 10-segment LA model. Amplified sinus-P-wave-morphology and -duration were evaluated using digitized 12-lead electrocardiograms (40-80 mm/mV, 100-200 mm/s). 12-months arrhythmia freedom following circumferential PVI was assessed in 139 patients with persistent AF. Left atrial low-voltage substrate was most frequently (84%) found at the anteroseptal LA. Characteristic changes of APW were related to the localization and extent of LA-LVS. At an early stage, LA-LVS predominantly located to the LA-anteroseptum and was associated with APW-prolongation (≥150 ms). More extensive LA-LVS involved larger areas of LA-anteroseptum, leading to morphological changes of APW (biphasic positive-negative P-waves in inferior leads). Severe LA-LVS involved the LA-anteroseptum, roof and posterior LA, but spared the inferior LA, lateral LA, and LA appendage. In this advanced stage, widespread LVS at the posterior LA abolished the negative portion of P-wave in the inferior leads. The delayed activation of the lateral LA and LA appendage produced the late positive deflections in the anterolateral leads, resulting in the "late-terminal P"-pattern. Structured analysis of APW-duration and -morphology stratified patients to their individual extent of LA-LVS (Grade 1: mean LA-LVS 4.9 cm2 at <1.0 mV; Grade 2: 28.6 cm2; Grade 3: 42.3 cm2; P < 0.01). The diagnostic value of APW-duration for identification of LA-LVS was significantly superior to standard P-wave-amplification (c-statistic 0.945 vs. 0.647). Arrhythmia freedom following PVI differed significantly between APW-predicted grades of LA-LVS-severity [hazard ratio (HR) 2.38, 95% confidence interval (CI) 1.18-4.83; P = 0.015 for Grade 1 vs. Grade 2; HR 1.79, 95% CI 1.00-3.21, P = 0.049 for Grade 2 vs. Grade 3). Arrhythmia freedom 12 months after PVI was 77%, 53%, and 33% in Grades 1, 2 and 3, respectively. Localization and extent of LA-LVS modifies APW-morphology and -duration. Analysis of APW allows accurate prediction of LA-LVS and enables rapid and non-invasive estimation of arrhythmia freedom following PVI.

Avoidance of Vagal Response During Circumferential Pulmonary Vein Isolation: Effect of Initiating Isolation From Right Anterior Ganglionated Plexi.

Circumferential pulmonary vein isolation (CPVI) often cause unavoidable vagal reflexes during procedure due to the coincidental modification of ganglionated plexus which are located on pulmonary vein (PV) antrum. The right anterior ganglionated plexi (RAGP) which located at superoanterior area of right superior PV antrum is an essential station to regulate the cardiac autonomic nerve activities and is easily coincidentally ablated during CPVI. The aim of this study is to assess the effect of RAGP ablation on vagal response (VR) during CPVI. A total of 80 patients with paroxysmal atrial fibrillation who underwent the first time CPVI were prospectively enrolled and randomly assigned to 2 groups: group A (n=40), CPVI started with right PVs at RAGP site; group B (n=40): CPVI started with left PVs first, and the last ablation site is RAGP. Electrophysiological parameters include basal cycle length, A-H interval, H-V interval, sinus node recovery time, and atrioventricular node Wenckebach point were recorded before and after CPVI procedure. During CPVI, the positive VR were only observed on 1 patient in group A and 25 patients in group B (P<0.001). A total of 21 patients with positive VR in group B needed for temporary ventricular pacing during procedure, while the only patient with positive VR in group A did not need for temporary ventricular pacing (P<0.001). Compared with baseline, basal cycle length, sinus node recovery time, and atrioventricular node Wenckebach point were decreased significantly after CPVI procedure in both groups (all P<0.05) and without differences between 2 groups. Circumferential PV isolation initiated from RAGP could effectively inhibit VR occurrence and significantly increase heart rate during procedure.