This work dealt with the assessment of a computational tool to estimate the electrical activation in the left ventricle focusing on the latest electrically activated segment (LEAS) in patients with left bundle branch block and possible myocardial fibrosis. We considered the Eikonal-diffusion equation and to recover the electrical activation maps in the myocardium. The model was calibrated by using activation times acquired in the coronary sinus (CS) branches or in the CS solely with an electroanatomic mapping system (EAMS) during cardiac resynchronization therapy (CRT). We applied our computational tool to ten patients founding an excellent accordance with EAMS measures; in particular, the error for LEAS location was less than 4 mm. We also calibrated our model using only information in the CS, still obtaining an excellent agreement with the measured LEAS. The proposed tool was able to accurately reproduce the electrical activation maps and in particular LEAS location in the CS branches, with an almost real-time computational effort, regardless of the presence of myocardial fibrosis, even when information only at CS was used to calibrate the model. This could be useful in the clinical practice since LEAS is often used as a target site for the left lead placement during CRT. Graphical abstract Overall picture of the computational pipeline for the estimation of LEAS

Background: Left atrial appendage occlusion is an increasingly proposed treatment for patients with atrial fibrillation and poor tolerance to anticoagulants. All endovascular devices require antithrombotic therapy. Anatomical and clinical variables predisposing to device-related thrombosis, as well as post-procedural peri-device leaks, could mandate the continuation or reintroduction of aggressive antithrombotic treatment. Because of the absence of foreign material inside the heart, epicardial appendage closure possibly does not necessitate antithrombotic therapy, but data of large series are missing. Methods: Multidisciplinary team evaluation for standalone totally thoracoscopic epicardial appendage closure was done in 180 consecutive patients with atrial fibrillation and poor tolerance to antithrombotic therapy. One hundred and fifty-two patients consented (male 66.1%, mean age 76.1 ± 7.4, CHA₂DS₂VASc mean 5.3 ± 1.6, HASBLED mean 3.8 ± 1.1). Indications were cerebral hemorrhage (48%), gastro-intestinal bleeding (33.3%), and other bleeding (20.7%). No antithrombotic therapy was prescribed from the day of surgery to the latest follow up. Results: Procedural success was 98.7%. At a mean follow up of 38.2 ± 18.8 months, cardioembolic and bleeding events were 1.3% and 0.6%, respectively. Among patients with a history of blood transfusions (41.1%), none needed further transfusions or treatment post procedure. Conclusion: Epicardial appendage occlusion without any antithrombotic therapy appears to be safe and effective. This strategy could be advised when minimization of bleeding risk concomitant to stroke prevention is needed.

Atrial fibrillation is the most common sustained cardiac arrhythmia with a significant impact on quality of life in terms of symptoms and reduction of functional status. Also, it is associated with an increased risk of mortality, stroke, and peripheral embolism. Catheter ablation for atrial fibrillation has become a well-established treatment, improving arrhythmia outcomes without increasing the risk of serious adverse events compared to antiarrhythmic drug therapy. The field has undergone significant advancements in recent years, yet pulmonary vein isolation continues to be the cornerstone of any atrial fibrillation ablation procedure. The purpose of this review is to provide an overview of the current techniques, emerging technologies, and future directions.

Background: Gastrointestinal bleeding in patients with atrial fibrillation is an indication for left appendage occlusion. All endovascular devices mandate antithrombotic therapies: rebleeding risk remains an issue. To date, there are no reports on gastrointestinal rebleeding and stroke prevention by left appendage occlusion without any antithrombotic therapy in this category of patients. Methods: A total of 129 patients (male 85, mean age 76.6 ± 7.1, CHA₂DS₂Vasc 3.8 ± 1.5, HASBLED 3.3 ± 1.0; upper GI bleeding 10%, lower GI bleeding 86%, obscure occult 4.6%, on NOACS full dose 77.5%, NOACs reduced dose 13.1%, on anti-vitamin K 9.3%) with atrial fibrillation and history of repetitive gastrointestinal bleeding from ten centers underwent standalone thoracoscopic epicardial appendage closure without antithrombotic therapy for the entire follow up. Results: The observed bleeding rate was 0.91 events per year, equivalent to a relative risk of RR = 0.17 (p = 0.02) and a relative risk reduction (RRR) of 83%. The observed relative risk of stroke was 0.91 events per year, with a relative risk of RR = 0.19 (p = 0.03) and a relative risk reduction (RRR) of 81%. Conclusion: Standalone epicardial appendage occlusion without antithrombotic therapy in patients with repetitive gastrointestinal bleeding is safe and promising when rebleeding and stroke risk reduction need to be optimized.