Impact of Left Atrial Bipolar Electrogram Voltage on First Pass Pulmonary Vein Isolation During Radiofrequency Catheter Ablation

Predictors of first-pass isolation in patients with recurrent atrial fibrillation: A retrospective cohort study

Background

Pulmonary vein isolation (PVI) is superior to antiarrhythmics for the management of atrial fibrillation, but repeat ablation is often required for durable rhythm control. Factors influencing first-pass isolation (FPI) and whether FPI predicts durable isolation are not well known.

Objective

The study sought to determine factors associated with FPI and rates of chronic reconnection among those with and without FPI at index PVI in patients undergoing repeat ablation.

Methods

We retrospectively identified 483 patients at our institution who underwent first-time PVI in 2021. Of these, 63 who had repeat ablation between 2021 and 2023 were included in the study. Logistic regression was used for statistical analysis for predictors of FPI during index PVI.

Results

The mean age was 65 years, 67% of patients were male, 90% were White, and 73% had persistent atrial fibrillation. At index PVI, FPI was achieved in 58% of left pulmonary veins (PVs), 48% of right PVs, and 25% of posterior wall isolations. Bilateral FPI was achieved in 35% of patients. At redo PVI, the right superior PV (47%) was most frequently reconnected. Lack of PFI of the right PVs at index PVI was associated with a 14-fold risk of chronic reconnection. Elevated left atrial voltage predicted the absence of FPI of the right PVs but not the left PVs.

Conclusion

Increased left atrial voltage predicts a lack of FPI in the right PVs but not in the left PVs. Lack of FPI of right PVs predicts chronic reconnection.

Predictors of first pass isolation of the pulmonary veins in real world ablations: An analysis of 2671 patients from the REAL-AF registry

INTRODUCTION

During atrial fibrillation ablation (AFA), achievement of first pass isolation (FPI) reflects effective lesion formation and predicts long-term freedom from arrhythmia recurrence. We aim to determine the clinical and procedural predictors of pulmonary vein FPI.

METHODS

We reviewed AFA procedures in a multicenter prospective registry of AFA (REAL-AF). A multivariate ordinal logistic regression, weighted by inverse proceduralist volume, was used to determine predictors of FPI.

RESULTS

A total of 2671 patients were included with 1806 achieving FPI in both vein sides, 702 achieving FPI in one, and 163 having no FPI. Individually, age, left atrial (LA) scar, higher power usage (50 W), greater posterior contact force, ablation index >350 posteriorly, Vizigo™ sheath utilization, nonstandard ventilation, and high operator volume (>6 monthly cases) were all related to improved odds of FPI. Conversely sleep apnea, elevated body mass index (BMI), diabetes mellitus, LA enlargement, antiarrhythmic drug use, and center's higher fluoroscopy use were related to reduced odds of FPI. Multivariate analysis showed that BMI > 30 (OR 0.78 [0.64-0.96]) and LA volume (OR per mL increase = 1.00 [0.99-1.00]) predicted lower odds of achieving FPI, whereas significant left atrial scarring (>20%) was related to higher rates of FPI. Procedurally, the use of high power (50 W) (OR 1.32 [1.05-1.65]), increasing force posteriorly (OR 2.03 [1.19-3.46]), and nonstandard ventilation (OR 1.26 [1.00-1.59]) predicted higher FPI rates. At a site level, high procedural volume (OR 1.89 [1.48-2.41]) and low fluoroscopy centers (OR 0.72 [0.61-0.84]) had higher rates of FPI.

CONCLUSION

FPI rates are affected by operator experience, patient comorbidities, and procedural strategies. These factors may be postulated to impact acute lesion formation.

Index-Guided High-Power Radiofrequency Catheter Ablation for Atrial Fibrillation: A Systematic Review and Meta-Analysis Study

PURPOSE OF REVIEW

Studies have suggested the superiority of high-power compared to standard-power radiofrequency ablation ablation (RFCA). This study aimed to assess the efficacy and safety of high-power compared to standard-power RFCA guided by ablation index (AI) or lesion index (LSI).

