7 Key Symptoms of Patent Foramen Ovale You Should Know

Introduction to Patent Foramen Ovale

Patent Foramen Ovale (PFO) is a common congenital heart condition that affects approximately 25% of the adult population. The foramen ovale is a small opening between the two upper chambers of the heart (atria) that is present in all fetuses during development. Normally, this opening closes shortly after birth, but in individuals with PFO, it remains open or patent throughout their lives.

While many people with a PFO heart condition never experience symptoms and live completely normal lives, others may develop complications or notice certain signs that indicate the presence of this structural abnormality. Understanding the symptoms associated with patent foramen ovale is crucial for early detection and proper management of potential complications.

In this comprehensive guide, we’ll explore the key symptoms of PFO, helping you recognize when this typically benign condition might require medical attention.

1. Stroke or Transient Ischemic Attack (TIA) in Young Adults

One of the most significant symptoms associated with patent foramen ovale is an unexplained stroke or transient ischemic attack (TIA), particularly in younger individuals without traditional risk factors for stroke. This occurs through a mechanism called paradoxical embolism.

When a blood clot forms in the venous system, it would normally travel to the lungs where it would be filtered out. However, in individuals with PFO, the clot can pass through the opening between the atria and enter the arterial circulation, potentially reaching the brain and causing a stroke.

Key characteristics include:

• Sudden weakness or numbness on one side of the body
• Difficulty speaking or understanding speech
• Vision problems in one or both eyes
• Severe headache with no known cause
• Dizziness or loss of balance

If you experience any stroke symptoms, seek immediate emergency medical care, as this is a medical emergency regardless of the underlying cause.

2. Migraine Headaches with Aura

There is a well-established connection between patent foramen ovale and migraine headaches, particularly migraines with aura. Studies have shown that individuals with PFO are more likely to experience migraines with aura compared to those without this heart condition.

The exact mechanism linking PFO and migraines is not fully understood, but researchers believe that small blood clots or chemicals passing through the foramen ovale may trigger migraine attacks by affecting blood flow or nerve function in the brain.

Migraine with aura symptoms may include:

• Visual disturbances such as flashing lights, zigzag patterns, or blind spots
• Tingling sensations or numbness in the face or extremities
• Difficulty with speech or language
• Severe, throbbing headache, typically on one side of the head
• Sensitivity to light and sound
• Nausea or vomiting

While not all individuals with PFO will experience migraines, and not all migraine sufferers have PFO, the association is strong enough that some physicians may investigate for PFO in patients with frequent migraines with aura.

3. Shortness of Breath (Dyspnea)

Some individuals with patent foramen ovale may experience unexplained shortness of breath, especially during physical activity or when changing positions. This symptom is more common in cases where the PFO is moderate to large in size, allowing significant blood flow between the atria.

The shortness of breath occurs because deoxygenated blood from the right atrium can pass through the PFO into the left atrium, mixing with oxygen-rich blood. This results in decreased oxygen levels in the blood circulating throughout the body, leading to the sensation of breathlessness.

This symptom may manifest as:

• Difficulty breathing during exercise or physical exertion
• Breathlessness when lying flat (orthopnea)
• Feeling winded after activities that previously didn’t cause problems
• Inability to take deep, satisfying breaths
• Rapid breathing or feeling like you can’t get enough air

It’s important to note that shortness of breath can be caused by many conditions, so a thorough medical evaluation is necessary to determine if PFO is the underlying cause.

4. Platypnea-Orthodeoxia Syndrome

Platypnea-orthodeoxia syndrome is a rare but distinctive symptom complex that can occur in individuals with patent foramen ovale. This condition is characterized by shortness of breath and decreased oxygen levels in the blood that worsen when standing upright and improve when lying down – the opposite of what occurs in most respiratory conditions.

This unusual pattern happens because gravitational forces and changes in heart chamber pressures when standing can increase blood flow through the PFO from right to left, resulting in more deoxygenated blood entering the systemic circulation.

