Transoesophageal echocardiography as complementary imaging during pulsed field ablation of atrial fibrillation: a practical step-by-step approach

Aims: Transoesophageal echocardiography (TOE) provides real-time soft-tissue anatomical information during pulsed field ablation (PFA) of atrial fibrillation. This focused technical report describes a standardized workflow in which TOE complements, rather than replaces, fluoroscopic, and angiographic guidance throughout the procedure. Technique: The workflow is organized into four consecutive phases: pre-procedural assessment, transseptal puncture, ablation-catheter configuration and positioning at the pulmonary vein ostia, and post-procedural assessment. Pre-procedural TOE focuses on exclusion of left atrial appendage thrombus, definition of pulmonary vein anatomy, assessment of the interatrial septum, and baseline evaluation for pericardial effusion. During transseptal access, orthogonal bicaval and short-axis views support puncture-site selection and continuous visualization of septal tenting, while fluoroscopy remains integral to guidewire and transseptal-system manipulation. During ablation, TOE complements fluoroscopic/angiographic guidance by depicting catheter configuration and its relationship with the pulmonary vein ostia and adjacent soft-tissue structures. At procedure completion, TOE is used to assess the iatrogenic interatrial septal defect and to exclude new pericardial effusion. Conclusion: TOE should be considered a complementary imaging modality during fluoroscopy- and angiography-guided PFA rather than a replacement for these techniques. Its principal contribution is real-time visualization of soft-tissue anatomy, transseptal puncture, catheter-tissue relationships, and immediate post-procedural complications. Prospective studies are required to quantify its incremental clinical value.