Pulmonary Vein Antrum Research Articles

Invasive strategies for rhythm control of atrial fibrillation: a narrative review.

Atrial fibrillation (AF) is the most common sustained tachyarrhythmia and its increasing prevalence has resulted in a growing healthcare burden. A recent landmark randomized trial, the EAST-AFNET 4 (Early Treatment of Atrial Fibrillation for Stroke Prevention Trial), highlighted the importance of early rhythm control in AF, which was previously underemphasized. Rhythm control therapy includes antiarrhythmic drugs, direct-current cardioversion, and catheter ablation. Currently, catheter ablation is indicated for patients with AF who are either refractory or intolerant to antiarrhythmic drugs or who exhibit decreased left ventricular systolic function. Catheter ablation can be categorized according to the energy source used, including radiofrequency ablation (RFA), cryoablation, laser ablation, and the recently emerging pulsed field ablation (PFA). Catheter ablation techniques can also be divided into the point-by-point ablation method, which ablates the pulmonary vein (PV) antrum one point at a time, and the single-shot technique, which uses a spherical catheter to ablate the PV antrum in a single application. PFA is known to be applicable to both point-by-point and single-shot techniques and is expected to be promising owing to its tissue specificity, resulting in less collateral damage than catheter ablation involving thermal energy, such as RFA and cryoablation. In this review, we aimed to outline catheter ablation for rhythm control in AF by reviewing previous studies.

Comparison of characteristics and acute ablation outcome of atrial fibrillation drivers detected using octaray vs. pentaray catheter

Abstract Background Atrial fibrillation (AF) driver ablation is proposed as treatment strategy beyond pulmonary vein (PV) isolation in persistent AF patients. The CARTOFINDER mapping system (Biosense Webster Inc.) can depict two types of activation patterns, focal and rotational activation, using unipolar potentials during AF. Recently, an 8-spline 48-electrodes mapping catheter (OctaRay) was developed. Purpose To evaluate the characteristics of AF drivers detected by CARTOFINDER using the OctaRay catheter and the acute termination compared to previous mapping catheter (PentaRay). Methods This is a multicenter prospective observational study from 6 hospitals where 47 persistent AF patients underwent initial catheter ablation from April to December 2023. We assessed the frequency and distribution of AF drivers in both atrium identified by CARTOFINDER using the OctaRay catheter before procedure. After PV isolation, additional ablation was performed on high-repetitive activations (focal activation>22 repetitions, rotational activation>17 repetitions) and the rate of acute AF termination was evaluated. Acute AF termination was defined as transition to sinus rhythm or atrial tachycardia (AT). The results were compared to 29 patients in whom the PentaRay catheter was used from September 2022 to March 2023. Results The mean age of OctaRay group was 72.0±8.6 years. The median AF duration was 0.7 years, and the prevalence of long-standing AF was 26%. All clinical characteristics was not significantly different between OctaRay and PentaRay group. Focal activation was more frequently identified in OctaRay group than in PentaRay group (94.1points/patient vs. 36.3points/patient, P<0.01), especially in anterior (P<0.01) and posterior (P<0.01) of right atrium (RA), posterior (P<0.01), roof (P<0.01) and lateral (P<0.01) of left atrium (LA), and PV antrum (P<0.01), respectively. Rotational activation was also more frequently identified in OctaRay group (54.7points/patient vs. 2.6points/patient, P<0.01), especially in anterior (P=0.02) and posterior (P=0.03) of RA, and anterior of LA (P=0.02), respectively. Furthermore, high-repetitive focal activation was more frequently identified in OctaRay group than in PentaRay group (P<0.01). On the other hand, the frequency of high-repetitive rotational activation was not significantly different between the two groups (P=0.63) (Figure A). In OctaRay group, high-repetitive focal activation was frequent in anterior of RA (72.3%) and LA appendage (48.9%) (Figure B), and had significantly shorter AF cycle length compared to the entire atrium (156ms vs. 162ms, P<0.01). Ablation for high-repetitive activations after PV isolation resulted in 12.8% acute AF termination in OctaRay group, significantly higher than in PentaRay group (vs. 0%, P=0.04). Conclusion The OctaRay catheter have the potential to detect more frequent and accurate AF drivers than the PentaRay catheter, leading to the improvement of acute AF termination.