Characteristics of this syndrome include:

• Shortness of breath that is worse when sitting or standing
• Improvement of breathing difficulties when lying flat
• Low oxygen saturation levels detected on pulse oximetry when upright
• Bluish discoloration of lips or fingertips (cyanosis) when standing
• Fatigue and weakness that improve with recumbent positioning

This syndrome is more commonly seen in older adults and may develop after certain anatomical changes in the heart or chest, such as after cardiac surgery or with age-related changes in heart structure.

5. Decompression Sickness in Divers

Individuals with patent foramen ovale who participate in scuba diving are at increased risk of experiencing decompression sickness, also known as “the bends.” This occurs because nitrogen bubbles that form during ascent from a dive can pass through the PFO and enter the arterial circulation, affecting various organs including the brain and spinal cord.

Normally, these nitrogen bubbles would be filtered by the lungs and expelled during breathing. However, when a PFO is present, bubbles can bypass the lungs through the cardiac shunt, leading to potentially serious neurological complications.

Symptoms of decompression sickness in PFO patients may include:

• Joint and muscle pain, particularly in the shoulders, elbows, and knees
• Numbness or tingling in the extremities
• Extreme fatigue and weakness
• Dizziness and vertigo
• Difficulty with coordination or balance
• Confusion or changes in consciousness
• Vision or hearing problems
• Chest pain or difficulty breathing

Divers with known PFO should discuss the risks with their physician and may need to take special precautions or avoid diving altogether, depending on the size of the defect and other risk factors.

6. Cyanosis or Bluish Skin Discoloration

In some cases, particularly when the patent foramen ovale is large or when there are other associated heart conditions, individuals may develop cyanosis – a bluish or purplish discoloration of the skin, lips, or nail beds. This occurs due to insufficient oxygen in the blood.

Cyanosis in PFO typically happens when significant right-to-left shunting occurs, meaning deoxygenated blood from the right side of the heart passes through the foramen ovale into the left side without being oxygenated in the lungs. This results in lower oxygen saturation levels in the blood being pumped to the body.

Signs of cyanosis may include:

• Blue or purple tinge to the lips
• Bluish discoloration under the fingernails or toenails
• Grayish or blue-tinted skin, especially noticeable in lighter-skinned individuals
• Discoloration that may worsen with physical activity or certain positions
• Cool extremities accompanying the color change

Cyanosis is more commonly associated with larger PFOs or when other heart defects are present. It requires prompt medical evaluation as it indicates significant oxygen desaturation.

7. Fatigue and Reduced Exercise Tolerance

Persistent, unexplained fatigue and decreased ability to exercise may be subtle symptoms of patent foramen ovale in some individuals. When the PFO allows deoxygenated blood to mix with oxygenated blood, the overall oxygen-carrying capacity of the blood is reduced, leading to decreased energy levels and endurance.

This symptom is often overlooked because it can be attributed to many other causes and may develop gradually over time, making it difficult to recognize. Individuals may notice they cannot exercise at the same intensity or duration as they once could without experiencing exhaustion.

This may present as:

• Feeling tired even after adequate rest and sleep
• Difficulty completing physical activities that were previously manageable
• Needing frequent breaks during exercise or daily activities
• Muscle weakness or heaviness during exertion
• Prolonged recovery time after physical activity
• General lack of energy throughout the day

While fatigue and exercise intolerance are non-specific symptoms that can indicate many different health conditions, they may warrant investigation for PFO when they occur alongside other symptoms or in the context of unexplained oxygen desaturation.

Main Causes of Patent Foramen Ovale

Understanding what causes patent foramen ovale to persist after birth is important for recognizing risk factors and potential complications. Here are the main causes and contributing factors:

Incomplete Closure After Birth

The primary cause of PFO is the failure of the foramen ovale to close completely after birth. In fetal development, this opening is necessary to allow blood to bypass the non-functioning lungs. After birth, when the baby takes their first breaths and the lungs begin functioning, pressure changes in the heart should cause this opening to seal shut. In individuals with PFO, this natural closure process is incomplete.

Genetic Factors

There appears to be a genetic component to patent foramen ovale, as it tends to run in families. Research suggests that certain genetic variations may affect the development and closure of the foramen ovale, making some individuals more susceptible to having a persistent opening.

