Antral Pulmonary Vein Isolation Research Articles

Low voltage-guided ablation of posterior wall improves 5-year arrhythmia-free survival in persistent atrial fibrillation.

The posterior wall (PW) has been proposed as a standard target for ablation beyond pulmonary vein antral isolation(PVI) in patients with persistent atrial fibrillation(AF). However, studies have shown inconsistent outcomes with the addition of PW ablation. The presence or absence of low voltage on the PW may explain these inconsistencies. We evaluated whether PW ablation based on the presence or absence of low voltage improves long-term arrhythmia-free outcomes. We retrospectively reviewed 5-year follow-up in 152 consecutive patients who received either standard ablation (SA) with PVI alone or PVI + PW ablation (PWA) based on physician discretion (n = 77) or voltage-guided ablation (VGA) with PVI and addition of PWA only if low voltage was present on the PW (n = 75). The two groups were well matched for baseline characteristics. At 5-year follow-up, 64% of patients receiving VGA were atrial tachyarrhythmia(AT)/AF free compared to 34% receiving SA (HR 0.358 p < .005). PWA had similar AF recurrence in SA and VGA groups (0.30 vs. 0.27 p = .96) but higher AT recurrence when comparing SA and VGA groups (0.39 vs. 0.15 p = .03). In multivariate analysis, both VGA and PWA predicted AF arrhythmia-free survival (HR 0.33, p = .001 and HR 0.20, p = .008, respectively). For AT, VGA predicted arrhythmia-free survival (HR 0.22, p = .028), while PWA predicted AT recurrence (HR 4.704, p = .0219). VGA of the posterior wall ablation beyond PVI in persistent AF significantly improves long-term arrhythmia-free survival when compared with non-voltage-guided ablation. PW ablation without voltage-guidance reduced AF recurrence but at the cost of a higher incidence of AT.

On a Possible Approach to Risk Prediction of Recurrence of Atrial Fibrillation аfter Catheter Ablation According to Data from the Pre-procedure Period

The aim of the study is to identify and evaluate predictors of recurrent paroxysms of atrial fibrillation (AF) paroxysms based on data from the preprocedural period among personal indices, history, comorbidities, ultrasound examination, and morphological components of f-waves, such as spectral amplitude and frequency. 39 patients with antral pulmonary vein isolation using radiofrequency or cryoenergy were included. Spectral analysis of f-waves was performed by fast Fourier transform of the ECG signal after suppression of the T-wave and QRS-complex. The performed U-test for the difference between the amplitude and frequency indicators in the groups without and with recurrence of AF shows a significant difference between the amplitude values in the two studied groups of patients. Through a stepwise discriminant analysis of a total of 14 indicators, 5 reliably separated groups without and with recurrence were determined: Echo LV-EF, spectral amplitude of f-waves, heart failure, Stroke/TIA, diabetes. The discriminator synthesized on these indicеs classified among the 39 patient – 25 without relapse (group 1) and 14 with relapse (group 2), 3 patients wrong from group 1 to group 2 (false positive), or 12%, and 1 patient was wrong from group 2 to group 1 (false negative), or 7.1%. These results give grounds to accept the hypothesis that it is possible to develop a decision rule for determining the degree of risk of post-procedural recurrence of AF from pre-procedural period data.

High power short duration (HPSD) versus lower power longer duration (LPLD) atrial fibrillation ablation: a multi-centre randomised controlled trial (HiLo-HEAT study)