RECENT FINDINGS

A systematic review and meta-analysis study comparing IGHP and IGLP approaches for AF ablation was conducted. The relevant published studies comparing IGHP and IGSP methods for RFCA in AF patients until October 2022 were collected from Cochrane, ProQuest, PubMed, and ScienceDirect. A total of 2579 AF patients from 11 studies were included, 1682 received IGHP RFCA, and 897 received IGSP RFCA. To achieve successful pulmonary vein isolation (PVI), the IGHP RFCA group had a significantly shorter procedure time than the IGHP RFCA group (mean difference (MD) -19.91 min; 95% CI -25.23 to -14.59 min; p < 0.01), radiofrequency (RF) application time (MD -10.92 min; 95% CI -14.70 to -7.13 min; p < 0.01), and fewer number of lesions (MD -10.90; 95% CI -18.77 to -3.02; p < 0.01) than the IGSP RFCA. First-pass PVI was significantly greater in the IGHP RFCA group than in the IGSP RFCA group (risk ratio (RR) 1.17; 95% CI 1.07 to 1.28; p < 0.01). The IGHP RFCA is an effective and efficient strategy for AF ablation. The superiority of IGHP RFCA includes the shorter procedure time, shorter RF application time, fewer number of lesions for complete PVI, and more excellent first-pass PVI.

Alterations of sympathetic dynamics after atrial fibrillation ablation by analysis sympathetic nerve activity provide prognostic value for recurrence and mechanistic insights into ablation

Background

Pulmonary vein isolation (PVI) is the cornerstone of atrial fibrillation (AF) ablation. Success is associated with autonomic function modulation; however, the relationship between the changes after ablation is not fully understood. We aimed to investigate the effect of ablation on autonomic modulation by skin sympathetic nerve activity (SKNA) using conventional electrocardiogram (ECG) electrodes and to predict the treatment success.

Methods

We enrolled 79 patients. We recorded neuECG for 10 min at 10 kHz before and after ablation. The NeuECG was bandpass-filtered (500–1,000 Hz) and integrated at intervals of 100 ms (iSKNA). iSKNA was averaged over different time windows (1-, 5-,10-s; aSKNAs), and burst analyses were derived from aSKNAs to quantify the dynamics of sympathetic activities. AF recurrence after 3 months was defined as the study endpoint.

Results

Sixteen patients experienced AF recurrence after the ablation. For burst analysis of 1-s aSKNA, the recurrence group had a higher bursting frequency than the non-recurrence group (0.074 ± 0.055 vs. 0.109 ± 0.067; p &lt; 0.05) before ablation. The differences between pre- and post-ablation of firing duration longer than 2 s were more in the non-recurrence group (2.75 ± 6.41 vs. −1.41 ± 5.14; p &lt; 0.05), while no significant changes were observed in the percentage of duration longer than 10 s using 5-s aSKNA. In addition, decreases in differences in firing frequency and percentage of both overall firing duration and longer firing duration (&gt; 2 s) between pre- and post-ablation were independently associated with AF recurrence and more area under receiver operating characteristics (ROC) curve in combination with CHADS2 score (0.833).

Conclusion

We demonstrated the applicability of neuECG for determining sympathetic modulation during AF ablation. Decreasing sympathetic activity is the key to successful ablation.

The effect of left atrial wall thickness and pulmonary vein sizes on the acute procedural success of atrial fibrillation ablation

Nowadays, a novel contact-force guided ablation technique is used for enclosing pulmonary veins in patients with atrial fibrillation (AF). We sought to determine whether left atrial (LA) wall thickness (LAWT) and pulmonary vein (PV) dimensions, as assessed by cardiac CT, could influence the success rate of first-pass pulmonary vein isolation (PVI). In a single-center, prospective study, we enrolled consecutive patients with symptomatic, drug-refractory AF who underwent initial radiofrequency catheter ablation using a modified CLOSE protocol. Pre-procedural CT was performed in all cases. Additionally, the diameter and area of the PV orifices were obtained. A total of 1034 LAWT measurements and 376 PV area measurements were performed in 94 patients (mean CHA2DS2-VASc score 2.1 ± 1.5, mean age 62.4 ± 12.6 years, 39.5% female, 38.3% persistent AF). Mean procedure time was 81.2 ± 19.3 min. Complete isolation of all PVs was achieved in 100% of patients. First-pass isolation rate was 76% and 71% for the right-sided PVs and the left-sided PVs, respectively. No difference was found regarding comorbidities and imaging parameters between those with and without first-pass isolation. LAWT (mean of 11 regions or separately) had no effect on the acute procedural outcome on logistic regression analysis (all p ≥ 0.05). Out of all assessed parameters, only RSPV diameter was associated with a higher rate of successful right-sided first pass isolation (OR 1.01, p = 0.04). Left atrial wall thickness does not have an influence on the acute procedural success of PVI using ablation index and a standardized ablation protocol. RSPV diameter could influence the probability of right sided first-pass isolation.

