The submitted medical record must support the use of the selected ICD-10-CM code(s). Q21.12 Patent foramen ovale - ICD-10-CM Diagnosis Codes.Used for patent foramen ovale (PFO) which is a normal variant and for "ruleout" congenital heart disease (CHD). Congenital malformations of the circulatory system (Q20-Q28). Cardiovascular System - Abnormalities. CPB 0267 - Intensive Cardiac Rehabilitation Programs. CPB 0267 - Intensive Cardiac Rehabilitation Programs. Patent foramen ovale (PFO) is a hole between the left and right atria (upper chambers) of the heart. This hole exists in everyone before birth.