Relationship between left atrial isolated surface area and early-term recurrence in patients with persistent atrial fibrillation after cryoballoon ablation

ObjectiveTo investigate the effect of pulmonary vein antrum enlargement combined with left atrial roof cryoballoon ablation in patients with persistent atrial fibrillation (PeAF) by analyzing the relationship between left atrial isolation area surface area (ISA) and early postoperative recurrence.Methods93 patients with PeAF were classified into recurrence and non-recurrence groups according to the results of the 1-year follow-up. Three-dimensional electroanatomical labeling map was constructed and merged with that of the left atrial pulmonary vein CTA, and the ISA and the left atrial surface area (LASA) were measured and analyzed to determine the relationship between ISA/LASA in relation to early postoperative recurrence.Results93 patients were included and followed up for 1 year with AF-free recurrence rate of 75.3%. The ISA of the recurrence group was lower than that of the non-recurrence group. Left atrial internal diameter (LAD), left common pulmonary vein, the ISA, the ISA/LASA and early-term recurrence had statistical significance in both groups. The factors that significantly predicted early-term recurrence were left common pulmonary vein and the ISA/LASA. ISA/LASA (HR 0, 95% CI 0–0.005, P = 0.008) and left common pulmonary vein trunk (HR 7.754, 95% CI 2.256–25.651, P = 0.001) were the independent risk factors for early recurrence. ROC curve analysis showed that ISA/LASA predicted the best early recurrence after operation with a cut-off value of 15.2%.ConclusionA greater ISA/LASA reduces early recurrence after cryoablation in patients with PeAF. An ISA/LASA of 15.2% may be the best cut-off value for predicting early recurrence after cryoablation for PeAF.

Understanding electrical pulmonary vein antrum for paroxysmal atrial fibrillation: Further look into superhigh-density electroanatomic mapping of the left atrium

BackgroundAn isolation line placed at the pulmonary vein antrum (PVA) area is superior to ostium level in atrial fibrillation (AF) control. However, less is known about the electrophysiologic characteristics of the PVA. ObjectiveThe aim of this study was to describe the electrophysiologic properties of the PVA. MethodsHigh-density mapping of the left atrium was performed in 18 paroxysmal AF (PAF) patients and 9 age- and sex-matched paroxysmal supraventricular tachycardia (PSVT) patients. Each PVA was divided into 8 segments, and the pulmonary vein (PV) was divided into 4 segments. The electrophysiologic properties included slow conduction, complex fractionated electrograms, and effective refractory period (ERP). ResultsSlow conduction was more prevalent at the PVA (43.2% ± 19.5% vs 14.7% ± 13.0%; P = .001) and PV (61.9% ± 16.4% vs 9.1% ± 9.0%; P < .001) in PAF patients than in PSVT patients during sinus rhythm. Similarly, the area with complex fractionated electrograms was significantly larger at the PVA (133.8 [61.6–233.2] mm2 vs 0.0 [0.0–41.4] mm2; P = .011) in PAF patients during sinus rhythm. The ERP of the PVA was longer in PAF patients than in control at the drive length of 600 ms (260 [230–280] ms vs 220 [190–250] ms; P = .001) and 400 ms (230 [205–250] ms vs 200 [190–220] ms; P = .007). The ERP net difference between the PV and PVA is larger in PAF patients than in control both at 600-ms pacing (40 [20–70] ms vs 10 [10–30] ms; P < .001) and at 400-ms pacing (40 [20–60] ms vs 20 [10–30] ms; P < .001). ConclusionPAF patients have the PVA electrical substrate including slow conduction, complex fractionated electrograms, and ERP dispersion.

Catheter ablation approach targeting epicardial connections to the right pulmonary vein antrum detected before pulmonary vein isolation

BackgroundEpicardial connections from surrounding structures to the right pulmonary vein (PV) antrum impede PV isolation. ObjectiveThis study aimed to evaluate the efficacy of an ablation approach targeting epicardial connections for right PV isolation. MethodsWe prospectively enrolled 124 patients with atrial fibrillation undergoing initial PV isolation. We identified the activation breakthrough into the right PV antrum (BT-RPV) on the activation map created during high right atrial pacing before PV isolation. BT-RPV sites were targeted when right PV isolation was not achieved by wide antral circumferential ablation (WACA). ResultsBT-RPV was observed in 83 patients (67%). PV isolation was achieved by WACA in all 41 patients without BT-RPV. Among patients with BT-RPV, PV isolation was achieved by WACA in 48 patients when all BT-RPV sites were covered by the PV isolation line. Conversely, PV isolation was completed by WACA in only 5 of 35 patients when not all BT-RPV sites were covered. In patients where WACA failed, 35 sites were targeted for BT-RPV ablation. Initial BT-RPV ablation led to PV isolation at 20 sites, while the remaining 15 BT-RPV sites required repeat BT-RPV ablation. The ablated area of successful BT-RPV ablation was 0.9 (0.6–1.2) cm2, corresponding to the area activated within 15 (14–16) ms after BT-RPV emergence. Ablating the area activated within 14 ms of BT-RPV emergence was associated with successful PV isolation (sensitivity 91%; specificity 100%). ConclusionAblation targeting BT-RPV sites is effective for right PV isolation. Extensive ablation is required to eliminate BT-RPV.

