Pulmonary Vein Isolation For Paroxysmal Atrial Fibrillation Research Articles

Lesion characteristics using high-frequency low-tidal volume ventilation versus standard ventilation during ablation of paroxysmal atrial fibrillation.

High-frequency low-tidal-volume (HFLTV) ventilation during radiofrequency catheter ablation (RFCA) for paroxysmal atrial fibrillation (PAF) has been shown to be superior to standard ventilation (SV) in terms of procedural efficiency, acute and long-term clinical outcomes. Our study aimed to compare ablation lesions characteristics utilizing HFLTV ventilation versus SV during RFCA of PAF. A retrospective analysis was conducted on patients who underwent pulmonary vein isolation (PVI) for PAF between August 2022 and March 2023, using high-power short-duration ablation. Thirty-five patients underwent RFCA with HFLTV ventilation and were matched with another cohort of 35 patients who underwent RFCA with SV. Parameters including ablation duration, contact force (CF), impedance drop, and ablation index were extracted from the CARTONET database for each ablation lesion. A total of 70 patients were included (HFLTV = 35/2484 lesions, SV = 35/2830 lesions) in the analysis. There were no differences in baseline characteristics between the groups. While targeting the same ablation index, the HFLTV ventilation group demonstrated shorter average ablation duration per lesion (12.3 ± 5.0 vs. 15.4 ± 8.4 s, p < .001), higher average CF (17.0 ± 8.5 vs. 10.5 ± 4.6 g, p < .001), and greater impedance reduction (9.5 ± 4.6 vs. 7.7 ± 4.1 ohms, p < .001). HFLTV ventilation group also demonstrated shorter total procedural time (61.3 ± 25.5 vs. 90.8 ± 22.8 min, p < .001), ablation time (40.5 ± 18.6 vs. 65.8 ± 22.5 min, p < .001), and RF time (15.3 ± 4.8 vs. 22.9 ± 9.7 min, p < .001). HFLTV ventilation during PVI for PAF was associated with improved ablation lesion parameters and procedural efficiency compared to SV.

Early recurrence of atrial tachyarrhythmia indicates pulmonary vein reconduction independent of blanking period duration in the RACE-AF trial.

Atrial tachyarrhythmia recurrence during the blanking period (early ATA) after pulmonary vein isolation (PVI) is associated with an increased risk of later recurrence, but its relationship with pulmonary vein reconduction (PVR) is poorly understood. The objective of the present study was to evaluate the relationship between early ATA and PVR. Second, to provide data on the optimal blanking period by (a) evaluating how the predictive values of ATA for PVR are affected by blanking period duration, and (b) assessing the temporal development in atrial fibrillation (AF) burden. In this RACE-AF substudy, 91 patients with paroxysmal AF undergoing PVI randomized to radiofrequency or cryoballoon ablation were included. All patients received an implantable cardiac monitor and underwent a protocol-mandated repeat procedure after 4-6 months for assessment of PVR. ATA ≥ 30 s. ≤ 90 days after PVI constituted early ATA. PVR was found in 37/54 (69%) patients with early ATA and in 11/37 (30%) patients without (p < .001). The positive predictive value of ATA for PVR was independent of blanking period duration (range 0-90 days). In both patients with and without PVR, AF burden was higher in the first month after PVI, but AF burden from the second month was similar to AF burden after the conventional blanking period. Early ATA indicates PVR, and the positive predictive value is independent of the blanking period duration. Altogether, the results of this study support substantially shortening the blanking period after PVI for paroxysmal AF.

Temperature-controlled high-power short-duration ablation with 90W for 4s: outcome, safety, biophysical characteristics and cranial MRI findings in patients undergoing pulmonary vein isolation.

High-power short-duration (HPSD) radiofrequency ablation (RFA) is highly efficient and safe while reducing procedure and RF time in pulmonary vein isolation (PVI). The QDot™ catheter is a novel contact force ablation catheter that allows automated flow and power adjustments depending on the local tissue temperature to maintain a target temperature during 90W/4s lesions. We analysed intraprocedural data and periprocedural safety using the QDot-catheter in patients undergoing PVI for paroxysmal atrial fibrillation (PAF). We included n = 48 patients undergoing PVI with the QDot-catheter with a temperature-controlled HPSD ablation mode with 90W/4s (TC-HPSD). If focal reconnection occurred besides repeat ablation, the ablation mode was changed to 50W/15s (QMode). N = 23 patients underwent cerebral MRI to detect silent cerebral lesions. Mean RF time was 8.1 ± 2.8min, and procedure duration was 84.5 ± 30min. The overall maximal measured catheter tip temperature was 52.0°C ± 4.6°C, mean overall applied current was 871mA ± 44mA and overall applied energy was 316J ± 47J. The mean local impedance drop was 12.1 ± 2.4 Ohms. During adenosine challenge, n = 14 (29%) patients showed dormant conduction. A total of n = 24 steam pops were detected in n = 18 patients (39.1%), while no pericardial tamponade occurred. No periprocedural thromboembolic complications occurred, while n = 4 patients (17.4%) showed silent cerebral lesion. TC-HPSD ablation with 90W/4s using the QDot-catheter led to a reduction of procedure and RF time, while no major complications occurred. Despite optimized temperature control and power adjustment, steam pops occurred in a rather high number of patients, while none of them leads to tamponade or to clinical or neurological deficits.

