The Possible Causes of Right Atrial Enlargement

Having a right atrial enlargement (RAE) doesn’t always produce symptoms, but it is highly associated with other conditions. What are the health problems related to RAE? Find out here.

What is Right Atrial Enlargement? 

To understand what RAE is, we need to review the basic anatomy of the heart.

Our heart has four chambers: right atrium, right ventricle, left atrium, and left ventricle.

The right atrium receives oxygen-poor blood from the body and pumps it to the right ventricle, which then pumps the blood to the lungs to collect oxygen. The left atrium receives the oxygen-rich blood from the lungs, pumps it to the left ventricle, and then pumps it to the rest of the body.

Now, right atrial enlargement indicates that the right atrium is bigger than normal. It is seen through radiographs or cardioangiography tests. However, RAE may be a little difficult to observe because its position overlaps with the right ventricle. In many cases, people with RAE also have right ventricular enlargement.  

Cardiologists can also suspect right atrial enlargement through electrocardiogram (ECG) results. 

RAE is a type of cardiomegaly (enlarged heart). It is not a disease, but it is often a sign of another health problem.

Conditions Associated With Right Atrial Enlargement

The following conditions show a strong association with right atrial enlargement.

Ebstein’s Anomaly of the Tricuspid Valve

The tricuspid valve is found between the right atrium and the right ventricle. Once the right atrium pumps blood to the right ventricle, the tricuspid valve closes, ensuring the blood will not go up to the right atrium again.

If you have Ebstein’s anomaly, though, the tricuspid valve doesn’t fully close, resulting in a backflow. Due to added blood volume, right atrial enlargement may occur, and complications, such as heart failure, may arise.

Right Ventricular Hypertrophy 

In many cases, patients with right ventricular hypertrophy (enlargement of the right ventricle) also exhibit RAE.

According to some reports, right ventricular hypertrophy occurring in patients with pulmonary disease may indicate cor pulmonale or right-sided heart failure.

Pulmonary Hypertension

Pulmonary hypertension is high blood pressure in the pulmonary arteries, the vessels supplying blood to the lungs.

The walls of the pulmonary arteries are often thick and stiff, which don’t allow much blood to flow. As a result, the right side of the heart develops difficulty in pumping blood to the lungs.

People with pulmonary hypertension often present with right atrial enlargement and right ventricular hypertrophy.

Pulmonary Diseases

Pulmonary diseases, like chronic obstructive pulmonary disease, are highly associated with RAE.

With COPD, the lungs struggle to deliver adequate oxygen, significantly adding to the heart’s workload. Additionally, COPD can lead to pulmonary hypertension.

Congenital Heart Disease 

Finally, congenital heart diseases, such as the tetralogy of Fallot, can also lead to right atrial enlargement.

You see, the tetralogy of Fallot is made up of four defects, some of which can affect the right atrium. In this condition, the patient has:

• A hole between the two ventricles
• Pulmonary artery stenosis, where the pulmonary valve is narrowed. Stenosis can lead to pulmonary hypertension.
• An enlarged aortic valve
• Right ventricular hypertrophy, a condition that is also associated with RAE.

Learn more about Heart Health here.