Abstract Funding Acknowledgements Type of funding sources: None. Background Lower power (25W) longer duration (LPLD) radiofrequency (RF) ablation has conventionally been used on the posterior wall during pulmonary vein isolation (PVI) for atrial fibrillation (AF), to attenuate the risk of esophageal thermal injury (ETI). High power (40-50 W) short duration (HPSD) RF ablation results in shorter procedural times with no increase in ETI. However evidence had been limited by non-randomised studies. Purpose To compare HPSD versus LPLD ablation and the effects on esophageal thermal injury (ETI) and procedural outcomes. Methods In this multi-centre, prospective, randomised control trial, 88 patients with paroxysmal/persistent AF undergoing their first RF ablation procedure were randomised 1:1 to HPSD or LPLD ablation. Anterior wall ablation was done in both arms using 40-50 W, with ablation target of AI 500-500/ LSI 5-5.5. Posterior wall ablation was done using 40-50W (HPSD group) versus 25 W (LPLD group), with target AI 400/ LSI 4. Ablation involves wide antral circumferential PVI using contact force sensing ablation catheters, with additional ablation lines as per operator discretion. Circa multi-sensor esophageal temperature monitoring (ETM) probe was utilized. Endoscopy was performed within 24 hours to assess for ETI. The primary outcome was incidence of ETI, with secondary outcomes including acute procedural endpoints. Results Mean age of the cohort was 61+/-9 years, with 31% females. 36 (41%) had PAF. PVI was achieved in 100% of patients, with posterior wall isolation (PWI) added in 19 PsAF patients (21.6%). There were more hypertensive patients in HPSD (p = 0.02). Significant esophageal luminal temperature rises (≥ 38 c) were seen in 93.2% of patients, with no difference between groups (p = 0.69). First pass isolation rates for left and right PVs were 85% and 61% respectively, with similar rates in both groups (p = 0.37, p = 0.65 respectively). HPSD group had shorter RF time (1613 vs 2303 secs, p &amp;lt;0.04), and fluoroscopy times (11.4 vs 13.1 mins, p = 0.05). Procedural times were lower in HPSD, although not significant (133.7 vs 150.8 mins, p = 0.10). Post ablation endoscopy showed 4 cases of ETI (4.5%), with equal occurrence in HPSD and LPLD (p = 1.0). All ETIs were class 2a (superficial ulcer), and treated with PPI therapy. Esophageal injuries not attributable to RF ablation occurred in 9 (10%), with no difference between groups (p = 0.29). There was no difference in AF recurrence between the 2 groups (post 3 months blanking period) after a mean follow up of 6.3 months (p = 0.71). Conclusion HPSD ablation was associated with lower RF ablation and fluoroscopy times compared to LPSD, with comparably low rates of ETI on post ablation endoscopy. Our findings suggest that HPSD ablation is a safe and efficacious approach to PVI. However clinicians should be cognisant of the potential injury risk related to esophageal instrumentation from transesophageal echo/ ETM probes.

Beyond pulmonary vein isolation for persistent atrial fibrillation: sequential high-resolution mapping to guide ablation

PurposeWe aimed to evaluate whether outcomes with ablation in persistent (PsAF) and long-standing persistent (LsPsAF) AF can be improved beyond what can be achieved with pulmonary vein isolation (PVI) alone, using individualized mapping to guide ablation.MethodsWe studied 20 pts (15 M, 68 ± 11y) with PsAF (14) or LsPsAF (6) referred for first-time AF ablation. Following antral PVI, individualized mapping (IM) was performed using a high-density mapping catheter stably and fully deployed for 30 s at each of 23 ± 9 sites per patient. Activation data were reviewed, and an ablation strategy designed to intersect areas of focal and rotational activity. Mean follow-up was 429 ± 131 days. The study population was compared to a matched contemporary control cohort (CC) of 20 consecutive patients undergoing conventional ablation.ResultsDespite the IM group having a higher median comorbidities score, 3.5 vs. 2.5 in the CC group, indicating potentially more complex patients and more advanced substrate, cumulative freedom from AF after a single procedure was achieved in 94% of patients in the IM group vs. 75% in the CC group at 1 year and remained the same in both groups at the conclusion of the study (p = 0.02). There was a similar trend in atrial arrhythmia-free survival between both groups (84% vs. 67% at 1 year) that did not reach statistical significance. The procedure duration was longer in the IM group by a median of 31.5 min (p = 0.004).ConclusionsIndividualized mapping to guide AF ablation appears to achieve significantly greater AF-free survival compared to conventional PVI when applied as a primary ablation treatment. The results of this pilot study need to be confirmed in a larger, randomized trial.

ОТДАЛЕННЫЕ РЕЗУЛЬТАТЫ МИНИИНВАЗИВНОЙ ЭПИКАРДИАЛЬНОЙ ВИДЕОАССИСТИРОВАННОЙ РАДИОЧАСТОТНОЙ ИЗОЛЯЦИИ ЛЕГОЧНЫХ ВЕН ПРИ ИЗОЛИРОВАННОЙ ФИБРИЛЛЯЦИИ ПРЕДСЕРДИЙ

