Abstract
Atrial septal defect and patent foramen ovale are common congenital heart defects in adults, often treated with atrial septal occluders (ASOs) via percutaneous closure. Transseptal puncture (TSP) for left atrial interventions in patients with ASOs presents procedural challenges, requiring detailed pre-procedural planning and imaging. Transoesophageal echocardiography and cardiac CT help identify optimal puncture sites, either through the native septum or across the ASO. Advanced techniques, such as balloon-assisted tracking and radiofrequency energy delivery, aid in navigating the device. TSP is frequently performed for procedures such as pulmonary vein isolation, left atrial appendage occlusion, and mitral valve interventions. While generally safe and effective, TSP can lead to complications including residual shunting and device deformation, or procedural delays. Specialised expertise and multimodality imaging are crucial for optimising success and minimising risks. This review outlines TSP techniques, clinical applications and strategies for navigating ASOs during left atrial interventions.