Is Patent Foramen Ovale & ASD (Atrial Septal Defect) The Same & Does PFO Cause Arrhythmia?

Both PFO and ASD are holes in the wall tissue of the heart however the cause of the condition is different.¹

PFO is a small hole with a few complications where the atrial septal defect is a larger hole between the left and right upper chambers called the septum and is more likely to cause problems. ^2.

Patent foramen ovale is a congenital heart disease-causing atrial arrhythmia to increase with increasing age to up to 38% typically in patients aged 50 years and above.^{3, 4}

When the blood circulates in the upper chambers of the heart, it becomes enlarged and grow weaker. Furthermore, pressure levels continue to increase resulting in pulmonary hypertension majorly due to atrial septal defects. The cause of PFO and ASD vary in nature. Small defects close during infancy or early childhood and never causes problems. The frequency is 1.6 percent in 1000 newborns.

Larger holes may cause complications such as increased pulmonary artery pressure, reduced exercise tolerance, and atrial fibrillation.¹

Patent foramen ovale on the other hand is a flap-like small opening between the right and left atrium of the unborn baby failing fusion of primum and secundum atrial septa. However, the hole has a purpose because it allows the blood to bypass when the baby is in the mother’s womb and the lung isn’t functional. The PFO closes completely in more than 75% of patients with a few days/months after birth.

In most cases, the patients may or may not experience symptoms nevertheless in rare cases, it causes complications and negatively impacts the quality of life. The frequency of patent foramen ovale 20-34% of the adult population and may permit paradoxical embolus.²

PFO is a congenital heart disease requiring repair when complications arise. However operative correction of PFO leads to atrial tachyarrhythmias. Atrial arrhythmias are known to be associated with atrial septal defects, so surgical closure can close atrial arrhythmias but in rare cases, it can induce new arrhythmias.

Atrial arrhythmia also called supraventricular arrhythmia caused by one or more rapid circuits in the atrium and a source of significant morbidity and mortality. Although patent foramen ovale is not directly linked to the onset of atrial arrhythmias yet there is some evidence that associates PFO with vulnerability to arrhythmias.

Certain clinical studies demonstrate cardiac surgical intervention can result in a predisposition for atrial arrhythmias in patients with PFOs. However surgical manipulations may still lead to postoperative atrial arrhythmias.

A study was conducted on PFO who underwent percutaneous closure between the years 2002 and 2007. The study showed that percutaneous closure has gained acceptability as a safe and effective therapy for patients and provides a resolution of pre-existing atrial arrhythmias and the occurrence of new post closure.^{3, 4}

A hole in the heart is always serious however a vast majority of individuals experience a few or no symptoms. For individuals who experience symptoms undergo treatment through a small invasive procedure to repair the issue.

Patent Foramen Ovale (PFO) and Atrial Septal Defect (ASD) are both holes in the walls of the tissue of the heart. ASD is present at the time of birth and resolves on its own. But larger holes can cause complications because it allows the blood to traverse between the major arteries resulting in the enlargement of the heart.

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