Difference between cryoballoon and radiofrequency ablations for atrial fibrillation based on electroanatomical mechanisms

Abstract Backgrounds Cryoballoon pulmonary vein isolation (PVI; Cryo-PVI) has comparable results to conventional radiofrequency PVI (RF-PVI) in patients with atrial fibrillation (AF). However, Cryo-PVI using a 28-mm cryoballoon has limitations for wide circumferential PVI or extra-pulmonary vein (PV) trigger (ExPVT) ablations. We compared long-term outcomes of Cryo-PVI and RF-PVI in patients without ExPVT and explored the potential electroanatomical mechanisms. Methods We identified 2,160 patients who underwent de novo AF ablation. After propensity score matching for age, sex, AF type, and left atrial (LA) diameter for patients without ExPVT (female 24.6%, mean 61.8years old, paroxysmal AF 53.2%), we compared rhythm outcomes between 403 Cryo-PVI and 403 RF-PVI procedures, considering AF type and LA size. We determined the LA diameter cutoff which best differentiated rhythm outcomes between RF-PVI and Cryo-PVI using a maximum likelihood approach based on the Cox proportional hazard model and investigated the relationship between PVI level and LA mass reduction through computational modeling. Results During the 24 months of median follow-up, Cryo-PVI showed poorer rhythm outcomes to RF-PVI (Log-rank p=0.009) in overall patients. However, Cryo-PVI showed comparable overall rhythm outcomes to RF-PVI (Log-rank p=0.370) in patients with paroxysmal AF. Cryo-PVI showed higher AF recurrence in patients with larger LA size (LA diameter≥40mm; hazard ratio [HR] 1.55 [1.04-2.30]; log-rank p=0.030) or with persistent AF (log-rank p=0.001). In the computational modeling, PV antrum was likely to be covered by Cryo-PVI in patients with small LA, but not in those with large LA. Conclusions Cryo-PVI showed inferior rhythm outcomes than RF-PVI in patients with higher LA diameter or with persistent AF.

Role of high-density voltage map guiding parosysmal atrial fibrillation ablation

Abstract Background High-density mapping of the pulmonary vein antra has been demonstrated to improve the detection of conduction gaps in wide antral catheter ablation (WACA) approach for the treatment of paroxysmal atrial fibrillation (AF). Purpose We aimed to compare the AF recurrencies in patients treated with WACA for pulmonary veins isolation (PVI) guided by high-density bipolar voltage map (BVM) vs WACA guided by a standard 20-pole circumferential mapping catheter (CMC-20). Methods This prospective study included patients scheduled for AF ablation in a single center. In group A (85 patients) PVI was achieved with a conventional approach using CMC-20; in group B (96 patients) high density BVM was acquired by sequential multielectrode mapping through Pentaray Catheter (Biosense Webster). More than 1000 voltage points per map were acquired. Acute PVI was defined as an entrance and exit block after ≥ 20 min waiting period. In both groups WACA was perfomed using a contact force sensing catheter targeting an interlesion distance ≤6 mm and ablation index ≥400 at posterior wall and ≥550 at anterior wall. The primary endpoint was the AF recurrencies in the two groups. Results A total of 181 patients were included (mean age 64.9±10.6 years, 33.1% female): in 85 patients AF ablation was guided by CMC-20, in 96 patients AF ablation was guided by BVM; WACA PVI was achieved in all patients. There were no significant differences in the clinical characteristics of the two groups (table 1). At 12-month follow-up, AF recurrencies were significantly lower in the BVM group compared with CMC-20 group [11/96 (11.4%) vs 19/85 (22.3%) respectively, p=0.01]. Conclusions High-density BVM might increase success rate of AF ablation compared with a conventional 20-pole circumferential mapping approach.