Aim. To analyze long-term results of the use of minimally invasive epicardial video-assisted radiofrequency ablation (RFA) of the pulmonary veins (PV) in patients with various forms of isolated atrial fibrillation (AF). Materials and methods. Since February 2011 to December 2014, 22 patients (male/female – 21/1) with paroxysmal / persistent / long-standing persistent idiopathic form of AF were operated on the basis of the Republican Scientific and Practical Center “Cardiology”, 7 (31.8%) / 9 (41%) / 6 (27.2%) cases respectively. Mean age was 48.33 ± 9.37 (31–66) years old. The average duration of the history of AF before the operation was 58.6 ± 32.5 months. RFA was performed through a bilateral mini-thoracotomy approach using video endoscopy with the application of bipolar irrigated Gemini X ablative clamp electrodes. All patients underwent bilateral antral RFA isolation of the PVs. In 100% of patients it was possible to achieve a conduction block from the PV collectors. Results. During the hospital period, there were not no lethal cases, conversions to sternotomy, and neurological complications. The long-term period was studied in 100% of patients, the average follow-up period was 7.4+0.5 years. The final rhythm was assessed using Holter monitoring in 3, 6, and 12 months after surgery, then annually. In 6 (28%) cases in patients with initial non-paroxysmal AF, endocardial RFA of the isthmus of the right atrium or PV orifices was performed at different times after surgery due to the presence of atrial flutter (4/19%) or AF (2/9.5%). Implantation of the pacemaker was required in 2 cases (9.0%). The ef fectiveness of bipolar antral RFA isolation of the PV using the Gemini X device, depending on the initial form of AF in the long-term period: paroxysmal – 100%, persistent – 66.7%, long-term persistent – 33.3%. Conclusion. Epicardial minimally invasive bipolar antral PV isolation is a highly effective treatment for paroxysmal AF. In non-paroxysmal forms of AF, it is necessary to expand isolation of arrhythmogenic zones in the atria.

Atrial fibrillation in heart failure: Prime time for ablation!

Among heart failure (HF) patients, the onset of atrial fibrillation (AF) is often associated with a marked worsening of HF symptoms and increased morbidity and mortality. Among AF patients, 30%–40% experience at least 1 HF episode. New data suggest that, in HF patients, AF rhythm control is superior to rate control and that rhythm control by catheter ablation is superior to antiarrhythmic drugs. In recent years, several trials that addressed the impact of AF ablation on morbidity and mortality included HF patients; however, studies also have specifically investigated the growing cohort of patients suffering from both HF and AF. Although the majority of these trials showed a marked benefit of AF ablation, there are hints that not all HF patients benefit equally from AF ablation. AF treatment in HF is challenging because the same cardiac morbidities that lead to HF can also act as risk factors for the development of the arrhythmogenic substrate that causes AF. In many patients, this arrhythmogenic substrate can be successfully treated by antral pulmonary vein isolation pulmonary vein isolation (PVI). However, due to advanced atrial disease, some patients also might require multiple procedures and/or “PVI plus” ablation strategies. In this review, we summarize current data on the effect of AF ablation in HF patients, with a special focus on the beneficial effect of AF ablation in different clinical HF subgroups.

Withdrawal: Prospective randomized comparison between upgraded "2C3L" versus PVI approach for catheter ablation of persistent atrial fibrillation: PROMPT-AF trial design.

Background In randomized studies, the strategy of pulmonary vein (PV) antral isolation (PVI) plus linear ablation has failed to increase success rates for persistent atrial fibrillation (PeAF) ablation when compared with PVI alone. Peri-mitral reentry related atrial tachycardia due to incomplete linear block is an important cause of clinical failures of a first ablation procedure. Ethanol infusion (EI) into the vein of Marshall (EI-VOM) has been demonstrated to facilitate a durable mitral isthmus linear lesion. Objective This trial is designed to compare arrhythmia-free survival between PVI and an ablation strategy termed upgraded '2C3L' for ablation of PeAF. Study design The PROMPT-AF study is a prospective, multicenter, randomized trial involving blinded assessment of outcomes. Patients (n = 276) undergoing their first catheter ablation of PeAF will be randomized to either the upgraded '2C3L' arm or PVI arm in a 1:1 fashion. The upgraded '2C3L' technique is a fixed ablation approach consisting of EI-VOM, bilateral circumferential PVI and three linear ablation lesion sets across the mitral isthmus, left atrial roof, and cavo-tricuspid isthmus. The follow-up duration is 12 months. The primary endpoint is the rate of documented atrial tachycardia arrhythmias of >30 seconds, without any antiarrhythmic drugs, in 12 months after the index ablation procedure (excluding a blanking period of 3 months). Conclusions The PROMPT-AF study will evaluate the efficacy of the fixed '2C3L' approach in conjunction with EI-VOM, compared with PVI alone, in patients with PeAF undergoing de novo ablation. This article is protected by copyright. All rights reserved.

