A Sphincter-Like Function of Pulmonary Veins Ostia in Normal and Atrial Fibrillation Subjects

Background: early anatomical study suggested that pulmonary veins (PVs) junction may have a putative sphincter-like activity preventing backward flow during left atrial contraction Methods: the cardiac tomography (CT) scan of 45 subjects [15 normal controls, 15 patients with paroxysmal atrial fibrillation (PAR-AF) and 15 with persistent AF (PER-AF)] were retrospectively analysed. A 3D anatomical model was developed enabling to identify the PVs ostia and to measure their dynamic changes during the cardiac cycle. Results: The area changes in the superior PVs within the three groups were significantly higher compared to the inferior (control p= 0.007, PAR-AF p=0.0003, PER-AF p=0.04). Moreover, these variations were significantly reduced in PAR-AF and PER-AF compared to control in all PVs ( LSPV (p< 0.001), RSPV (p< 0.001), RIPV (p=0.037) and LIPV ( p< 0.001). Conclusion: the use of this 3D LA anatomical reconstruction derived from CT scan acquisition allows an accurate visualization of the morphology of the PVs, an identification the atrial-venous junction and the evaluation of the dynamic variation of the PVs ostia during the entire cardiac cycle. This sphincter-like activity seems to be particularly evident at the superior compared to the inferior PVs junction and is partially and progressively impaired in AF patients.