The efficacy and safety of additional pulmonary vein antrum substrate ablation after cryo-ablation in patients with persistent atrial fibrillation

Abstract Background Cryo-ablation for persistent atrial fibrillation (PeAF) has been reported to be safe and comparable to radiofrequency (RF) ablation, but the outcome was not satisfactory. AF drivers mapping after pulmonary vein isolation (PVI) was reported to be widely identified in left atrium (LA). On the other hand, extensive drivers ablation is considered to have limited durability of PVI compared to cryo-ablation. Purpose This study sought to investigate the efficacy and safety of additional PV antrum substrate ablation after PVI by cryo-ablation in patients with PeAF. Methods A total of 122 consecutive patients (90 men, 32 women) who underwent ablation between January 2021 and July 2023 for PeAF, except for patients with long standing ≥10years AF, or large LA diameter ≥55mm, or low left ventricular ejection fraction (LVEF) ≤35% with organic heart disease, were divided into three groups; cryo-ablation alone (Cryo group; 30 patients), RF ablation alone guided by AF drivers mapping (RF group; 52 patients), or cryo-ablation plus RF for AF drivers (Cryo+RF group; 40 patients). AF drivers mapping was performed by real-time phase mapping system or complex fractionated electrograms (Figure1). The outcome of freedom from atrial tachy-arrhythmia lasting longer than 30 seconds without anti-arrhythmic drugs after three months blanking period of a single procedure was compared among groups. Results Baseline characteristics of patients (68±9.2 years old, LVEF 57±9.9 %, LA diameter 43±5.4 mm, persistent AF duration 9.4±18 months, long standing ≥1year AF 17 patients) were similar in three groups. The incident of recurrence of atrial tachy-arrhythmia in Cryo+RF group was significantly lower compared with Cryo group (15% vs. 37%; p=0.014) and RF group (15% vs. 25%; p=0.28) (Figure2). There was no serious complication in three groups. Conclusion Additional drivers RF ablation after cryo-ablation for PeAF is safe and associated with a significant reduction in atrial tachy-arrhythmia recurrence.Figure 1Figure 2

One-year outcome of wide-area pulmonary vein isolation using the third-generation visually guided laser balloon

Abstract Background The third-generation laser balloon (LB3) is equipped with an ultra-compliant balloon and a motor-driven laser generator, which contribute to durable and gapless isolated lesion creation. However, the efficacy of wide-area pulmonary vein (PV) isolation (PVI) using LB3 remains to be elucidated. Purpose This study aims to investigate efficacy of wide-area PVI using LB3. Methods This is a single-center retrospective study. Patients with atrial fibrillation (AF) who underwent LB3 ablation during the period from August 2021 to June 2022 were enrolled. All PVs were electrically isolated only by LB3. After initial circular ablation, LB3 was inflated to a larger size at each PV, and the isolation area was extended. After ablation, voltage maps of the left atrium were obtained by high-resolution mapping catheters to evaluate isolation areas (&amp;lt;0.1mV). Follow-up included a 12-lead electrocardiogram, Holter monitoring, and/or pacemaker/implantable cardioverter-defibrillator interrogation. The efficacy endpoint was defined as freedom from atrial tachyarrhythmia (ATa) between months 3 and 12. Results Forty-four patients with paroxysmal AF and 34 with persistent AF (mean arrhythmia duration 12.4 months, range 1–60 months) were included. First pass isolation was achieved in 90.6% (280/309) of PVs. The total laser application time was 24.1±6.4 minutes, and the total delivered energy was 15.3±3.2 kJ. The isolation area at the left- and right-sided PV antrum were 14.2±1.8 and 19.5±1.1 cm², respectively. At the end of the 12 months of follow-up, the freedom from ATa was 78.2% in patients with paroxysmal AF and 78.0% in persistent AF, which indicates ATa free survival at one year was similar in both groups (P=0.91). Conclusions Wide-area PVI using LB3 may lead to favorable outcomes in patients with AF.Fluoroscopic and endoscopic imageKaplan-Meier curves and voltage map

The impact of additional radiofrequency ablation for atrial fibrillation substrates using with ExTRa-Mapping analysis after Cryo-ablation in patients with persistent atrial fibrillation