B-PO05-088 SINGLE-SHOT LATTICE TIP CATHETER FOR PULMONARY VEIN ISOLATION WITH PULSED FIELD ABLATION

Pulsed-field ablation (PFA) is a nonthermal energy with potential safety advantages for pulmonary vein isolation (PVI). To examine a novel PFA system that includes an expandable over-the-wire multielectrode lattice tip catheter and electroanatomical mapping system (EAM) for single-shot PVI. This system includes an 8F over-the-wire compressible lattice tip catheter that expands to a dimeter of up to 34mm for antral PVI (Sphere PVI™, Affera Inc., Figure) and an EAM system (Prism-1™). PFA is applied from six elements surrounding the equator using a biphasic waveform of microsecond scale (5 secs per application). In 8 swine, the superior vena cava (SVC) and right superior pulmonary vain (RSPV) were targeted for isolation (entrance and exit block). Animals were survived for 3 wks (n=4) and 24 hrs (n=4) for evaluation of temporal lesion durability and tissue effects. Pre and post contrast venography evaluated vessel diameter. In 8 animals, the catheter was positioned in an antral venous position and 2-3 applications (total PFA time 10-15sec) produced successful isolation. All targeted veins remained isolated in all animals. The Figure shows a representative example of 3-week post ablation voltage maps demonstrating chronic wide isolation of the SVC and RSPV. Contrast venography showed no changes in RSPV diameter (P=NS), and phrenic nerve function remained intact. Histopathological analysis demonstrated well demarcated lesions comprised of collagen. In this pre-clinical study, a single-shot lattice PFA catheter produced rapid, antral and durable PVI.

B-PO05-080 SIMULTANEOUS INTRACARDIAC AND BODY-SURFACE NONCONTACT MAPPING OF ATRIAL FIBRILLATION

The high recurrence rate of persistent AF after PVI has led to interest in the underlying substrate maintaining AF. Rotational activity, slow conduction, and automatic activity have been proposed. No methods to identify critical sites have been validated through convincing clinical trials, and no gold standard exists to evaluate the commercially available mapping systems applicable to this purpose. To report initial observations while simultaneously using intracardiac and body-surface noncontact methodologies to map persistent atrial fibrillation. A 69 yo male with persistent AF underwent cryoballoon PVI. Noncontact mapping was then performed using the Cardioinsight vest (Medtronic, Mounds View, MN) and AcQmap 6-splined catheter (Acutus, Carlsbad, CA) placed in the left atrium. The two systems simultaneously recorded and analyzed 15 seconds of activation data. Results were compared. The figure shows the Voltage map and the noncontact maps. The body-surface system revealed copious rotational activity at the border of the left inferior pulmonary vein antral isolation line. There were no other significant sites on the map. The intracardiac map revealed a corresponding pattern of slow conduction and rotational activity across the same area. This first in human comparison of body-surface and intracardiac noncontact mapping of persistent AF produced strikingly similar results, and thus circumstantial evidence validating the data from both systems. Further experience with these systems will reveal whether they indeed confirm, or perhaps complement, each other in the search for the underlying substrate which maintains AF.

B-PO05-138 CATHETER ABLATION OF ATRIAL FIBRILLATION IS NOT ASSOCIATED WITH DESTRUCTION OF CARDIAC AFFERENTS DRIVING VOLUME-REGULATING AUTONOMIC REFLEXES

We have previously shown abnormal cardiac volume-sensitive reflexes (whose receptors are co-located in veno-atrial tissue) in AF patients. Whether unintended nerve disruption from Pulmonary Vein Isolation (PVI) could also occur is unknown. To evaluate whether PVI disrupts afferent volume-sensitive reflexes. We consecutively studied paroxysmal/persistent AF patients pre-PVI (n =18) and recontacted them for a post-PVI visit. We excluded those with AF recurrence/procedural complications, allowing redo procedures if AF-free >6 months. A cohort of 9 patients consented to both visits. We measured beat-to-beat mean arterial pressure (MAP) and heart rate (HR) continuously while testing reflex vasoconstriction from Lower Body Negative Pressure (LBNP), which offloads veno-atrial volume receptors, using forearm blood flow (FBF∝1/vascular resistance), at 0, -20 & -40 mmHg LBNP by venous occlusion plethysmography. We withheld anti-hypertensives/arrhythmics (5 half-lives). Mean age was 64±3 years; 78% male; BMI 28±1 kg/m2; LA size 37±2 ml/m2; and left ventricular function 65±3 %. We performed single ring radiofrequency PVI (PV and posterior wall, n=7); cryoablation (n=1) and wide antral PVI (n=1). Redo in n=2. During LBNP, MAP decreased slightly both pre (-1.6±3%) and post-PVI (-2.8±1.8%); P=0.7. HR increased similarly (P=0.7) pre (10.6±6.4%) and post-PVI (7.2±1.5%). FBF was unchanged (P=0.8), Figure. The reflex response to decreased cardiac volume is not altered by PVI. More work to assess other lesion sets or ganglionated plexi ablation is needed to ensure absence of adverse autonomic remodelling due to catheter ablation for AF.