2-year outcomes of phased radiofrequency ablation for atrial fibrillation with the second-generation PVAC Gold ablation catheter

PurposeThe second-generation multi-electrode catheter, PVAC Gold, was designed to improve the safe delivery of phased radiofrequency energy using a “single shot” approach for pulmonary vein isolation (PVI), while retaining efficacy. This large registry presents long-term performance in a daily practice setting.MethodsA total of 1011 patients undergoing first time ablation for atrial fibrillation (AF) using PVAC Gold were included, 639 patients with PVI for paroxysmal AF (PAF PVI) and 372 patients with persistent or long-standing persistent AF, divided into 175 patients receiving PVI only (PersAF PVI) and 197 patients receiving PVI with additional substrate ablation (PersAF PVI +).ResultsAt 24-month follow-up, single procedure freedom from atrial tachyarrhythmia (ATA) was 58% (368/639) in the PAF PVI group, 44% (77/175) in the PersAF PVI group, and 29% (57/197) in the PersAF PVI + group. Allowing one repeat procedure in 33% of patients, 76%, 65%, and 54% were free from ATA at 24 months, respectively. Pulmonary vein reconnection was observed in 98% of patients with recurrent arrhythmia after PVI.ConclusionsAlthough phased RF ablation with PVAC Gold is quick and safe, the efficacy outcomes are modest compared to current mainstream ablation strategies.

Is there a change in P wave parameters following pulmonary vein isolation (PVI) using radiofrequency ablation (RF) vs. cryoballoon ablation (CRYO) for paroxysmal atrial fibrillation (PAF)?

Abstract Funding Acknowledgements Type of funding sources: None. Pulmonary vein isolation (PVI) is an effective and established therapy for paroxysmal atrial fibrillation (PAF) . PVI can be performed using point by point ablation with radiofrequency (RF) or with single shot techniques such as cryoballoon (CRYO). As P waves represent atrial depolarization, we aimed to study whether P wave metrics may change after PVI and if there are differences between RF and CRYO approaches. Methods We studied 88 matched patients who had PVI for PAF between January 2017 and December 2018 (RF = 44, CRYO = 44). Each patient was in sinus rhythm (SR) prior to ablation. Patients on amiodarone and those who had additional linear ablation were excluded. Patients had continuous ECG monitoring using Labsystem Pro (Boston Scientific Inc). Sampled at 1kHz during the procedure. One-minute recordings before and after PVI were exported and analysed using custom-written software using MatLab (v2018, bandpass 1-50Hz) to annotate P wave onset, peak and end. P wave duration was heart rate corrected (PWDc) by using the Hodges formula and P wave amplitude (PWA). Results P wave metrics were comparable before PVI between both cohorts. Successful PVI was achieved in all patients. There was a trend towards an increase in PWDc in some ECG leads with either RF or CRYO but no significant difference in P wave metrics as a result of PVI ablation or between both ablation modalities. Conclusion In this study, there was no significant change seen in PVI with RF or CRYO and no difference between the 2 ablation modalities. P wave metrics comparison, RF vs CRYO PWDc (ms) PRE, RF (n = 44) POST, RF (n = 44) P PRE, CRYO (n = 44) POST CRYO (n = 44) P P (RF vs CRYO) I 134.7 ± 32 133.5 ± 35 0.813 131.9 ± 36 132.7 ± 39 0.9 0.81 II 140.9 ± 34 144.1 ± 37 0.56 139.4 ± 42 134.4 ± 40 0.51 0.41 III 131.5 ± 31 143.3 ± 37 0.04 132.8 ± 41 130.6 ± 36 0.68 0.074 AVF 137 ± 32 144.7 ± 36 0.15 137.5 ± 42 127.4 ± 37 0.11 0.141 V1 143.9 ± 33 151.8 ± 37 0.17 133.6 ± 37 143.8 ± 38 0.09 0.745 PWA (mV) PRE, RF (n = 44) POST, RF (n = 44) P PRE, CRYO (n = 44) POST CRYO (n = 44) P P (RF vs CRYO) I 0.125 ± 0.08 0.09 ± 0.06 0.002 0.13 ± 0.08 0.14 ± 0.09 0.59 0.076 II 0.238 ± 0.1 0.238 ± 0.1 0.98 0.232 ± 0.1 0.278 ± 0.2 0.1 0.212 III 0.149 ± 0.1 0.153 ± 0.1 0.83 0.189 ± 0.1 0.187 ± 0.1 0.97 0.86 AVF 0.195 ± 0.1 0.196 ± 0.1 0.92 0.197 ± 0.1 0.247 ± 0.1 0.066 0.132 V1 0.122 ± 0.1 0.151± 0.1 0.05 0.138 ± 0.1 0.193 ± 0.2 0.002 0.543 PWDc and PWA comparison following RF vs CRYO.

