BACKGROUND: Epicardial access (EA) is an essential tool for ablation of certain arrhythmias, but conventional techniques carry inherent risks. Carbon dioxide (CO(2)) insufflation in the pericardium through the coronary sinus aims to facilitate EA but is time-consuming and not widely used. Transatrial pericardial insufflation of CO(2) (TAPI-CO(2)) offers a simplified alternative, underexplored in electrophysiology procedures. OBJECTIVE: This study aimed to evaluate the efficacy and safety of TAPI-CO(2) for EA in electrophysiology procedures. METHODS: This retrospective study included all patients undergoing EA with TAPI-CO(2) at a tertiary care center between December 2020 and November 2024. The procedure involved intentional right atrial appendage perforation for CO(2) insufflation, followed by subxiphoid puncture for EA. Success rates, procedural characteristics, and complications were assessed. RESULTS: Fifteen patients (6 with atrial arrhythmias and 9 with ventricular arrhythmias) were included. TAPI-CO(2) was successfully performed in 14 patients (93.3%), and subxiphoid EA was achieved in 13 (86.7%). There were major adhesions in 2 patients (13.3%). No significant bleeding was observed after right atrial appendage perforation. One patient (6.7%) had delayed pericardial effusion related to TAPI-CO(2). No patient required surgery. Median procedural duration was 265 minutes (interquartile range, 190-288 minutes), and fluoroscopy time was 28 minutes (interquartile range, 24-32 minutes). CONCLUSION: TAPI-CO(2) is a feasible, efficient, and relatively safe technique for facilitating EA. It provides a simplified alternative to CO(2) insufflation through the coronary sinus. Further studies are needed to confirm these results and to identify the populations of patients that would benefit most from this technique.< Réduire