B-PO03-088 ATRIAL FIBRILLATION TERMINATION AND FREEDOM FROM ATRIAL FIBRILLATION IS ASSOCIATED WITH ABLATION OF ATRIAL REGIONS WITH HIGHER RIPPLE FREQUENCY

Persistent atrial fibrillation (AF) is a complex arrhythmia with multiple pathophysiologic mechanisms. Achieving a high rate of freedom from AF post ablation has been challenging. Carto® Ripple map has previously been identified as one possible method to improve ablation outcomes. The purpose of this study was to evaluate a novel CARTO® software algorithm based on CARTO® Ripple map for automated detection of visually identified high Ripple frequency locations, and the relationship of these sites to AF termination and 18 month freedom from AF. Consecutive patients underwent first time ablation for persistent AF. A high-density Ripple map was created using a Pentaray catheter. If AF did not terminate with pulmonary vein antral isolation, ablation was performed at sites with visually identified fast Ripple activations until AF termination, a protocol previously described and published by us. Patients were followed 18 months for rhythm outcome. Retrospectively analysis was then performed using a novel CARTO® software algorithm developed to analyze Ripple frequency, defined as the number of Ripple identified changes in dV/dT per second. A total of 69 maps from 38 patients (mean age 65.6, 65.8% male) were analyzed. A mean of 11.8 ± 4.9 electrograms per cm2 were present on which the automated Ripple Frequency maps were generated. The Ripple frequency ranged from 0 to 140 Ripple activations per second and the top quartile of Ripple frequency corresponded to a visual reference with 95.0% sensitivity and 88.4% specificity. AF was observed to terminate with ablation in 94.7% of patients; PV antrum alone (21.1%), or PV plus non antral sites (78.9%). The three most common non-PV antral locations were LA septum 66.7%, LA roof 61.1%, and Inferior LA 38.9%. The top quartile of Ripple frequency was present in non-PV sites necessary for AF termination with an 89.6% sensitivity and 91.4% specificity. On follow up of 18 months, 37 of 38 patients (97.4%) were free of AF. This novel algorithm for automated analysis of CARTO® Ripple frequency demonstrated a good sensitivity and specificity for detecting atrial regions in persistent AF where ablation is associated with both termination and a high freedom from AF after 18 months.

Significance of electrical activity in the right superior pulmonary vein post-isolation and relationship to superior vena cava potentials.

After antral pulmonary vein isolation (PVI), electrical potentials may persist deep in the right superior pulmonary vein (RSPV). Whether these potentials signify true pulmonary vein potential (PVP) (implying inadequate RSPV isolation) or are far-field potentials (FFP) from the superior vena cava (SVC) is unclear. Here, we attempt to assess the incidence of persistent potentials in RSPV post-isolation and methods to differentiate PVP from FFP. Following PVI, we mapped the RSPV and the SVC with simultaneously placed catheters. We recorded the incidence of SVC potentials, RSPV potentials, and distance between the 2 structures. When RSPV potentials were present, we assessed (1) relationship to SVC potentials, (2) RSPV-SVC distance, and (3) responses on pacing from either site. Among 43 consecutive post-PVI patients, 39 (91%) patients had SVC electrical activity but only 10 had persistent RSPV potentials. Of these, 2/10 had true PVP, and 8 were FFP from SVC. Bipolar electrogram morphology did not differentiate PVP from FFP, but low-amplitude (5mA) SVC pacing was an effective maneuver. However, high-amplitude (≥ 10mA) pacing from SVC and/or RSPV could result in far-field capture of the other site even when RSPV was devoid of electrical activity. Average RSPV-SVC distance was 15.9mm. Persistent RSPV potentials occur rarely post-PVI despite the close proximity to electrically active SVC. When present, true PVP can be differentiated from FFP by low-amplitude pacing from SVC. Bipolar EGM morphology and high-amplitude pacing are unreliable at differentiating these potentials.