Anatomical Variations

Some individuals may have anatomical variations in the structure of the atrial septum (the wall between the two upper chambers of the heart) that prevent complete closure. The size and shape of the septum primum and septum secundum – the two tissue flaps that should seal the foramen ovale – can vary among individuals.

Pressure Differences Between Atria

Normally, after birth, the pressure in the left atrium becomes higher than in the right atrium, which helps push the septum primum against the septum secundum to seal the foramen ovale. In some cases, abnormal pressure relationships between the atria may prevent this seal from forming completely.

Associated Congenital Heart Conditions

PFO may occur more frequently in individuals with other congenital heart defects or structural abnormalities. The presence of other heart conditions may affect the normal closure process or maintain abnormal pressure gradients that keep the foramen ovale patent.

Prematurity

Premature infants may be more likely to have a patent foramen ovale, although in many cases it will eventually close during infancy or early childhood as the heart continues to develop and mature.

Frequently Asked Questions

Is patent foramen ovale dangerous?

For most people, PFO is not dangerous and causes no symptoms or health problems throughout their lifetime. However, it can increase the risk of certain complications such as stroke, particularly in younger adults, and migraines with aura. The level of risk depends on the size of the opening and individual factors. Most people with PFO live normal, healthy lives without requiring any treatment.

Can PFO close on its own in adults?

While the foramen ovale typically closes within the first year of life, spontaneous closure in adults is rare. Most PFOs that persist beyond early childhood will remain open throughout adulthood. However, the size of the opening may vary over time, and in some cases, the flap-like valve covering the opening may become more effective at preventing blood flow between the atria.

How common is patent foramen ovale?

Patent foramen ovale is very common, affecting approximately 25% of the general adult population, or about one in four people. Many individuals are never aware they have it because it typically doesn’t cause symptoms. It is found equally in men and women and across all ethnic groups.

Do I need to avoid certain activities if I have PFO?

Most people with PFO can participate in normal activities without restrictions. However, individuals who engage in scuba diving may need to take special precautions or avoid diving, as PFO increases the risk of decompression sickness. If you have experienced stroke or TIA related to PFO, your doctor may provide specific activity recommendations. Always consult with your healthcare provider about your individual situation.

How is patent foramen ovale diagnosed?

PFO is typically diagnosed using echocardiography, particularly a transesophageal echocardiogram (TEE), which provides detailed images of the heart structures. A bubble study may be performed during the echocardiogram, where saline with tiny bubbles is injected into a vein while the heart is imaged. If bubbles appear in the left atrium, it indicates the presence of a PFO. The test may be performed while the patient performs a Valsalva maneuver (bearing down) to increase the likelihood of detecting the shunt.

Can PFO cause heart failure?

Patent foramen ovale alone does not typically cause heart failure. The opening is usually small and doesn’t significantly affect heart function. However, in rare cases with very large PFOs or when combined with other heart conditions, it may contribute to cardiac complications. Most people with PFO have normal heart function and do not develop heart failure as a result of this condition.

Should I tell my doctor if I suspect I have PFO symptoms?

Yes, you should always discuss any concerning symptoms with your healthcare provider, especially if you experience stroke-like symptoms, severe migraines with aura, unexplained shortness of breath, or episodes of decompression sickness while diving. Your doctor can determine whether further evaluation for PFO is appropriate based on your symptoms and medical history. Early detection can help prevent complications and guide appropriate management if needed.

Is there a connection between PFO and COVID-19?

Some research has suggested that individuals with PFO who contract COVID-19 may have a slightly increased risk of blood clots and stroke, as COVID-19 can increase blood clotting throughout the body. However, more research is needed to fully understand this relationship. If you have a known PFO and contract COVID-19 or any serious illness, inform your healthcare providers so they can monitor you appropriately.

References:

• Mayo Clinic – Patent Foramen Ovale
• American Heart Association – Patent Foramen Ovale
• National Heart, Lung, and Blood Institute – Patent Foramen Ovale
• StatPearls – Patent Foramen Ovale
• Johns Hopkins Medicine – Patent Foramen Ovale