The foramen ovale is a physiological channel in the atrial septum during the embryonic period. In most individuals, the foramen ovale closes spontaneously within the first year after birth. If it remains open beyond the age of 3, it is classified as a patent foramen ovale (PFO).
Pathological Anatomy
PFO is defined as a small slit-like opening at the site of the fossa ovalis caused by incomplete fusion of the primary and secondary septa.
Pathophysiology
PFO typically has minimal impact on cardiac hemodynamics. However, there is a strong association between PFO and cryptogenic stroke. The presence of PFO can lead to a paradoxical embolism, which may cause corresponding clinical symptoms.
Clinical Manifestations
When PFO results in significant right-to-left shunting, it may lead to cryptogenic stroke (CS) or migraines. Other potential symptoms include syncope, transient aphasia, sleep apnea, platypnea-orthodeoxia syndrome (POS), and orthopnea.
Auxiliary Examinations
Echocardiography
Transesophageal echocardiography (TEE) combined with right-heart contrast imaging and adequate provocative testing is considered the gold standard for diagnosing PFO.
Diagnosis and Differential Diagnosis
The diagnosis of PFO relies primarily on cardiac echocardiography with right-heart contrast imaging. PFO should be differentiated from small atrial septal defects.
Treatment
PFO associated with cryptogenic stroke, transient ischemic attack (TIA), or migraines should be treated. Treatment options include:
- Medical therapy: Anticoagulants or antiplatelet agents
- Catheter-based closure
- Surgical closure: In most cases, surgical repair of PFO replaced by catheter-based interventions
Prognosis
Once evidence of paradoxical embolism is identified, prompt treatment leads to a good prognosis.