Atrial substrate characterization in patients with atrial fibrillation and hypertrophic cardiomyopathy: Evidence for an extensive fibrotic disease

IntroductionData regarding the left atrial (LA) electroanatomical substrate in patients with hypertrophic cardiomyopathy (HCM) and atrial fibrillation (AF) are missing. In this electroanatomical mapping (EAM) study, we evaluated the extent of LA fibrosis and its impact on catheter ablation outcomes in patients with HCM and AF. Materials and methodsHigh-density LA EAM was performed during AF in 28 consecutive patients with obstructive HCM and AF (42.9% displayed paroxysmal AF and 57.1% persistent AF). Propensity score (PS) matching analysis was performed to reduce the impact of potential confounding factors. PS were derived to match patients at a 1:1 ratio. Patients were matched according to age, sex and LA diameter. After PS, 28 non-HCM patients with AF were selected, and served as controls. Two different cut-off values of bipolar signal amplitude were investigated for fibrosis characterization (≤0.25 mV and ≤ 0.4 mV). HCM patients underwent pulmonary vein antral isolation (PVAI) and roof line, while non-HCM patients PVAI only. ResultsAfter the 3-month blanking period, 10 HCM patients (35.7%) displayed atrial arrhythmia recurrence. HCM patients with arrhythmia recurrence showed significantly greater low voltage areas defined as either bipolar voltage ≤0.25 mV (22.5 ± 10% vs. 5.5 ± 6.4%, p = 0.001) or ≤ 0.4 mV (32 ± 13.9% vs. 5.9 ± 5.1%, p < 0.001). The presence of low voltage areas ≤0.4 mV greater than 14.1% of the total LA area also predicted arrhythmia recurrence with excellent sensitivity (100%) and specificity (100%). Univariate analysis revealed that the extent of LA fibrosis was the only predictor of AF recurrence. After PS matching with non-HCM patients, patients with HCM exhibited wider fibrotic regions ≤0.25 mV compared to non-HCM patients (p = 0.016). ConclusionsHigh-density EAM reveals extensive LA fibrotic disease in patients with HCM, an event with certain implications in catheter ablation outcomes.

Arrhythmia Termination During Radiofrequency Delivery Improves Outcomes after Catheter Ablation for Persistent and Long Standing Persistent Atrial Fibrillation

Abstract Background Achieving long-term successful outcomes with catheter ablation (CA) of persistent atrial fibrillation (PsAF) remains a challenge. Multiple attempts to determine effective ablation strategies besides the pulmonary veins (PV) were made but, so far, there is no agreed standard approach and no clear consensus as to which is the best one. Among the most frequently used techniques was ablation of complex atrial fractionated electrograms (CFAE) but studies showed contradictory results. The optimal procedural endpoint also needs further refinement. Objectives We sought to evaluate outcomes in regard to patient characteristics and procedural termination. We also aimed to assess whether continuation of antiarrythmic therapy in the blanking period (1 to 3 months after the procedure) influences long term results. Methods We enrolled consecutive patients with persistent and long-standing PsAF (LS-PsAF) who underwent one or more radiofrequency catheter ablations (RF CA) - pulmonary vein antral isolation (PVAI), followed by CFAE or resultant atrial tachycardia/flutter elimination, were retrospectively analyzed. Procedural objective was tachyarrhythmia (AF or resultant atrial flutters/tachycardias) termination (TT) to sinus rhythm (SR) during RF delivery. If after extensive substrate based or activation guided ablation sinus rhyhtm was not restored, conversion was performed with antiarrhythmic drugs (AAD), overdrive pacing or electrical shock. Screening for arrhythmia recurrence was performed via clinical interview and 48 hours Holter monitoring at 1,3 and 6 months and then every 6 months. Results The cohort included 94 patients (age 54.5±11.4, 67 (71%) males, CHADSVASc 2.3±2, 11 (12%) LS-PsAF) Acute restoration of sinus rhythm (SR) was achieved in 93.4% of the cases, 43% by ablation of CFAE or resultant atrial tachycardia/flutter(AT/AFL), 36.2% by electric cardioversion, 7.4% by chemical conversion, 3.1 % overdrive pacing, 3.7 % spontaneuous/mechanical. The long term success rate after a mean of 1.7±0.8 procedures was 59% at a mean follow-up period of 80±28 months. Freedom from AF was significantly higher when arrhythmia termination was obtained during RF delivery (p – 0.003). Short-term use of AAD in the blanking period did not lead to improved long term outcomes. Conclusions In patients with PsAF and LS-PsAF restoration of sinus rhyhtm during RF delivery for pulmonary vein isolation, ablation of CFAE or resultant atrial tachyarrhythmia predicts long term procedural success. Further research to determine the best strategy to achieve this outcome is necessary.