Change in the local impedance and electrograms recorded by a micro-electrode tip catheter during initial atrial fibrillation ablation.

BackgroundA novel measurement of the local impedance (LI) and electrograms recorded from micro‐electrodes on catheter tip has been developed. However, the data during pulmonary vein (PV) ablation is not sufficient. We aimed to investigate the utility of this measurement during initial atrial fibrillation (AF) ablation.MethodsWe investigated 111 representative radiofrequency applications in 7 AF patients without a history of prior ablation (6 males, age 68 [65‐72] years, 2 persistent AF). The ablation strategy was PV isolation for paroxysmal AF and single ring box isolation for persistent AF, using MiFi catheter. The correlation of the generator impedance (GI) drop and LI drop after radiofrequency applications and the predictive value of the initial LI elevation before radiofrequency applications for LI drop were analyzed. Also, the LI and GI drop were investigated according to the location of RF applications.ResultsThe LI drop was higher than GI drop (23.7 [16.4‐35.7] and 9.0 [6.0‐12.0]; P < .01). There were correlations between the initial LI elevation and LI drop (R 2 = 0.466, P < .01) and between the LI and GI drop (R 2 = 0.263, P < .01). The LI drops significantly differed according to the different anatomical localizations by the Kruskal–Wallis test, although the GI drops did not differ (P < .01 and P = .49, respectively)ConclusionLI drop was associated with initial LI elevation and was larger than GI drop. LI drop was different according to locations, although GI drop was not. These findings might indicate that LI drop would be a more sensitive marker for lesion formation than GI drop.

Association of pericardial effusion after pulmonary vein isolation and outcomes in patients with paroxysmal atrial fibrillation.

The clinical implications of pericardial effusion (PE) after catheter ablation for atrial fibrillation (AF) are not well understood. We evaluated the association between newly developed PE after pulmonary vein isolation (PVI) for paroxysmal AF and arrhythmic recurrence. From a prospective AF ablation registry, 184 patients (mean age 59 ± 10 years, 65% male) who underwent first-time PV isolation using a smart touch surround flow catheter (Biosense Webster, Diamond Bar, CA) were analyzed. Postablation transthoracic echocardiography (TTE) was performed within 1-3 days after ablation, and the occurrence of PE was assessed. PE developed in 91 patients (49.5%), and most were of minimal severity (minimal, 93.4%; mild, 6.6%). Patients with PE had significantly lower body mass index and underwent cavotricuspid isthmus ablation more frequently. Early arrhythmic recurrence (EAR) (within 3 months) was observed in 28.8% of patients and was not different according to the PE development (PE [+]: 29.7%vs PE [-]: 28.0%; P=.80). During a median follow-up of 696 days, the cumulative rate of the late arrhythmic recurrence (LAR) (after 3 months) was 36.4%, and there was no difference between groups (PE [+]: 36.7%vs PE [-]: 35.1%; P=.988). The only predictor of LAR was EAR, and no echocardiographic parameters showed a significant correlation with LAR. Minimal or mild PE after PVI for paroxysmal AF is a frequent echocardiographic finding, and it had no significant association with AF recurrence. Routine TTE after AF ablation has no clinical implication.

