Anatomical basis of minimally invasive epicardial ablation of atrial fibrillation

Minimally invasive atrial fibrillation surgery (MIAFS) has become a well established and increasingly used option for managing patients with stand-alone arrhythmia. Pulmonary veins (PVs) isolation continues to be the cornerstone of ablation strategies. Indeed, in most cases, atrial fibrillation (AF) is triggered in or near the PVs. Nevertheless, ectopic beats initiating AF may occasionally arise from non-PV foci. The knowledge of the anatomy and underlying morphology of PVs and non-PV foci is essential for cardiac surgeons treating AF patients with epicardial minimally invasive procedures. The anatomical structures relevant to the pathogenesis and the epicardial treatment of AF include the PVs, the pericardial space, the pericardial sinuses, the phrenic nerve, the left atrium, the retro-atrial and caval ganglionated plexuses, the ligament of Marshall, the caval veins and the left atrial appendage. In this review, we briefly describe the basic anatomy of these structures and discuss their specific correlations for cardiac surgeons interested in performing MIAFS.