Does pulsed field ablation regress over time? A quantitative temporal analysis of pulmonary vein isolation

The tissue specificity of pulsed field ablation (PFA) makes it an attractive energy source for pulmonary vein (PV) isolation (PVI). However, beyond each PFA lesion's zone of irreversible electroporation and cell death, there may be a surrounding zone of reversible electroporation and cell injury that could potentially normalize with time. The purpose of this study was to assess whether the level of electrical PVI that is observed acutely after PFA regresses over time. In a clinical trial, patients with paroxysmal atrial fibrillation underwent PVI using a biphasic PFA waveform delivered through a dedicated, variably deployable multielectrode basket/flower catheter. Detailed voltage maps were created using a multispline diagnostic catheter immediately after PFA and again ∼3 months later in a prospective, protocol-specified reassessment procedure. We analyzed 20 patients who underwent PFA with durable PVI and available maps from both time points. To compare the ablated zones, the left- and right-sided PV antral isolation areas and nonablated posterior wall area were quantified and the distances between left and right PV low-voltage edges were measured. A comparison of voltage maps immediately after PFA and at a median of 84 days (interquartile range 69-90 days) later revealed that there was no significant difference in either the left- and right-sided PV antral isolation areas or nonablated posterior wall area. The distances between low-voltage edges on the posterior wall were also not significantly different between the 2 time points. This study demonstrates that the level of PV antral isolation after PFA with a multielectrode PFA catheter persists without regression.

Association between left atrial wall thickness and residual potential after pulmonary vein antral isolation in patients with atrial fibrillation receiving Ablation Index-guided ablation

Abstract Background For the improvement of efficacy in radiofrequency catheter ablation (RFCA) of pulmonary vein isolation (PVI) in patients with atrial fibrillation (AF), fixed target Ablation Index (AI) value has been recommended regardless of individual and regional differences of left atrial wall thickness (LAWT). Objective To evaluate the association between LAWT and residual potential (RP) after first pass encirclement of PVI in AF patients receiving AI-guided PVI. Method A total of 116 patients (29% persistent AF) undergone AF RFCA using AI-guided PVI were included. Using SmartTouch catheter or SmartTouch SF catheter (Biosense Webster Inc., CA, US), point-by-point ablation was delivered at 30–40W on the anterior/roof segments and 25–30W on the posterior/inferior/carina segments. AI targets were 450 on the anterior/roof segments and 350 on the posterior/inferior/carina segments. After first encirclement of PVI was performed, RP was evaluated. LAWT was evaluated by 3-dimensional wall thickness map using computed tomographic images. LAWT values of ablation regions were graded by LAWT in each segment of PV antrum (Figure). Results Among a total of 1564 PV segments, RP was observed in 106 segments (6.8%). Left superior, inferior PV ridges and right superior PV roof segments were the most, second, and third thickest area among 14 PV segments (mean LAWT grade 5.09±1.08, 3.34±1.70, and 2.32±1.11, respectively). Mean LAWT grade was lower in segments with RP than those in without RP (2.74±1.80 vs. 2.07±1.28, p&amp;lt;0.001, Figure). In segments applied AI 450 (anterior/roof), segments with RP showed significantly thicker LAWT than those without RP (mean LAWT grade 3.65±2.01 vs. 2.57±1.56, p&amp;lt;0.001). In posterior/inferior/carina segments applied AI 350, there was no significant difference in mean LAWT between segments with and without RP (1.80±0.77 vs. 1.75±0.83, p=0.744). Conclusion Delivering same AI during PVI, thicker LAWT was associated with higher incidence of RP after first pass encirclement of PV in anterior/roof area. Tailored AI should be considered by LAWT to improve acute outcome of PVI. LAWP RP Funding Acknowledgement Type of funding source: None

Improving pulmonary vein isolation during cryoballoon ablation using the re-look angiography technique

Abstract Background Cryoballoon ablation for pulmonary vein (PV) antral isolation is contact-dependent. Currently, occlusion assessment using the cryoballoon is most commonly performed using contrast venogram prior to ablation. However, there is a known difference in balloon size/shape between the inflated and ablation state, due to significant increase in cryoballoon pressure, which can cause potential undetected leak and, thus, failure of PV isolation. This phenomenon is currently not detected using standard techniques and effectiveness of mitigation techniques have not been assessed. Purpose We hypothesize that repeat injection of contrast five seconds after the initiation of cryoballoon ablation can be used to assess changes in shape and confirm ongoing occlusion during ablation; the re-look angiography technique. The incidence of PVI leak and the ability for the relook angiography to remedy the leak is assessed. Methods A total of 125 patients (440 PVs) undergoing cryoballoon ablation (Medtronic Arctic Front Advance Balloon™) were assessed using the re-look angiography technique unless they required occlusion with a segmental approach. Fifteen patients were excluded from contrast use due to renal insufficiency. Results Successful single occlusion was seen in 330 (75%) PVs and the re-look angiography technique was employed in each of those events. In 180 of the 330 (55%) single PV occlusions, a new PV leak undetected during the initial PV angiogram was identified. This prompted repositioning of the balloon to achieve complete PV isolation in 85 of 180 of the PV cases, with 95 of the cases requiring additional segmental ablation to complete full PV isolation. Conclusion A significant amount of insufficient PV antral contact during cryo-ablation may not be detected with conventional single PV angiography and may explain inadequate PV isolation. The re-look angiography technique is a simple tool to confirm robust balloon contact and guide repositioning as well as identify the need for additional segmental ablation. Additional follow up is needed for translation to improved clinical outcomes. Funding Acknowledgement Type of funding source: None

