Faculty Bibliography

Randomized trials of ethanol infusion into the vein of Marshall (EIVOM) have shown efficacy in preventing atrial fibrillation (AF) recurrence in patients presenting for de novo ablation. The utility of EIVOM in AF patients who present for redo ablation is unclear. This meta-analysis was reported according to the Preferred Reporting Items for Systematic Review and Meta-Analyses guidelines. Medline, Scopus, and Cochrane Central Register of Controlled Trials were systematically searched to identify relevant studies. Risk of bias was assessed using the Modified Newcastle-Ottawa scale. Eligible studies reported outcomes in AF patients with previous ablation who underwent redo catheter ablation (CA) alone vs. combined redo CA and EIVOM. Five observational studies comprising 568 patients were included. When comparing combined redo CA and EIVOM vs. redo CA alone, pooled results showed no difference in freedom from arrhythmia (FFA) in all patients (risk ratio [RR] 1.13; 95% confidence interval [CI] 0.96-1.33), FFA in persistent AF patients only (RR 1.08; 95% CI 0.90-1.29), total procedure time (mean difference -0.59; 95% CI -41.04-39.85), or major periprocedural complications (RR 0.81; 95% CI 0.06-11.64). Patients with AF recurrence after ablation represent a difficult-to-treat population. Salvage therapy with combined CA and EIVOM did not improve arrhythmic outcomes compared to CA alone in AF patients who presented for redo ablation.

BACKGROUND:Using high-frequency jet ventilation (HFJV) to improve catheter stability with conventional energy sources during atrial fibrillation (AF) ablation is associated with higher ablation success and improved arrhythmic outcomes. The utility of HFJV with pulsed field ablation (PFA) for AF is unclear. We investigated the utility of HFJV vs. standard ventilation in PFA for AF. METHODS:We studied consecutive cases of patients with AF undergoing PFA between 5/6/24 to 10/10/24. Procedural data collected included total procedure time and major periprocedural complications. Clinical data collected included atrial tachyarrhythmia (ATA) recurrence, stroke, and major bleeding at one-year follow-up. Outcomes were compared in cases where HFJV was used vs. standard ventilation. RESULTS:A total of 512 patients were included in this study (307 standard ventilation, 205 HFJV). There was no difference in ATA recurrence by Kaplan-Meier survival analysis between standard ventilation and HFJV groups (log rank test p = 0.59). When comparing standard ventilation vs. HFJV groups, there was no difference in ATA recurrence at one year (23% vs. 26%; p = 0.43), AF burden on continuous monitoring (9 ± 5% vs. 8 ± 24%; p = 0.85), total procedure time (114 ± 38 vs. 115 ± 33 min; p = 0.78), or major periprocedural complications (3% vs. 2%; p = 0.64). There was no difference in arrhythmic outcomes when patients were stratified by AF type and whether patients presented for first-time or redo ablation. CONCLUSION/CONCLUSIONS:Using HFJV in PFA for AF produces similar sinus rhythm maintenance overall and when stratified by AF type without affecting procedure times or complication rate.

BACKGROUND:Identifying nearfield and farfield signals is critical to mapping and ablating cardiac arrhythmias. This assessment is qualitative, depending on the "sharpness" of pulmonary vein (PV) electrograms. Electrogram peak frequency (PF) analysis is hypothesized to be a quantitative measure of signal proximity. OBJECTIVE:To confirm if PF defines nearfield versus farfield electrical signals and if it can be used during ablation to establish pulmonary vein isolation (PVI). METHODS:We created a cohort of 30 patients with AF undergoing PVI. Left atrial and PV maps of PF were generated before and after PVI. In the first 10 patients with paroxysmal AF (cohort 1), a cutoff value was selected to predict nearfield versus farfield signals. This cutoff was validated in a cohort of 10 patients with paroxysmal AF (cohort 2) and a cohort of 10 patients with persistent AF (cohort 3). RESULTS:PF was lower in farfield electrograms than nearfield electrograms. A PF cutoff of 300 Hz had a sensitivity of 93.2% (95% CI 81.3% - 98.6%) in cohort 1, 90.0% (95% CI 76.3 - 97.2) in cohort 2, and 98.6% (95% CI 90.1 - 99.7%) in cohort 3 for differentiating farfield from nearfield electrograms. The specificity was 100.0% (95% CI 98.2% - 100.0%) and the AUC was 0.99 (95% CI 0.97 - 1.00) in all patients. CONCLUSIONS:We confirmed the hypothesis that PF distinguishes nearfield from farfield electrograms. PF analysis improves the recognition of PV isolation. Mapping and ablation strategies utilizing PF should be pursued to improve ablation outcomes.

