Patent foramen ovale. Persistent foramen ovale.Q21.12 Patent foramen ovale - ICD-10-CM Diagnosis Codes. Patent foramen ovale (PFO) is a congenital cardiac lesion which is generally asymptomatic and affects up to a quarter of the population. Q21.10, Atrial septal defect, unspecified. Q21.11, Secundum atrial septal defect. Q21.13, Coronary sinus atrial septal defect. – Patent foramen ovale. – Patent ductus arteriosus. Patent foramen ovale (PFO) or hole in the heart, affects millions of people and can cause a stroke.