Abstract Background Pulmonary vein isolation (PVI) for persistent atrial fibrillation (AF) is well established. Cryo-ablation for persistent AF has been reported to be safe and effective and comparable to radiofrequency (RF) ablation in long term arrhythmia-free survival, but the outcome is limited. Phase mapping using software of ExTRa-Mapping is a new tool to clarify the real-time imaging of the AF wave dynamics. Purpose We investigated the distribution of rotors of left atrium (LA) after PVI by Cryo-ablation, and the efficacy and safety of additional RF ablation for AF substrates (rotor modification) after Cryo-ablation. Methods A total of 50 patients who underwent persistent AF ablation in our hospital were enrolled. The Cryo-ablation alone group (Cryo group; n=25) and the Cryo-ablation + additional RF substrates ablation group (Cryo+RF group; n=25) were randomly divided. First, PVI with Cryo-ablation was performed. Second, if AF did not term after PVI, the rotor of LA were analyzed using the NAVX and ExTRa-Mapping system. In Cryo+RF group, the extensive RF ablation of the PV antrum to modify the rotor area were performed (Abstract Picture 1). The recurrence rate of any atrial tachy-arrhythmia without anti-arrhythmic drugs and safety were evaluated in both groups. Results The patient characteristics (69 ± 9.2 years old, body-mass index 24 ± 3.2 kg/m2, LA diameter 43 ± 5.1 mm, left ventricular ejection fraction 60 ± 7.8 %, persistent AF duration 4.2 ± 5.1 months) did not differ between the both groups. The distribution of rotors of LA were predominantly present in the anterior (n = 36) and inferior (n = 27) walls of the LA, with only a few in the posterior wall (n = 7) in the both groups. In Cryo+RF group, except for 4 cases in which AF was termed by PVI or a rotor was not detected, extensive RF modification in anterior antrum of right pulmonary vein was performed in 18 of 21 cases. In an average follow-up of 482 ± 273 days, the recurrence rate of any atrial tachy-arrhythmia was significantly lower in Cryo+RF group compared with Cryo group (p=0.029, Abstract Picture 2). No serious complications occurred in both groups. Conclusion Additional extensive RF ablation of the PV antrum to modify the Rotor area resulted in a lower recurrence rate in patients with persistent AF.Modify the rotor areaRecurrence rate

Quantifying pulmonary vein antrum contact area with novel dual-sized cryoballoon to optimize pulmonary vein isolation

Quantifying pulmonary vein antrum contact area with novel dual-sized cryoballoon to optimize pulmonary vein isolation

Identification of epicardial connections can improve the success rate of first-pass right pulmonary vein isolation

BackgroundEpicardial connections between the right pulmonary vein (PV) and the right atrium have been reported. ObjectiveWe evaluated the usefulness of our new PV isolation (PVI) strategy with identification of these epicardial connections. MethodsOverall, 235 patients with atrial fibrillation were included. High-density mapping of the left atrium was performed to identify the earliest activation sites (EASs) before PVI in all patients. With our new strategy, if we identified EASs around the right PV carina, we ablated these sites in addition to performing usual first-pass circumferential PVI. The patients were divided into two groups according to the ablation strategy. One hundred fifteen patients underwent first-pass PVI without information on EASs (non-analyzed group), and 78 patients underwent ablation at EASs around the right PV carina in addition to PVI (analyzed group). After first-pass ablation around the PV antrum, re-mapping was performed. ResultsHigh-density mapping before PVI showed that the prevalence of EASs around the right PV carina was 10.9% in all patients (9.6% in the non-analyzed group and 12.8% in the analyzed group; p = 0.74. The first-pass right PVI success rate was higher in the analyzed group than in the non-analyzed group (93.6% vs. 82.6%; p = 0.04). The radiofrequency application time for PVI was significantly shorter in the analyzed group than in the non-analyzed group (45.6 ± 1.0 min vs. 51.2 ± 0.9 min; p < 0.05). ConclusionIdentification of epicardial connections before ablation could improve the success rate of first-pass right PVI.

Quantitative comparison of the isolation lesions between conventional- and larger-sized visually guided laser balloon ablation.