UNLABELLED:Oral anticoagulation (OAC) remains the primary means of stroke prevention in patients with atrial fibrillation (AF). However, there are patients at greater risk of bleeding or who have experienced major bleeding, whereby long term OAC is relatively contraindicated. Additionally, up to 55% of eligible AF patients do not utilize OAC. Thus, transcatheter left atrial appendage occlusion devices (LAAOD) present an attractive alternative to mitigate stroke risk. Randomized trials have demonstrated the noninferiority of LAAOD to OAC in reducing stroke risk. However, treatment with LAAODs presents its own risks, including the risk of device-related thrombus (DRT). In this report, we describe an unusual case of a patient with a small DRT initially identified on transesophageal echocardiography (TEE) 6 weeks after implantation of a Watchman FLX (Boston Scientific, Marlborough, MA, USA) LAAOD that was appropriately treated and resolved on TEE 6 months after implantation. However, a massive late DRT recurred 2 years after implantation. This case highlights the importance of continued device monitoring for unfavorable evolution of DRT beyond the currently recommended 45-day to 1-year monitoring period, and especially after suspected thrombus resolution. Furthermore, it underlines the importance of developing newer generation LAAOD that reduces DRT risk. LEARNING OBJECTIVE/UNASSIGNED:Left atrial appendage occlusion devices can mitigate stroke risk in atrial fibrillation patients with contraindications to oral anticoagulation. However, these devices present with their own risks, including the risk of device-related thrombus (DRT). This case highlights the importance of continued device monitoring for unfavorable evolution of DRT beyond the recommended 45-day to 1-year monitoring period.

BACKGROUND:Pulmonary vein isolation (PVI) and posterior wall isolation (PWI) are frequently used in the treatment of persistent atrial fibrillation (AF). Minimal data support adjunct PWI, possibly due to lack of durability via epicardial reconnections. OBJECTIVE:To determine the impact of very high output PW pace-capture testing in patients with persistent AF on AF/AT recurrence. METHODS:We performed a retrospective study of consecutive patients who underwent radiofrequency ablation for persistent AF and received PVI and PWI, as well as a cavotricuspid isthmus line (CTI). After the creation of three linear PW lesions (roof, carina-to-carina, and inferior PV levels), pace-capture testing was performed on the PW. The first cohort confirmed PWI using 10 mA at 2 ms (10 × 2) to pace capture. Sequentially, the second cohort utilized 20 mA at 10 ms (20 × 10). If the PW was captured, additional lesions were performed. Patients were excluded if additional lesion sets beyond PVI, PWI, and CTI were performed. RESULTS:A total of 232 patients were included. Of these, 129 (56%) patients were in the 20 × 10 group, and 103 (44%) patients were in the 10 × 2 group. The two groups did not differ in age, sex, proportion of comorbidities, presenting rhythm, left ventricular ejection fraction, or left atrial size. Despite the increase in procedure time and lesion number, in the time-to-event analysis, patients in the 20 × 10 group experienced recurrent AF/AT more frequently than those in the 10 × 2 group (log rank p = 0.01). CONCLUSION/CONCLUSIONS:Testing PWI in persistent AF with pace capture at 20 mA at 10 ms did not improve freedom from arrhythmia and may paradoxically be associated with harm. Our findings question whether PWI, regardless of durability, is effective in treating persistent AF.

INTRODUCTION/BACKGROUND:A lower frequency early electrogram (EGM) or broad area of early activation during premature ventricular contraction (PVC) mapping may be associated with a PVC origin in an opposing chamber or deep within the mapped surface. The utility of quantifying EGM frequency at early activation sites and isochronal activated surface area (IASA) is unclear. Our study aimed to investigate the utility of EGM frequency analysis and IASA mapping to complement activation mapping during PVC ablation. METHODS:High density PVC activation and IASA maps were created using a multi-electrode mapping catheter in 25 patients undergoing PVC ablation. EGMs in early activation regions were retrospectively studied. IASAs in each mapped chamber were analyzed. RESULTS:within 10 ms was unsuccessful. CONCLUSION/CONCLUSIONS:Higher EGM frequency and smaller IASA were associated with successful ablation of PVCs. Ablation at sites with EGM frequency > 325 Hz was successful in all patients. The utility of identifying higher frequency EGMs at early activation sites requires further study.