Effect of Combined Pulmonary Vein and Superior Vena Cava Isolation on the Outcome of Second Catheter Ablation for Paroxysmal Atrial Fibrillation

Recurrence of paroxysmal atrial fibrillation (AF) is partly due to pulmonary vein (PV) reconnection and non-PV foci, especially superior vena cava (SVC). We aimed to investigate the efficacy and safety of empiric SVC isolation plus PV isolation after first failed radiofrequency ablation involving only PV isolation for paroxysmal AF. Procedural and follow-up outcomes of ablation for 144 consecutive paroxysmal AF patients after first failed radiofrequency ablation involving only PV isolation were retrospectively compared between patients undergoing either conventional SVC isolation (additional SVC isolation if SVC-triggered AF or rapid SVC activity was observed; n = 72) or empiric SVC isolation after PV isolation (n = 72). In conventional SVC isolation versus empiric SVC isolation groups: baseline characteristics and proportion of recorded PV electrical potentials were similarly distributed and all pulmonary veins were successfully reisolated; SVC isolation was performed less often (6 [8.3%] vs 70 [97.2%]; p <0.001, respectively); and during 19 ± 10 months follow-up, atrial tachyarrhythmias recurrence-free rate after a second procedure was lower (58.3% vs 77.8%, log rank; p = 0.037). Multivariate regression analysis revealed LA diameter ≥45 mm (odds ratio [OR] = 2.5; 95% confidence interval [CI], 1.4 to 4.6; p = 0.002) as the independent risk factor of atrial tachyarrhythmias recurrence and empiric SVC isolation (OR = 0.47; 95% CI, 0.25 to 0.87; p = 0.016) as the independent protector against atrial tachyarrhythmias recurrence after a second ablation procedure. Empiric SVC isolation plus PV isolation did not increase significantly procedural time or complications. In conclusion, the strategy of empiric SVC isolation plus PV isolation during a second procedure for paroxysmal AF improved atrial tachyarrhythmias recurrence-free rate without increasing procedural time or complications.

Is there a difference in rhythm outcome between patients undergoing first line versus second line paroxysmal atrial fibrillation ablation?

BackgroundCatheter ablation of atrial fibrillation (AF) is an established second line therapy for patients with symptomatic paroxysmal AF (PAF) and may be considered as a first line therapy in selected patients who are highly symptomatic, considering patient choice, benefit, and risk, according to recent guidelines. Our study investigated whether a first line vs. second line ablation approach may result in improved sinus rhythm maintenance after ablation.MethodsA total of 153 patients undergoing pulmonary vein isolation for PAF were included in the study (age 55±12 years, 29% female). Seventy-nine patients underwent first line AF ablation and 74 patients underwent second line AF ablation after failed antiarrhythmic drug therapy. There was no significant difference in baseline characteristics such as age, history of AF, left atrial size or LVEF between groups. Success was defined as atrial tachyarrhythmia free survival during a 12-month follow-up by means of serial ECG Holter monitoring.ResultsThere was no significant difference in cumulative arrhythmia-free survival between those patients who received AF ablation as a first or second line therapy. Single procedure success was 78% in the first line group vs. 81% in the second line group; multiple procedure success was 90 vs. 91%, (n.s.). Complication rate was 1.3% vs. 1.4% (n.s.).ConclusionSuccess of AF ablation did not differ between patients who receive ablation as first vs. second line therapy. Based on these data, a trial of AAD therapy before AF ablation may be justified in most patients with symptomatic PAF eligible for rhythm control.

Anatomic Parameters Predicting Procedural Difficulty and Balloon Temperature Predicting Successful Applications in Individual Pulmonary VeinsDuring 28-mm Second-Generation Cryoballoon Ablation.

This study sought to identify anatomic parameters predicting procedural difficulty in achieving pulmonary vein isolation (PVI) and in-procedural predictors of successful applications during second-generation cryoballoon (CB) ablation. PV anatomies vary and influence the procedural difficulty during CB PVI. In total, 408 initial freezes among 110 patients undergoing PVI for paroxysmal atrial fibrillation using 28-mm second-generation CBs with single 3-min freeze techniques were included. The anatomic parameters were obtained from pre-procedural cardiac computed tomography. The nadir balloon temperature and temperature at the start of the plateau phase were recorded during each freeze. Acute PVI was achieved by initial applications in 335 pulmonary veins (PVs) (82.1%) and touch-up was required in 13 (3.2%). A multivariate analysis revealed that a thinner left lateral ridge (<4.7 mm), higher ovality (>50.5%), and longer PV ostium-bifurcation distance (>26.1 mm) required multiple applications for a successful left superior PVI. Older age (>68 years), and shorter PV ostium-bifurcation distance (<10.4 mm) required multiple applications for a successful right superior and right inferior PVI, respectively. Shorter PVTLs were also associated with requiring touch-up of the RIPV. Balloon temperatures were lower for successful than failed PVI applications. Successful PVIs were predicted using the nadir balloon temperature at 33.0 ± 2.6 s, 33.0 ± 2.5 s, 33.6 ± 2.5 s, and 33.0 ± 2.5 s from the initiation of freezes with positive predictive values of 87.7%, 88.5%, 98.5%, and 81.6% using cutoff temperatures of -34°C, -33°C, -37°C, and -33°C in the left superior, left inferior, right superior, and right inferior PVs, respectively. The anatomic information might predict procedural difficulty and the balloon temperature a successful PVI during the early CB ablation freezing phase.

