Q21.12 Patent foramen ovale - ICD-10-CM Diagnosis Codes. Q21.10, Atrial septal defect, unspecified.Q21.11, Secundum atrial septal defect. Patent foramen ovale. Persistent foramen ovale. Used for patent foramen ovale (PFO) which is a normal variant and for "ruleout" congenital heart disease (CHD). If you need help completing this form, please contact DSPD at 1-844-ASK-DSPD (1-844-275-3773) from a.m. An atrial septal defect repair or closure device or a patent foramen ovale repair or closure device is present. An atrial septal defect repair or closure device or a patent foramen ovale repair or closure device is present. Patent foramen ovale (PFO) or hole in the heart, affects millions of people and can cause a stroke.