A Sphincter-like Function of Pulmonary Vein Ostia in Normal and Atrial Fibrillation Subjects

Background: Early anatomical study suggested that the pulmonary vein (PVs) junction may have putative sphincter-like activity. The aim of this study was to evaluate this activity in normal and paroxysmal/persistent atrial fibrillation subjects. Methods: The Cardiac Computed Tomography (CCT) scans of 45 subjects [15 normal controls, 15 patients with paroxysmal atrial fibrillation (PAR-AF), and 15 with persistent AF (PER-AF)] were retrospectively analyzed. All subjects were in sinus rhythm during the CCT scan. A 3D anatomical model was developed, enabling us to identify the PV ostia and to measure their area 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 the control in all PVs (LSPV (p < 0.001), RSPV (p < 0.001), RIPV (p = 0.037), and LIPV (p < 0.001)). Conclusions: This sphincter-like activity, most prominent in superior PVs, is progressively impaired in patients with paroxysmal and persistent AF.