The importance of a wider circumferential isolation of the pulmonary veins (PV), which includes a large portion of the left atrial posterior wall (LAPW), has been suggested in several studies. However, the extended isolation area using a larger inflated visually guided laser balloon (VGLB) ablation remains to be elucidated. Seventy-eight patients with atrial fibrillation (AF) who underwent VGLB ablation were enrolled in this prospective study. An electroanatomic map of the left atrium was obtained before and after PV isolation (PVI) using a conventional-sized VGLB. The isolation areas were extended by the largest-sized VGLB ablation and remapped in the same manner. After the ablation, isolation areas were calculated with CARTO-3 system.The one-year atrial arrhythmia (Ata) recurrence was assessed. RESULTS: The largest-sized VGLB ablation yielded statistically greater areas of isolation in left-sided PV antrum (PVA) (11.5 ± 2.3 cm2 vs. 15.9 ± 3.5 cm2, P < .001) and right-sided PVA (14.2 ± 3.3 cm2 vs. 20.6 ± 4.4 cm2, P < .001) than the conventional-sized VGLB. Further, non-ablated LAPW (12.3 ± 4.4 cm2 vs. 7.8 ± 3.9 cm2, P < .001) was significantly reduced after largest-sized VGLB ablation, compared to the conventional-sized VGLB ablation.The one-year Ata freedom was 83.7% in patients with paroxysmal AF and 96.4% in those with persistent AF. The largest-sized VGLB ablation technique can create a significantly wider isolation area of PVA and debulk a large amount of LAPW than the conventional-sized VGLB ablation.The one-year outcome was similarly high in paroxysmal and persistent AF.

One-year outcomes of wide antral cryoballoon ablation guided by high-density mapping vs. conventional cryoballoon ablation for atrial fibrillation: a propensity score-matched study.

Pulmonary vein isolation with wide antral ablation leads to better clinical outcomes for the treatment of atrial fibrillation, but the isolation lesion is invisible in conventional cryoballoon ablation. In this study, we aim to investigate the efficacy of the wide pulmonary vein isolation technique that includes the intervenous carina region, guided by high-density mapping, compared with pulmonary vein isolation alone without the mapping system. We conducted a propensity score-matched comparison of 74 patients who underwent a wide cryoballoon ablation guided by high-density mapping (mapping group) and 74 controls who underwent conventional cryoballoon ablation in the same period (no-mapping group). The primary outcome was a clinical recurrence of documented atrial arrhythmias for >30 s during the 1-year follow-up. Of 74 patients in the mapping group, residual local potential in the pulmonary vein antrum was found in 30 (40.5%) patients, and additional cryothermal applications were performed to achieve a wide pulmonary vein isolation. Compared with the no-mapping group, the use of the mapping system in the mapping group was associated with a longer fluoroscopic time (26.97 ± 8.07 min vs. 23.76 ± 8.36 min, P = 0.023) and greater fluoroscopic exposure [339 (IQR181-586) mGy vs. 224 (IQR133-409) mGy, P = 0.012]. However, no significant differences between the two groups were found in terms of procedural duration and left atrial dwell time (104.10 ± 18.76 min vs. 102.45 ± 21.01 min, P = 0.619; 83.52 ± 17.01 min vs. 79.59 ± 17.96 min, P = 0.177). The rate of 12-month freedom from clinical atrial arrhythmia recurrence was 85.1% in the mapping group and 70.3% in the no-mapping group (log-rank P = 0.029). Voltage and pulmonary vein potential mapping after cryoballoon pulmonary vein isolation can identify residual potential in the pulmonary vein antrum, and additional cryoablation guided by mapping leads to improved freedom from atrial arrhythmias compared with conventional pulmonary vein isolation without the mapping system. ChiCTR2200064383.

Insufficient Ablation is Associated with Atrial Fibrillation Recurrence after Combining Ablation and Left Atrial Appendage Closure.

The combination of left atrial appendage closure (LAAC) and catheter ablation (CA) in a single procedure is a safe and effective form of treatment for atrial fibrillation (AF). However, several findings have argued that LAAC might increase the risk of AF recurring. Therefore, this study investigated the impact of insufficient ablation on AF recurrence after the hybrid procedures of CA and LAAC. We reviewed 107 consecutive patients with AF who received the CA and LAAC hybrid procedures (combined group). In the case-control study, another 107 patients who underwent only CA (ablation group) were successfully matched using propensity score matching. After correcting the insufficient ablation, 107 consecutive patients were enrolled prospectively. During the follow-up period, postprocedural 24-hour monitor recordings and a portable electrocardiogram (ECG) monitoring device were used to detect AF recurrence. Transesophageal echocardiography was used to evaluate LAAC. The combined group showed an increase in the risk of AF recurrence after 539.2 304.4 days of follow-up (29.9% vs. 15.9%, p 0.05). Interestingly, the duration of the procedure was not significantly prolonged when LAAC was added after CA in the combined group, while there was a higher number of ablating attempts, duration of ablation, and additional ablation in the ablation group for both radiofrequency and cryoballoon ablation. After correcting for the insufficient ablation, the corrected group showed a significant decrease in AF recurrence after 420.4 204.8 days of follow-up. Insufficient ablation is common when combining CA and LAAC and may lead to the recurrence of atrial fibrillation. It should be corrected intentionally by sufficient ablation of the pulmonary vein antrum and additional ablation. The prospective study is a sub-study of our CAGEDAF study that has already been registered (ChiCTR2000039746).