The Dissimilar Impact in Atrial Substrate Modificationof Left and Right Pulmonary Veins Isolation after Catheter Ablation of Paroxysmal Atrial Fibrillation

Since the discovery of pulmonary veins (PVs) as foci of atrial fibrillation (AF), the commonest cardiac arrhythmia, investigation revolves around PVs catheter ablation (CA) results. Notwithstanding, CA process itself is rather neglected. We aim to decompose crucial CA steps: coronary sinus (CS) catheterization and the impact of left and right PVs isolation (LPVI, RPVI), separately. We recruited 40 paroxysmal AF patients undergoing first-time CA and obtained five-minute lead II and bipolar CS recordings during sinus rhythm (SR) before CA (B), after LPVI (L) and after RPVI (R). Among others, duration, amplitude and atrial-rate variability (ARV) were calculated for P-waves and CS local activation waves (LAWs). LAWs features were compared among CS channels for reliability analysis. P-waves and LAWs features were compared after each ablation step (B, L, R). CS channels: amplitude and area were different between distal/medial (p≤0.0014) and distal/mid-proximal channels (p≤0.0025). Medial and distal showed the most and least coherent values, respectively. Correlation was higher in proximal (≥93%) than distal (≤91%) areas. P-waves: duration was significantly shortened after LPVI (after L: p=0.0012, −13.30%). LAWs: insignificant variations. ARV modification was more prominent in LAWs (L: >+73.12%, p≤0.0480, R: <−33.94%, p≤0.0642). Medial/mid-proximal channels are recommended during SR. CS LAWs are not significantly affected by CA but they describe more precisely CA-induced ARV modifications. LPVI provokes the highest impact in paroxysmal AF CA, significantly modifying P-wave duration.

Absence of first-pass isolation is associated with poor pulmonary vein isolation durability and atrial fibrillation ablation outcomes

BACKGROUND

Pulmonary vein (PV) reconnection is the main cause of atrial fibrillation (AF) recurrence. This study aimed to examine the effect of first-pass PV isolation (PVI) on PV reconnection frequency during the procedure and on AF ablation outcomes.

METHODS

This retrospective study included 446 patients with drug-refractory AF (370 men, aged 64 ± 10 years) who underwent initial PVI using an open-irrigated contact force catheter between January 2015 and October 2016. We investigated the effect of first-pass PVI on PV reconnection during spontaneous PV reconnection and dormant conduction after an adenosine triphosphate challenge.

RESULTS

First-pass PVI was achieved in 69% (617/892) of ipsilateral PVs, of which we observed PV reconnection during the procedure in 134 (22%) PVs. This value was significantly lower than that observed in those without first-pass PVI (50%, 138/275) (P < .0001). We divided the subjects into two groups based on the presence or absence of first-pass PVI in at least one of two ipsilateral PVs: first-pass (n = 383, 86%) and non-first-pass groups (n = 63, 14%). The 2-year AF recurrence-free rate was significantly higher in the first-pass group than in the other group (75% vs 59%, log-rank P = .032). In 78 patients with repeat AF ablation, the PV reconnection rate in the second procedure was significantly lower in PVs that had first-pass isolation in the first procedure (34% vs 73%, P < .0001).

CONCLUSIONS

Absence of first-pass PVI was associated with a higher frequency of spontaneous PV reconnection and dormant conduction and poor ablation outcomes. First-pass isolation may be a useful marker for better PVI durability.