BACKGROUND:Prospective studies with a focus on the safety and effectiveness profile of stylet-driven left bundle branch area pacing (LBBAP) leads at both implant and chronic stages significantly contribute to a comprehensive perspective of utilizing SDL in this pacing modality. OBJECTIVE:Prospectively evaluate the performance and safety of LBBA-placed Solia S leads and the related impact on the patient's quality of life (QOL) through 12 months. METHODS:A multi-center, prospective, non-randomized trial enrolled patients with standard pacing indications in whom a Solia S lead was implanted in the left bundle branch area (LBBA). Adverse events and quality-of-life metrics were collected out to 12 months post implant along with threshold, sensing, and lead impedance data. RESULTS:For the 161 patients who experienced an SADE event or had at least 335 days of follow-up, the associated 12-month serious adverse device effect (SADE) rate was 0.02 events per subject-year [SADE-free rate of 98.1% (95% CI: 94.7%, 99.6%)]. The mean threshold was 0.98V at 0.4ms (vs. 0.84V at implant), mean sensing was 12.76mV (vs. 9.15mV at implant), and mean impedance was 521.8 ohms (vs. 670.5 ohms at implant). The mean change for the QOL physical function scale was +11.4 ± 24.0 (95% CI: 7.4, 15.4; t-value = 4.23; p < 0.001). CONCLUSION/CONCLUSIONS:These 12-month results utilizing the Solia S SDL demonstrate freedom from LBBAP lead-related complications, acceptable lead performance characteristics along with a significant coincident improvement in a patient's physical function.

BACKGROUND:Pulsed field ablation (PFA) is emerging as the preferred energy source for atrial fibrillation ablation, largely because of its promising safety profile, including lower risks of esophageal injury, pulmonary vein stenosis, and phrenic nerve injury. However, rare complications may only emerge after treating many thousands of patients. OBJECTIVES/OBJECTIVE:This study sought to determine the real-world utilization and safety profile of the pentaspline PFA catheter in the United States. METHODS:In this retrospective analysis, invitations were sent to U.S. centers performing PFA with the pentaspline catheter. Centers submitted data on patient demographics, procedural details, and adverse events (AEs). The main outcomes included the incidence of major and minor procedure-related AEs. RESULTS:Of the 435 centers contacted, 102 participated, averaging 5.1 operators per center (range 1-16 operators per center). Each center treated a median of 412 patients (range 26-1,961 patients), totaling 41,968 patients between February 2024 and July 2025. The median patient age was 68 years (range 17-99 years), and 56% were male. Most patients underwent first-time ablation (73%), primarily for paroxysmal (54%) or persistent atrial fibrillation (37%). Pulmonary vein isolation was performed in 93% of patients, with extravenous lesions on the posterior wall (57%), cavotricuspid isthmus (31%), or mitral isthmus (14%). Major AEs occurred in only 0.63% of patients, including cardiac tamponade (0.16%), vascular injury requiring intervention (0.18%), and stroke (0.10%). Importantly, no cases of esophageal fistula, persistent phrenic nerve paralysis, or pulmonary vein stenosis occurred. Mortality at 30 days was rare (0.04%), but there was a potential signal for rare (0.019%) unexplained sudden death/cardiac arrest. Rare AEs included coronary spasm (0.10%) and acute renal failure requiring dialysis (0.02%). Minor complications were reported in 2.05%, mainly vascular issues (0.96%), pericarditis (0.52%), and self-limited esophageal dysmotility (0.04%). CONCLUSIONS:In a real-world setting of unselected U.S. patients, PFA demonstrated a safety profile consistent with preferentiality to functional myocardial tissue ablation, without evidence of esophageal fistula or pulmonary vein stenosis. The major complication rate was ∼0.6%-mostly vascular AEs and pericardial tamponade. Stroke (∼1 in 1,000) and death (∼1 in 2,000) were rare. These data indicate that the initial implementation of pentaspline PFA has been overall safe.

BACKGROUND:Pulmonary vein (PV) isolation is the cornerstone of radiofrequency (RF) ablation for atrial fibrillation (AF) and PV reconnection is a common cause of recurrent AF. The relationship between PV ostial wall thickness (WT) and durable PV isolation is a matter of ongoing investigation. Additionally, the relationship between catheter impedance and WT is not well understood. We studied the relationship between PV ostial WT, ablation lesion metrics, and PV reconnection. METHODS:16 patients were identified who underwent an initial and redo AF ablation procedure and had a cardiac CTA analyzed using ADAS-3D imaging software performed prior to the initial ablation. Ablation lesion metrics from the initial ablation procedure were collected from the electroanatomic mapping software. Reconnected and isolated PV were identified based on electroanatomic mapping data collected at the redo AF ablation procedure. Patients with reconnected PV exhibited thicker left atrial walls (1.4 mm vs 1.2 mm, P < 0.05) and reconnected veins exhibited thicker ostial walls (1.7 mm, vs 1.5 mm, P < 0.05). LA volume, number of ablation lesions, and ablation lesion time were not significantly different between reconnected and isolated PV. Impedance drop during ablation was greater in patients with reconnected PV compared to patients with isolated PV (- 9.0 Ω vs - 6.6 Ω, P < 0.05). There was no correlation between PV ostial WT and ablation lesion impedance drop. CONCLUSION/CONCLUSIONS:PV reconnection was associated with thicker LA and PV ostial WT. Future studies will examine whether targeting thicker PV ostial tissue with more aggressive lesion metrics or different ablation technology can improve PV isolation and ablationoutcomes.