Faculty Bibliography

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: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:Vein of Marshall (VOM) ethanol ablation is effective in preventing recurrence in patients with persistent atrial fibrillation (AF) as a de novo strategy. There is minimal data on its use in recurrent AF. OBJECTIVE:We investigated the efficacy of VOM ethanol ablation for recurrence despite initial AF ablation. METHODS:Retrospective analysis was performed of persistent AF patients who underwent repeat ablation after an initial ablation for persistent AF. All patients had pulmonary vein isolation (PVI), posterior wall isolation (PWI), and cavotricuspid isthmus (CTI) during their previous ablation(s). At redo ablation, controls underwent confirmation and completion of previous ablation steps, substrate modification, and a search for non-PV triggers. Cases had additional VOM ethanol ablation combined with mitral isthmus ablation. RESULTS:One hundred and seven patients (49 VOM, 60 control) were included. There was no difference in AF recurrence at 1-year comparing VOM patients (47%) and controls (38%), (p = 0.39). Within the VOM group, the mean AF burden decreased from 38% preablation to 10% 12-months post (p = 0.003). The proportion of recurrent persistent AF decreased from 65% preablation to 26% post (p = 0.004). There was no significant difference in reduction in AF burden or proportion of recurrent persistent AF when comparing VOM cases and controls. Six percent of VOM patients developed intraprocedural left atrial appendage (LAA) isolation. CONCLUSIONS:In patients with previous PVI, PWI, and CTI ablation, VOM ethanol ablation did not demonstrate a reduction in AF recurrence or burden when compared with a strategy of substrate modification and trigger ablation alone and increases the risk of LAA isolation.

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.

AIMS/UNASSIGNED:We aimed to develop and externally validate a convolutional neural network (CNN) using sinus rhythm electrocardiograms (ECGs) and CHARGE-AF features to predict incident paroxysmal atrial fibrillation (AF), benchmarking its performance against the CHARGE-AF score. METHODS AND RESULTS/UNASSIGNED:We curated 157 192 sinus ECGs from 76 986 patients within the New York University (NYU) Langone Health system, splitting data into training, validation, and test sets. Two cohorts, from suburban US outpatient practices and Greek tertiary hospitals, were used for external validation. The model utilizing the sinus ECG signal and all CHARGE-AF features achieved the highest test set area under the receiver operator curve (AUC) (0.89) and area under the precision recall curve (AUPRC) (0.69), outperforming the CHARGE-AF score alone. Model robustness was maintained in the external US cohort (AUC 0.90, AUPRC 0.67) and the European cohort (AUC 0.85, AUPRC 0.78). Subgroup analyses confirmed consistent performance across age, sex, and race strata. A CNN using ECG signals alone retained strong predictive ability, particularly when simulating missing or inaccurate clinical data. CONCLUSION/UNASSIGNED:Our CNN integrating sinus rhythm ECGs and CHARGE-AF features demonstrated superior predictive performance over traditional risk scoring alone for detecting incident paroxysmal AF. The model maintained accuracy across geographically and clinically diverse external validation cohorts, supporting its potential for broad implementation in AF screening strategies.

• LAAO devices are used for patients with AF intolerant of anticoagulation. • Periprocedural multimodality imaging is crucial for successful device deployment. • LAAs with bifid morphologies are uncommon and pose procedural challenges. • We describe closure of a bifid LAA using 2 side-by-side lobe-and-disk devices.