Faculty Bibliography

BACKGROUND:The optimal number of pulsed field ablation (PFA) applications during atrial fibrillation (AF) ablation is unclear. We hypothesized that the number of PFA applications would predict atrial tachyarrhythmia (ATA) recurrence rates. OBJECTIVE:To determine whether higher numbers of PFA applications would decrease ATA recurrence rates. METHODS:We studied cases of patients with AF undergoing first-time ablation with PFA between 5/6/24 and 10/7/24. All patients underwent pulmonary vein and posterior wall isolation. The primary outcome was ATA recurrence. Additional outcomes included stroke, post-procedural acute kidney injury (AKI), total procedure time, and major periprocedural complications. Univariable and multivariable analyses were performed to determine if the number of PFA applications predicted ATA recurrence. RESULTS:In a cohort consisting of 177 patients, univariable and multivariable analysis showed that the number of PFA applications split at the smallest quartile (< 57 applications) versus the largest three quartiles (≥ 57 applications) was the strongest predictor of ATA recurrence (p = 0.03). ATA recurrence at 1 year (29% vs. 8%; p < 0.01) and AF burden on continuous monitor (4% vs. 0%; p < 0.01) was higher with the standard (< 57 applications) vs higher (≥ 57 applications) PFA dose groups. When comparing the standard versus higher PFA dose groups, there was no difference in total procedure time (106 vs. 107 min; p = 0.77), major periprocedural complications (0% vs. 2%; p = 0.33), or post-procedural AKI (2% vs. 2%; p = 0.69). CONCLUSION/CONCLUSIONS:Increasing number of PFA applications is associated with reduced ATA recurrence. A higher number of PFA applications may decrease ATA recurrence without affecting procedure times or complication rate.

BACKGROUND:Intracardiac echocardiography (ICE) is widely used during electrophysiology and structural heart procedures; however, image interpretation remains operator-dependent and procedural views are not standardized. Although artificial intelligence has been increasingly applied to transthoracic and transesophageal echocardiography, applications to ICE remain limited. OBJECTIVES/OBJECTIVE:The objective of the study was to develop and evaluate Auto-Contour, a deep-learning pipeline for multistructure semantic segmentation of ICE anatomy and assess its feasibility for real-time procedural guidance. METHODS:In this retrospective multicenter study, 5,496 deidentified ICE cine loops from 249 procedures of unique patients, including routine clinical cases and the ViewFlex™ X first-in-human study, were analyzed. ICE experts classified each cine into 1 of 20 procedural views and annotated key anatomic structures, including the left atrium, left atrial appendage, pulmonary vein ostia, valves, cusps, papillary muscles, and left ventricle, at end-systole, and end-diastole, yielding 65,117 segmentations. A deep-learning segmentation model was trained using patient-level splits, standard augmentations, and early stopping. RESULTS:Segmentation performance was highest for larger cardiac chambers, with Dice scores of 0.94 for the left atrium and 0.82 for the left ventricle, and corresponding 95th-percentile Hausdorff distance values of 1.18 mm and 3.27 mm. Smaller structures also demonstrated acceptable performance, including the left atrial appendage, pulmonary veins, papillary muscles, and aortic cusps. The mean per-frame inference time was <0.03 seconds. CONCLUSIONS:Auto-Contour demonstrated robust multistructure segmentation of ICE anatomy with real-time inference, supporting prospective evaluation of artificial intelligence-assisted ICE for procedural standardization, efficiency, and safety.

BACKGROUND:Buckling of a transesophageal echocardiography (TEE) probe is a rare but potentially life-threatening complication that carries a significant risk of esophageal perforation. CASE SUMMARY/METHODS:We report 3 cases of buckled TEE probes that were promptly recognized, diagnosed, and managed using multimodal imaging. In each instance, the location of the buckled probe was confirmed with bedside imaging. Subsequently, the patient was taken to the interventional suite for advancement of the probe to the stomach under fluoroscopic guidance. Finally, the buckled TEE probe was straightened and removed successfully from the patient without difficulty. DISCUSSION/CONCLUSIONS:Early recognition of buckled TEE probes and employment of a structured, algorithmic management approach are essential to optimizing outcomes and preventing associated morbidity and mortality. TAKE HOME MESSAGES/CONCLUSIONS:Buckling of the TEE probe requires a high index of suspicion and prompt diagnosis to prevent catastrophic complications such as esophageal perforation. Advancement of the TEE probe in the stomach under fluoroscopic guidance facilitates straightening and removal of the probe without the risk of esophageal perforation.

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.

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.

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: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.

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.