Incidence of cryoballoon expansion dislodgement during pulmonary vein isolation-An underappreciated frequent cause of incomplete isolation.

Cryoballoon ablation for atrial fibrillation (AF) requires adequate contact between the pulmonary vein (PV) antrum and cryoballoon. The surge of intraballoon pressure during the initial phase of ablation may change the balloon's shape and compliance, resulting in balloon dislodgement and loss of PV occlusion. Without continuous monitoring, this phenomenon is often undetected but can be associated with incomplete PV isolation (PVI). Primary cryoablation of AF was performed in 15 patients. PV occlusion status pre- and post-freezing were analyzed with intracardiac echocardiography (ICE) and dielectric imaging-based occlusion tool (DIOT) to calculate the incidence of expansion dislodgement of cryoballoon. A total of 105 cryoablation applications were performed on 57 veins, including three common ostiums of left pulmonary veins. In the evaluation of PV occlusion, both modalities reported consistent results in 86.7% of the assessments. Despite complete PV occlusion before ablation, peri-balloon leak after initiation of freezing was detected by ICE in 5/22 (22.7%) applications and by DIOT in 8/25 (32%) applications. Incidence of expansion dislodgement of the cryoballoon was detected in one-fourth to one-third of cryoablation applications depending on the imaging modality used, which was clinically frequent and significant.

'Single-shot' pulmonary vein isolation using a novel lotos pulsed field ablation catheter: a pre-clinical evaluation of feasibility, safety, and 30-day efficacy.

Pulsed field ablation (PFA) is emerging as a non-thermal, tissue-specific technique for pulmonary vein isolation (PVI) in atrial fibrillation therapy. This pre-clinical study aims to investigate the feasibility and safety of PVI using a novel PFA system including a nanosecond-scale PFA generator, a novel lotos PFA catheter, and a customized 12 Fr steerable sheath. A total of 11 Yorkshire swine were included in this study, with 4 in the acute cohort and 7 in the chronic cohort. Under general anaesthesia, transseptal puncture and pulmonary vein (PV) angiography was initially performed. The PFA catheter was navigated to position at the right and left PV antrum after the electroanatomic reconstruction of the left atrium. Biphasic PFA applications were performed on PVs in both the spindle-shaped and the lotos-shaped poses. Pulmonary vein isolation and PFA-associated safety were assessed 30 min after ablation in both cohorts and 30 days later in the chronic cohort. Detailed necropsy and histopathology were performed. Additional intracardiac echocardiography and coronary angiogram were evaluated for safety. All target PVs (n = 20) were successfully isolated on the first attempt. No spasm of coronary artery or microbubble was seen during the procedure. Eleven of 12 PVs (91.6%) remained in isolation at the 30-day invasive study. No evidence of PV stenosis was observed in any targets. However, transient diaphragm capture occurred in 17.6%. Histopathological examinations showed no evidence of collateral injury. This study provides scientific evidence demonstrating the safety and efficacy of the novel PFA catheter and system for single-shot PVI, which shows great potential.

Cardiac magnetic resonance for early atrial lesion visualization post atrial fibrillation radiofrequency catheter ablation.