Early Pulmonary Vein Conduction Recovery after Catheter Ablation of Atrial Fibrillation.

Pulmonary vein electrical isolation (PVI) is an effective treatment for atrial fibrillation (AF). However, recurrence of pulmonary vein (PV) conduction after ablation may limit long-term success. Early identification and treatment of acute PV conduction recovery during initial ablation may have an impact on subsequent clinical results. To assess the prevalence of acute PV conduction recovery during the observation time after PV isolation for paroxysmal AF, and to evaluate the impact of re-isolation treatment on long-term clinical results. 76 patients with paroxysmal AF were randomized to 2 groups to undergo PVI. Group A (Study Group: 38 patients): 30 minutes of observation were given following PV isolation for detection of acute PV-reconnection, with re-ablation of reconnected PVs. Group B (Control Group: 38 patients). Ablation procedure was done either by conventional method or using 3D electro-anatomical mapping. Symptoms, ECG and Holter monitoring were used to evaluate the clinical effectiveness of ablation. Any episode of symptomatic or asymptomatic atrial tachyarrhythmia that lasted more than 30 seconds documented with ECG or Holter monitoring was considered a recurrence. There was no statistically significant difference in age, sex, AF history, previous AF ablation, structural heart diseases & antiarrhythmic drug history among both groups. In the study group, 14 patients (36.8%) showed no PV reconnection, while 24 patients (63.2%) showed acute PV reconnection within 30 minutes. The LSPV showed the highest rate of acute PV reconnection during the observation period (66.6% of patients showing PV reconnection). AF recurred in only 6 patients (15.8%) in the study group in comparison to 20 patients (52.6%) having AF recurrence post-ablation in the control group. Among 24 patients of the study group, who showed PV reconnection which was re-isolated, only 4 patients (16.7%) had AF recurrence on follow up. In patients who did not show PV reconnection (14 patients), only 2 patients (14.3%) had AF recurrence on follow up. Re-isolation of recovered PV conduction contributed to the improvement in the success rate of ablation for paroxysmal AF.

Abstract 18649: Long-term Outcome and the Mechanisms of Pulmonary Antrum Radial-linear Ablation in Patients With Paroxysmal Atrial Fibrillation

Objectives: The aim of this study was to determine the mechanisms and effectiveness of pulmonary antrum radial-linear (PAR) ablation in comparison with pulmonary vein isolation (PVI) in patients with paroxysmal atrial fibrillation (AF) after a long-term follow-up. Background: The one-year follow up data suggested that PAR ablation appeared to have a better outcome over the conventional PVI for paroxysmal AF. Methods: The enrollment occurred between March, 2011, and August, 2011, with the last follow-up in May, 2014. A total of 133 patients with documented paroxysmal AF were enrolled from 5 centers and randomized to PAR group or PVI group. Event ECG recorder and Holter monitoring were conductedduring the follow-up for all patients. Results: The average procedure time was 151±23 min in PAR group and 178±43 min in PVI group ( P &lt;0.001). The average fluoroscopy time was 21±7 min in PAR group and 27±11 min in PVI group ( P= 0.002). AF triggering foci were eliminated in 59 patients (89.4%) in PAR group, whereas, only 4 patients (6.0%) in PVI group (P&lt;0.001).At median 36 (37-35) months of follow-up after single ablation procedure, 43 of 66 patients in PAR group (65%) and 28 of 67 patients in PVI group (42%) had no recurrence of AF off antiarrhythmic drug (AAD) (P=0.007); and 47 of 66 patients in PAR group (71%) and 32 of 67 patients in PVI group (48%) had no recurrence of AF with AAD (P=0.006). At the last follow-up, the burden of AF was significantly lower in PAR group than in PVI group (0.9% ± 2.3% vs 4.9% ± 9.9%;90th percentile, 5.5% vs 19.6%; P=0.008). No major adverse event (death, stroke, PV stenosis) was observed in all the patients except one case of pericardial tamponade. Conclusions: PAR ablation is a simple, safe, and effective strategy for the treatment of paroxysmal AF with better long-term outcome than PVI. PAR ablation might exhibit the beneficial effect on AF management through multiple mechanisms. Registration: ChiCTR-TRC-11001191

