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

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.

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.

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)).

This sphincter-like activity, most prominent in superior PVs, is progressively impaired in patients with paroxysmal and persistent AF.