Incomplete atrial lesions resulting in pulmonary vein-left atrium reconnection after pulmonary vein antrum isolation (PVAI), are related to atrial fibrillation (AF) recurrence. Unfortunately, during the PVAI procedure, fluoroscopy and electroanatomic mapping cannot accurately determine the location and size of the ablation lesions in the atrial wall and this can result in incomplete PVAI lesions (PVAI-L) after radiofrequency catheter ablation (RFCA). We seek to evaluate whether cardiac magnetic resonance (CMR), immediately after RFCA of AF, can identify PVAI-L by characterizing the left atrial tissue. Ten patients (63.1 ± 5.7 years old, 80% male) receiving a RFCA for paroxysmal AF underwent a CMR before (<1 week) and after (<1 h) the PVAI. Two-dimensional dark-blood T2-weighted short tau inversion recovery (DB-STIR), Three-dimensional inversion-recovery prepared long inversion time (3D-TWILITE) and three-dimensional late gadolinium enhancement (3D-LGE) images were performed to visualize PVAI-L. The PVAI-L was visible in 10 patients (100%) using 3D-TWILITE and 3D-LGE. Conversely, On DB-STIR, the ablation core of the PAVI-L could not be identified because of a diffuse high signal of the atrial wall post-PVAI. Microvascular obstruction was identified in 7 (70%) patients using 3D-LGE. CMR can visualize PVAI-L immediately after the RFCA of AF even without the use of contrast agents. Future studies are needed to understand if the use of CMR for PVAI-L detection after RFCA can improve the results of ablation procedures.

Assessing left atrial intramyocardial fat infiltration from computerized tomography angiography in patients with atrial fibrillation.

Epicardial adipose tissue might promote atrial fibrillation (AF) in several ways, including infiltrating the underlying atrial myocardium. However, the role of this potential mechanism has been poorly investigated. The aim of this study is to evaluate the presence of left atrial (LA) infiltrated adipose tissue (inFAT) by analysing multi-detector computer tomography (MDCT)-derived three-dimensional (3D) fat infiltration maps and to compare the extent of LA inFAT between patients without AF history, with paroxysmal, and with persistent AF. Sixty consecutive patients with AF diagnosis (30 persistent and 30 paroxysmal) were enrolled and compared with 20 age-matched control; MDCT-derived images were post-processed to obtain 3D LA inFAT maps for all patients. Volume (mL) and mean signal intensities [(Hounsfield Units (HU)] of inFAT (HU -194; -5), dense inFAT (HU -194; -50), and fat-myocardial admixture (HU -50; -5) were automatically computed by the software. inFAT volume was significantly different across the three groups (P = 0.009), with post-hoc pairwise comparisons showing a significant increase in inFAT volume in persistent AF compared to controls (P = 0.006). Dense inFAT retained a significant difference also after correcting for body mass index (P = 0.028). In addition, more negative inFAT radiodensity values were found in AF patients. Regional distribution analysis showed a significantly higher regional distribution of LA inFAT at left and right superior pulmonary vein antra in AF patients. Persistent forms of AF are associated with greater degree of LA intramyocardial adipose infiltration, independently of body mass index. Compared to controls, AF patients present higher LA inFAT volume at left and right superior pulmonary vein antra.

The efficacy of ultra-high-density mapping guided partial antral ablation for pulmonary vein isolation in atrial fibrillation patients

BackgroundThe muscular discontinuities or lack of myocardial extensions around the pulmonary veins (PVs) antrum were previously reported. The objective of our study was to compare the efficacy of a partial antral ablation for PV isolation (PVI) using ultra-high density (UHD) mapping with a conventional wide antral circumferential ablation (WACA) in atrial fibrillation (AF) patients.MethodsA total of 119 patients medical records who received catheter ablation for AF in our hospital were analyzed. In one group of patients, detailed activation mapping of each PV was performed using a UHD mapping system. Each PV antral segment’s activation pattern was classified into “directly-activated from the LA” or “passively-activated from an adjacent PV segment” patterns. The ablation applications were performed at the directly-activated PV antral segment only for the PVI when the PV had “passively-activated segments” (partial antral ablation; PA-UHD group). Another patient group received a conventional WACA for the PVI (WACA group).ResultsSixty patients received partial antral ablation (PA-UHD), and age/sex-matched 59 patients received WACA. In the PA-UHD group, passively-activated segments were observed in 58.3% of all PV segments. The success rate of a partial antral ablation for the PVI in PVs with passively-activated segments was 85%. The 1-year atrial tachyarrhythmia recurrence did not differ between the PA-UHD and WACA groups.ConclusionsOur study revealed the presence of passively-activated PV segments, which could potentially indicate muscular discontinuity at the PV-LA junction. In most PVs with passively-activated segments, PVI was successfully achieved by ablation with only directly-activated segments. The 1-year recurrence rate of atrial tachyarrhythmia in PA-UHD group was comparable to that observed in the WACA group.