Patent foramen ovale

This code represents a patent foramen ovale (PFO), which is a persistent opening between the right and left atria of the heart that failed to close naturally after birth. While a normal fetal structure, its persistence in adults can sometimes be associated with various clinical conditions.

Use this code when documentation explicitly states a diagnosis of patent foramen ovale. This diagnosis is typically established through echocardiography (e.g., transthoracic or transesophageal echocardiogram with bubble study) or cardiac catheterization. It is often an incidental finding but may be documented in the context of cryptogenic stroke, migraine with aura, or decompression sickness.

• Do not confuse with atrial septal defect (ASD); a PFO is a flap-like opening, not a true septal defect with missing tissue.
• Code only when the PFO is specifically documented as a diagnosis, not merely as an anatomical finding without clinical significance.
• If the PFO is associated with a specific complication (e.g., stroke), sequence the complication first, followed by the PFO.