Abstract 15504: Time Course of Improvement of Diastolic Cardiac Function After Pulmonary Vein Isolation

Background: Pulmonary vein isolation (PVI) is an established method of paroxysmal atrial fibrillation (PAF). It has been reported that maintenance of sinus rhythm improves diastolic cardiac function in the patients with normal ejection fraction (EF). However, it is unknown the time course of improvement of diastolic cardiac function after PVI. Methods: We enrolled 87 patients who underwent PVI for PAF and received echocardiography before and 6-month/12-month after PVI. We evaluated left ventricular diastolic dimension, EF, left atrial dimension, EF, mitral early diastolic flow velocity (E), late diastolic flow velocity (A), ratio of early diastolic transmitral flow velocity to mitral annular velocity (E/e’), deceleration time (DcT) by the echocardiography and compared the ratio of pre to 6-mounth after PVI and of 6-mounth to 12-mounth after PVI for each parameter between success group (sinus rhythm≧1year) and recurrence group. Results: E/e’ ratio decreased at 6-months after PVI in success group (62patients) than recurrence group (25patients) (0.4334±0.3584% versus 0.0369±0.1169%, p=0.01) (table) but there were no significant differences in the other analyses. In addition there were no significant differences among 6-mounth to 12-mounth parameter. Conclusion: Diastolic cardiac function, especially E/e’, can improve in the early phase (within 6 months) if the patients maintained sinus rhythm after PVI.Early follow-up of diastolic function may play an important role to find recurrence of AF.

Dissociated pulmonary vein activity after pulmonary vein isolation for paroxysmal atrial fibrillation: a predictor for recurrence?

The role of dissociated pulmonary vein (DPV) activity after pulmonary vein isolation (PVI) is still poorly defined. We evaluated electrophysiological features and clinical impact on long-term outcome of DPV activity. A total of 243 patients (mean age 63 ± 11 years; 63% males) undergoing PVI for paroxysmal atrial fibrillation (AF) were included. DPV activity was defined as a residual low frequency irregular PV rhythm. Patients were divided into Group 1 (presence of DPV activity; n = 65) or Group 2 (absence of DPV activity; n = 178). Of 936 isolated PVs, 112 PVs (12%) showed DPV activity. DPV activity was observed more frequently in PVs identified as AF triggers (P = 0.026). During follow-up (mean 12 ± 7 months), 15 of 65 patients of Group 1 (23%) and 57 of 178 patients of Group 2 (32%) had an arrhythmia recurrence (P = 0.23). At linear regression analysis, no independent predictor for clinical recurrence was identified. During the repeat ablation, 62 of 72 patients (86%) showed a recovered PV conduction without difference between the 2 groups. Clinically, all patients of Group 1 with PV reconnection (n = 13/15) had a recurrence of paroxysmal AF. In Group 2, 5 of 52 patients with reconnected PV developed non-PV related arrhythmias. DPV activity occurred in 12% of PVs after PVI and was observed more frequently in PVs identified as AF triggers. DPV activity was not predictive for AF recurrence during follow-up. PV-left atrium reconnection involving PVs with DPV activity leads to AF.

A decade of complex fractionated electrograms catheter-based ablation for atrial fibrillation: Literature analysis, meta-analysis and systematic review

BackgroundIt has been a decade since the complex fractionated atrial electrograms (CFAEs) were first established following the publication of Nademanee's standards. However, the status and focus of CFAE research are unclear, as is the efficacy of additional CFAE ablation in atrial fibrillation (AF). This literature review and meta-analysis were designed to determine the status of CFAE research and the efficacy and complications of CFAE ablation alone, pulmonary vein isolation (PVI) alone and PVI plus CFAE ablation in AF. MethodsWith the assistance from reference librarians and investigators trained in systematic review, we conducted a literature search of MEDLINE (via PubMed), Embase, the Cochrane Library, ScienceDirect, Wiley Blackwell and Web of Knowledge, using “complex fractionated atrial electrograms” for MeSH and keyword search. ResultsThe literature on CFAEs increased from 2007, mainly focusing on mapping studies, with mechanism studies increasing significantly from 2012. Fifteen trials with 1525 patients were qualified for our meta-analysis. Success rates were as follows. Overall (P < 0.001): CFAE ablation alone, 23.5–26.2%; PVI, 64.7%; PVI plus CFAE ablation, 67.0%. Single ablation: PVI, 60.4%; PVI plus CFAEs, 68.8% (OR 1.53, 95% CI 1.07–2.20, P = 0.02). Re-ablation: PVI, 69.0%; PVI plus CFAEs, 77.2% (OR 1.54, 95% CI 1.06–2.24, P = 0.02). Paroxysmal AF: PVI, 76.7%; PVI plus CFAEs, 79.1% (OR 1.20, 95% CI 0.79–1.81, P = 0.39). Persistent or permanent AF: PVI, 47.9%; PVI plus CFAEs, 58.7% (OR = 1.59, 95% CI 1.13–2.24, P = 0.008). Complication rates: PVI, 2.6%; PVI plus CFAEs, 3.4% (OR 1.22, 95% CI 0.58–2.57, P = 0.61). ConclusionsIn the literature, CFAE mapping studies preceded mechanism studies. CFAE ablation alone is insufficient for the treatment of AF. Additional CFAE ablation after adequate PVI or PVI plus linear ablation improves the outcome of single ablation and re-ablation without increasing complications, especially in persistent or permanent AF. There are insufficient data to support a similar improvement in paroxysmal AF or inducible AF after PVI for paroxysmal AF.