Longstanding Persistent Atrial Fibrillation Ablation: How Do You Perform It?

Longstanding-persistent atrial fibrillation is one of the most challenging arrhythmias to treat. While radiofrequency catheter ablation is highly effective in paroxysmal atrial fibrillation, pulmonary vein antral isolation (including posterior wall isolation) alone is not enough for nonparoxysmal atrial fibrillation, other targets should be sought in this population. In this case report, we will describe our approach in a typical patient presenting for a first-time ablation procedure for longstanding persistent atrial fibrillation.

Lesion durability after antral pulmonary vein isolation using a radiofrequency hot balloon catheter.

Antral pulmonary vein isolation (PVI) using a radiofrequency hot balloon catheter (RHB) is a feasible therapeutic option for treating atrial fibrillation (AF). Lesion durability after antral RHB-PVI remains unknown. This study aimed to evaluate lesion durability and the associations between procedural characteristics after antral RHB-PVI. A total of 200 patients received antral RHB-PVI using the single-shot technique between April 2016 and March 2018. Antral RHB-PVI was performed following a pre-specified protocol and RHB energy application was performed for a maximum of two times for each PV. Consecutive patients who underwent repeated procedures for recurrence of any type of atrial tachyarrhythmia were enrolled. Twenty-six (13%) patients underwent repeated ablation and 20 patient documented AF recurrence (AF group) and 6 patients documented non-AF recurrence (non-AF group). Repeated ablation was performed at a median (25th, 75th percentiles) of 378days (217, 487) after the initial procedure and durable PVI was observed in 86 (83.5%) PVs. Durability reached 89.7% when PVI was achieved only using an RHB. In the AF group (79 PVs), durable PVI was observed in 62 (78.5%) PVs, whereas all 24 PVs were still isolated in the non-AF group. The majority of reconnection sites were around the superior PVs. Antral RHB-PVI shows high lesion durability, especially with both inferior PVs.

Long-term clinical outcomes and prognostic indicators for focal impulse and rotor modulation guided ablation: A single-center observational study

BackgroundElectrophysiologists have developed a computational mapping approach to localize sources that may perpetuate persistent atrial fibrillation (AF). Focal impulse and rotor modulation (FIRM)-guided ablation of these sources have produced variable results. The current study further assesses single-procedure success rates of FIRM-guided ablation for preventing AF or atrial tachyarrhythmia recurrence and analyzes different baseline characteristics as prognostic indicators for individuals experiencing these undesired outcomes. MethodsSeventy-one consecutive patients (mean age 64.58 ± 9.05 years and 36.6% female) with drug-refractory persistent AF with and without prior history of pulmonary vein antral isolation (PVAI) underwent FIRM-guided ablation. Patients without prior history of PVAI underwent FIRM-guided ablation in addition to de novo PVAI. Patients with prior history of PVAI had the pulmonary veins reassessed at the time of FIRM-guided ablation for reconnection as well as re-isolation, when necessary. These patients were then prospectively followed for AF and atrial tachyarrhythmia recurrence. ResultsFIRM analysis revealed rotors in the right atrium in 66.2% (1.77 ± 1.53 mean rotors per patient) and in the left atrium in 85.9% (2.65 ± 1.52 mean rotors per patient) of patients analyzed in the current study. After a single FIRM-guided ablation procedure, AF and atrial tachyarrhythmia recurrence was demonstrated in 21.1% (15/71) and 33.8% (24/71) of patients, respectively. The entire cohort of patients were followed for a mean duration of 23.20 ± 8.38 months with the mean time to AF recurrence found to be 12.35 ± 10.44 months. Furthermore, valvular heart disease (i.e. moderate mitral or tricuspid regurgitation) was found to be a statistically significant independent predictor for AF recurrence following FIRM-guided ablation (p = .033). ConclusionsFIRM-guided ablation in combination with PVAI is a suitable and effective approach for symptomatic individuals with drug-refractory persistent AF with and without prior history of PVAI. Randomized controlled studies are warranted.