Abstract

Patent foramen ovale and atrial septal defects: A focused overview

Author(s): Joseph Elias1, Karl Abou Zeid2, Chloe Kharsa1, Rody G. Bou Chaaya2, Joe Aoun1*

The foramen ovale is a key fetal cardiac structure enabling oxygenated blood flow from the right to the left atrium, bypassing the non-functional fetal lungs. Postnatally, this opening typically closes due to increased left-sided atrial pressure. However, the closure remains incomplete in approximately 25%-30% of adults, resulting in a Patent Foramen Ovale (PFO), which can have significant clinical implications. PFO has been associated with cryptogenic strokes, migraines, Platypnea-Orthodeoxia Syndrome (POS) and decompression sickness. In cryptogenic strokes, PFO serves as a potential pathway for paradoxical embolism. Migraine, particularly with aura, has shown a correlation with PFO, although trials like MIST and PREMIUM did not support routine PFO closure for migraines.

Diagnosis of PFO includes Transthoracic (TTE) and Transesophageal Echocardiography (TEE), with TEE being the gold standard due to its high sensitivity and specificity. Management strategies for PFO-associated strokes involve medical therapy (antiplatelets or anticoagulants) and transcatheter closure. Trials such as CLOSURE, RESPECT and DEFENSE-PFO demonstrated variable outcomes, with newer guidelines advocating closure in high-risk cases.

Atrial Septal Defects (ASDs) manifest later in life with potential complications like atrial arrhythmias and Eisenmenger syndrome. Diagnosis primarily relies on echocardiography, with cardiac Magnetic Resonance Imaging (MRI) and Computed Tomography (CT) providing further assessment. Management depends on defect type and size, with percutaneous closure preferred for ostium secundum defects. Surgical repair is reserved for larger defects or associated structural abnormalities. Complications of percutaneous procedures include arrhythmias and device embolization. Overall, optimal patient selection and multidisciplinary collaboration are essential to achieving positive outcomes in managing PFO and ASD.