Pulmonary antrum radial-linear ablation for paroxysmal atrial fibrillation: interim analysis of a multicenter trial

Background: Substrate abnormality in pulmonary vein (PV) antrum plays a critical role in mechanism of atrial fibrillation (AF). The present study compares the strategy of PV antrum radial-linear (PAR) ablation to encircling PV isolation for paroxysmal AF. Methods and results: A total of 86 patients with paroxysmal AF were randomly assigned to PAR ablation group or PV isolation group. The average procedure time was 161±21 min in PAR ablation group and 199±39 min in PV isolation group (P<0.01). The average fluoroscopy time was 25±5 min in PAR ablation group and 32±9 min in PV isolation group (P<0.001). At 14 (15-12) months of follow-up after single procedure, 31 of 42 (74%) patients in PAR ablation group and 22 of 44 patients (50%) in PV isolation group had no recurrence of AF off antiarrhythmic drug (AAD) (P=0.0249); and 36 of 42 patients (86%) in PAR ablation group and 26 of 44 patients (59%) in PV isolation group had no recurrence of AF with AAD (P=0.006). In addition, PAR ablation resulted in greater reduction of LA diameter than encircling PV isolation. Multivariable Cox regression analysis showed that only ablation strategy was independently associated with AF recurrence (HR, 0.31; 95% CI: 0.12-0.78; P=0.013). No major adverse event related to the procedures occurred. ![Figure][1] ablation patern in CARTO mapping Conclusion: This study suggests that PAR ablation is a potentially effective strategy for treatment of paroxysmal AF warranting further investigation. [1]: pending:yes

Pulmonary Antrum Radial–Linear Ablation for Paroxysmal Atrial Fibrillation

Background— Substrate abnormality in pulmonary vein (PV) antrum plays a critical role in mechanism of atrial fibrillation (AF). The present study compares the strategy of PV antrum radial–linear (PAR) ablation to encircling PV isolation for paroxysmal AF. Methods and Results— A total of 86 patients with paroxysmal AF were randomly assigned to PAR ablation group or PV isolation group. The average procedure time was 161±21 minutes in PAR ablation group and 199±39 minutes in PV isolation group ( P &lt;0.01). The average fluoroscopy time was 25±5 minutes in PAR ablation group and 32±9 minutes in PV isolation group ( P &lt;0.001). At 14 (15–12) months of follow-up after single procedure, 31 of 42 (74%) patients in PAR ablation group and 22 of 44 patients (50%) in PV isolation group had no recurrence of AF off antiarrhythmic drug ( P =0.0249); and 36 of 42 patients (86%) in PAR ablation group and 26 of 44 patients (59%) in PV isolation group had no recurrence of AF with antiarrhythmic drug ( P =0.006). In addition, PAR ablation resulted in greater reduction of left atrial diameter than encircling PV isolation. Multivariable Cox regression analysis showed that only ablation strategy was independently associated with AF recurrence (hazard ratio, 0.31; 95% confidence interval, 0.12–0.78; P =0.013). No major adverse event related to the procedures occurred. Conclusions— This study suggests that PAR ablation is a potentially effective strategy for treatment of paroxysmal AF warranting further investigation. Clinical Trial Registration— URL: http://www.chictr.org ; Unique identifier: ChiCTR-TRC-11001191.

