Anastasios Chatziantoniou

Background: Premature ventricular contractions (PVCs) are common arrhythmias associated with symptoms such as fatigue and, in severe cases, PVC-induced cardiomyopathy. Catheter ablation (CA) is a primary treatment for symptomatic PVCs, particularly when pharmacological therapies fail or are undesired. While improvements in: quality-of-life following ablation are documented, its impact on functional capacity remains underexplored. Objectives: This study evaluated the impact of CA on functional capacity and cardiac stress markers in patients with symptomatic PVCs using cardiopulmonary exercise testing (CPET) and NT-proBNP levels. Methods: A total of 30 patients underwent successful PVC ablation and completed baseline and follow-up CPET evaluations under the Bruce protocol. PVC burden, left ventricular ejection fraction (LVEF), NT-proBNP levels, and CPET parameters, including VO₂ max, METS, ventilatory efficiency, and anaerobic threshold (AT), were analyzed pre- and post-ablation. Results: PVC burden significantly decreased post-ablation (23,509.3 ± 10,700.47 to 1759 ± 1659.15, p < 0.001). CPET revealed improved functional capacity, with VO₂ max increasing from 24.97 ± 4.16 mL/kg/min to 26.02 ± 4.34 mL/kg/min (p = 0.0096) and METS from 7.16 ± 1.17 to 7.48 ± 1.24 (p = 0.0103). NT-proBNP significantly decreased (240.93 ± 156.54 pg/mL to 138.47 ± 152.91 pg/mL, p = 0.0065). LVEF and ventilatory efficiency metrics (VE/VO₂ and VE/VCO₂) remained stable. Conclusions: Catheter ablation improves functional capacity, reduces cardiac stress, and minimizes medication dependency in patients with symptomatic PVCs. These findings support the utility of ablation in enhancing aerobic capacity and overall exercise performance.

Patent ductus arteriosus (PDA) continues to be a significant finding among infants, as well as adults. What is widely considered to be a problem though, in a group of patients with congenital heart disease, it is the only lifeline. We will initially study the anatomical and biochemical mechanisms affecting the PDA. The main focus of this review is on ductal-dependent congenital heart disease and biochemical and pharmacological approaches to maintaining ductus arteriosus patency, as well as surgical and interventional options for maintaining circulation. The present review aims to highlight gaps in the knowledge regarding the multifunctional role of ductus arteriosus endothelium and possibly propose a new approach to pharmacological maintenance of ductus arteriosus patency.

Introduction: Pulsed field ablation (PFA) is a form of nonthermal energy that has been recently introduced for pulmonary vein isolation (PVI). A multi‐electrode pentaspline catheter for delivery of PFA guided by fluoroscopy has become widely available for clinical use.Methods and Results: In this study, we aimed to assess whether the addition of electroanatomical mapping (EAM) for confirmation of PVI in the acute phase can increase the efficacy of the procedure in terms of arrhythmia recurrences. A total of 51 patients with atrial fibrillation (AF) scheduled for first time PVI were included in the study. Participants were assigned to receive PVI using fluoroscopy guidance only (Fluoro‐only group: 31 patients) or additional validation with EAM (EAM group: 20 patients). Endpoints included arrhythmia recurrence and procedural characteristics. During a 11.2 ± 1.3 months follow‐up period, arrhythmia recurrences did not statistically differ between groups (16.1% vs. 20%, p .72). Procedure time was longer in the EAM group (86.5 ± 11.4 vs. 78.4 ± 9.3 min, p .008). EAM revealed 5 nonisolated PVs that were re‐ablated using the same catheter. Four patients of the cohort underwent a redo‐procedure during the follow‐up period. In all 4 cases, at least one reconnected PV was identified.Conclusion: In a cohort of patients with AF undergoing first time PVI using a pentaspline PFA catheter, PVI validation with EAM did not lead to significantly different arrhythmia recurrence rates compared to PVI without EAM. In the acute phase, the rate of nonisolated PVs was low.

The Fontan operation, the final palliative step after a series of complex operations in patients with univentricular hearts, has undergone multiple modifications throughout the last decades, with the goal of finding the method which combines the optimal hemodynamic effects of the Fontan circulation with minimal long term side effects. An understanding of the operative evolution and subsequent side effects, as well as the management thereof seems imperative. Since its inception by Francis Fontan the, now obsolete, initial atriopulmonary connection has passed through several milestones into having now reached the era of total cavopulmonary connection. However, recently published results bring to light the new option of biventricular conversion which comes to challenge the management of Fontan patients as we know it. Currently, there is no consensus as to whether to continue with palliation in this challenging group of patients or proceed with heart transplantation. In this collective review, we provide a historic overview of the Fontan evolution as well as future insights, discussing the perspectives of options for patients with failing Fontan, including the latest addition of biventricular correction.