Patent Foramen Ovale

A Patent Foramen Ovale (PFO) is a small, flap-like opening between the right and left atria of the heart that fails to close after birth. It's not the same as an Atrial Septal Defect (ASD), though they're related.

🫀 What Is the Foramen Ovale?

• In fetal circulation, the foramen ovale is a normal opening that lets blood bypass the non-functioning fetal lungs.
• After birth, when the baby starts breathing, this opening usually closes naturally as pressure in the left atrium increases.

When it doesn’t fully seal, it’s called a Patent Foramen Ovale (PFO).

🧠 How Common Is It?

• Found in about 25% of the general population
• Usually harmless and asymptomatic
• Often discovered incidentally during imaging or workup for stroke

🧪 Symptoms & When It Matters

Most people with PFO have no issues. But it can become significant in certain situations, such as:

• Cryptogenic stroke (stroke of unknown cause)
  A blood clot can pass from the right atrium to the left through the PFO and travel to the brain (paradoxical embolism).
• Migraine with aura (possible association)
• Decompression sickness in divers (nitrogen bubbles can bypass lungs)
• Platypnea-orthodeoxia syndrome (rare condition where oxygen levels drop when upright)
• Shortness of breath and Hypoxia

Certain patients with large PFOs with significant right to left shunting can present with shortness of breath and hypoxia. However, other co-existing conditions needs to be ruled out.

🩻 Diagnosis

• Echocardiogram with bubble study (contrast echo): Bubbles in the bloodstream can show up crossing the atrial septum.
• Transesophageal echocardiogram (TEE) – more accurate than transthoracic

🛠️ Treatment

Depends on the situation:

1. No treatment if no symptoms or complications
2. Antiplatelet therapy (like aspirin) or anticoagulants if there's been a stroke
3. PFO closure via catheter-based procedure in:
• Select patients with cryptogenic stroke (especially younger individuals)
• Divers or others at high risk of embolism
• Platypnea-orthodeoxia syndrome
• Selected patients with shortness of breath and hypoxemia with a large PFO with significant right to left shunting can be considered for closure after a thorough evaluation and ruling out other disease process

⚖️ PFO vs ASD