Freedom from paroxysmal atrial fibrillation after successful pulmonary vein isolation with pulmonary vein ablation catheter-phased radiofrequency energy: 2-year follow-up and predictors of failure

In patients with paroxysmal atrial fibrillation (PAF) the pattern of atrial fibrillation (AF) episodes and the total AF burden, may be related to the efficacy of pulmonary vein isolation (PVI). We evaluated (pre)-procedural factors explaining the long-term outcome after PVI, using a ring-shaped multielectrode ablation catheter [pulmonary vein ablation catheter (PVAC)]. A total of 120 consecutive patients with PAF were treated with the PVAC. The patients' histories were obtained by a questionnaire and the clinical charts. Follow-up was performed at 3, 6, 12, 18, and 24 months with serial electrocardiogram, and multiple day Holter at 6, 12, and 24 months, as well as event recording in case of unexplained palpitations. At 1 year, 66 of 120 (55%, 95% confidence interval (CI) [46-63%]) patients were free of any left atrial (LA) arrhythmia without class I or III anti-arrhythmics after a single procedure. At 2 years, freedom from LA arrhythmia slightly declined further to 58 of 119 (49%, 95% CI [40-58%]). The only pre-procedural predictor of long-term success was a shorter duration of the longest episode of AF (hazard ratio (HR) 0.77 95% CI [0.64-0.92]). The only procedural predictor of long-term success was no need for direct current cardioversion (DCCV) for AF (HR 0.36 95% CI [0.21-0.61]). Since other characteristics in these PAF patients were very homogeneous, no further clinical predictors were observed. Freedom from LA arrhythmia after PVI for PAF with PVAC is 49% after 2-year follow-up, with little decline between year 1 and 2. Predictors of long-term failure were a longer duration of the longest episode of AF in the pre-procedural questionnaire, and a procedural DCCV for AF.

Pulmonary vein isolation with radiofrequency ablation followed by cryotherapy: a novel strategy to improve clinical outcomes following catheter ablation of paroxysmal atrial fibrillation

Pulmonary vein (PV) isolation for atrial fibrillation (AF) often requires repeat procedures due to PV reconnection. We hypothesized that wide area cicumferential ablation using radiofrequency energy (RFA) followed by ostial PV ablation with a cryoablation balloon would reduce the rate of AF recurrence compared with either approach alone. A retrospective study compared outcomes in the first 25 consecutive patients undergoing PV isolation for paroxysmal AF using the combined approach, to consecutive controls using either approach alone. Demographic and procedural data were collected from a prospective database. Kaplan-Meier curves were used to analyse AF free survival and curves were compared using the log-rank test. Twenty-five patients were included in each group. There were no major complications. Minor complications included two transient phrenic nerve palsies and a haematoma in both the combined groups and the cryoablation alone groups. In the RFA group the only complication was a grounding plate burn. Follow-up was 2.2 years in the RFA group, 1.0 years in the cryoablation group, and 1.4 years in the combined group. All recurrences but one occurred within one year. Freedom from AF was significantly greater in the combined group (80%) compared with the RFA alone group (52%) and the cryoablation alone group (56%, both P < 0.05). The combined approach was safe and increased single procedure efficacy of PV isolation for AF compared with either technique alone.

Noninvasive vectorcardiographic evaluation of pulmonary vein–atrial reconnection after pulmonary vein isolation for atrial fibrillation

Although pulmonary vein (PV)-left atrium (LA) reconnection is associated with recurrence of atrial fibrillation (AF) in patients who undergo pulmonary vein isolation (PVI), no noninvasive method for evaluating PV reconnection has yet been established. The purpose of this study was to examine whether PV-LA reconnection could be detected noninvasively by analyzing the change of P-loop configuration by vectorcardiography (VCG). The study included 80 patients with paroxysmal AF (8 female; mean age 58 ± 10 years) who underwent PVI. VCG was prospectively analyzed by recording during the procedure (before and after PVI) and 1 year after the procedure to noninvasively evaluate PV-LA reconnection. All patients showed a significant antero-leftward shift in the middle portion of the P loop on the horizontal plane of VCG, with an increase of the area within the P loop after the initial PVI (2.4 ± 1.7 vs 4.6 ± 2.7 × 10(3) mV(2), P <.001). Sixty-three (78.8%) patients without AF recurrence demonstrated no remarkable change in the P-loop area after 16 ± 11 months of follow-up (4.4 ± 2.7 vs 4.1 ± 2.5 × 10(3) mV(2), P = .51), whereas 17 (21.2%) patients with AF recurrence demonstrated P-loop reversion to the preprocedural P-loop morphology, with a decrease of P-loop area (5.6 ± 2.7 vs 3.2 ± 1.7 × 10(3) mV(2), P <.001). Change of the P loop on VCG was associated with subsequent PV-LA reconnection. VCG is helpful as a noninvasive method for detecting PV-LA reconnection after PVI for paroxysmal AF.