Epicardial and endocardial left atrial appendage occlusion (LAAO) is commonly performed for stroke prevention for atrial fibrillation (AF) patients at increased risk for stroke who cannot tolerate long-term oral anticoagulation. However, there is limited data on the outcomes of unsuccessful LAAO procedures. This study aims to assess the incidence and outcomes of unsuccessful LAAO procedures. A retrospective analysis was performed on patients undergoing LAAO at our institution from 2020 to 2023. The primary endpoint was a failure to deploy the LAAO device, which was defined as unsuccessful device implantation (UDI). A total of 411 patients underwent LAAO (Lariat = 6.8

The Heart Rhythm Society (HRS) Scientific Documents Pathway was established to support the development of high-quality, evidence-informed scientific statements that advance the field of electrophysiology through the synthesis and communication of foundational knowledge, translational insights, and emerging trends. Unlike clinical practice guidelines, scientific documents are not designed to offer practice recommendations. Instead, they provide a framework for understanding scientific domains that impact the arrhythmia care community. The Scientific Documents Committee oversees the proposal review, development, and approval of these documents, ensuring transparency, balance, and methodological consistency. This executive summary outlines the core components of the Scientific Documents Methodology Manual, including document types, committee structure, proposal and review processes, writing committee expectations, conflict of interest management, and publication requirements. The manual is intended to support the HRS community, authors, and partners in understanding the process by which these documents are developed and how they serve the Society’s strategic goals.

BACKGROUND:Left atrial appendage closure (LAAC) is increasingly used for stroke prevention; however, left atrial appendage (LAA) anatomy may pose significant challenges. CASE SUMMARY:A 67-year-old man with paroxysmal atrial fibrillation, CHA2DS2-VASc Score of 3, and recurrent falls was referred for LAAC. Owing to challenging anatomy noted during preoperative imaging, epicardial access was obtained at procedure onset. Following multiple unsuccessful endocardial attempts, LAAC was successfully achieved by an epicardial device. DISCUSSION:Preprocedural imaging can identify challenging LAA anatomy and assist in procedural planning. In patients with challenging LAA anatomy, obtaining epicardial access up front before endocardial closure attempts offers an additional immediate option in case of failure. This case highlights the importance and use of both endocardial and epicardial LAAC strategies for a comprehensive LAAC program. TAKE-HOME MESSAGE:We demonstrate that a methodological approach with preprocedural LAA imaging and endocardial and epicardial LAAC strategies results in successful clinical outcomes.

BACKGROUND:Early evidence showed reduced complications with pulsed field ablation (PFA), but non-target tissue collateral damage created by electroporation effects is poorly understood and may significantly differ between systems. OBJECTIVES:In this study, the authors evaluated the collateral effects of PFA. METHODS:NEMESIS-PFA is a multicenter, observational registry of patients who underwent AF ablation from March 2024 onwards with any approved PFA systems-either a circular multielectrode array, spherical, pentaspline, or variable loop catheter-or radiofrequency ablation (RFA). We assessed procedural characteristics, biomarkers for myocardial injury, hemolytic anemia, and renal function, and left atrial function in select patients. RESULTS:A total of 871 patients, aged 68.9 ± 10.9 years and male (70.8%), with paroxysmal atrial fibrillation (59.4%), and CHA2DS2VASC of 3.3 ± 1.3 were included. Of these, 87.1% (n = 773) underwent PFA with a pentaspline (70.9%), circular multielectrode (14.1%), spherical (12.4%), and variable loop (2.3%) catheter. Significant postprocedural change in certain biomarkers such as troponin (13,551.0 vs 127.5 ng/dL; P < 0.001), lactate dehydrogenase (107.5 vs 26.5 IU/L; P < 0.001), and haptoglobin (-102.0 vs -33.5 mg/dL; P < 0.001) were detected following the PFA procedures compared with RFA, and the change was dose-dependent. There were also significant differences in biomarkers across PFA systems. Lastly, there was a significant change in left atrial ejection fraction (-20.0% vs. -5.0%, P < 0.001) in PFA vs RFA. CONCLUSIONS:Current PFA technologies are associated with worse troponin leak, hemolysis, and renal dysfunction than RFA. As PFA becomes mainstream, future studies appraising these effects and understanding the short term and long-term implications are needed.