Patent foramen ovale. Persistent foramen ovale.Patent foramen ovale (PFO) is a small hole between the upper right and left chambers (atria) of your heart. This hole may let blood flow between the atria. Q21.12 Patent foramen ovale - ICD-10-CM Diagnosis Codes. A condition in which the foramen ovale in the atrial septum fails to close shortly after birth. Q2113, CC, 54 codes, Coronary sinus atrial septal defect. 0.25°) and in 6 out of 10 cases the relapse was at the most 0.50. 11-10: Important Provider Notification: 835 Files and Remits. Showing complete occlusion of the PFO.