Overview of Left Atrial Enlargement

The left atrium is located in the upper left part of the heart. It is one of four chambers in the heart. Numerous heart problems can cause the left atrium to swell, which causes left atrial enlargement (LAE).

Health conditions associated with the enlargement of the left atrium include high blood pressure, atrial fibrillation, mitral valve dysfunction, and left ventricle problems.

The prevalence of LAE in the United States is 6.43 percent in people over the age of 35. For many people, an enlarged atrium does not cause any symptoms. When someone does experience symptoms, however, they may include: 

• Shortness of breath and/or breathlessness
• Fatigue
• Loss of appetite
• Nausea
• Palpitations (irregular or rapid heartbeats)
• Edema
• Weight gain
• Dizziness and lightheadedness
• Fainting
• Chest Pain

Left atrial enlargement is influenced by certain risk factors affecting the size of the left atrium.

Normal aging isn’t a cause of LAE; however, changes to the body as a person ages can influence the size of the left atrium. It may become bigger over time. In relation to sex, men tend to have larger left atriums than women do. Finally, the larger a person’s body is, the larger their left atrium will be. 

High Blood Pressure 

High blood pressure is common in people with LAE. One review in the American Journal of Hypertension of 15 studies over a period of 12 years found that LAE was present in 16 to 83 percent of people with high blood pressure. 

Atrial Fibrillation

Atrial Fibrillation (A-Fib) is a problem that causes arrhythmia, or irregular heartbeats. This causes the two upper chambers of the heart to beat differently than the two lower chambers.

Persistent A-Fib may eventually enlarge the left atrium. A-Fib can either be permanent or temporary, but it is unknown whether it is a cause or complication of LAE. 

Mitral Valve Dysfunction 

Some conditions associated with the mitral valve may contribute to LAE. The mitral valve is the valve with two flaps in the heart, lying between the left atrium and the left ventricle. Mitral stenosis causes the mitral valve to narrow and makes it harder for the left ventricle to be filled. 

Mitral regurgitation, on the other hand, causes blood to leak from the left ventricle into the left atrium. Both of these conditions make it difficult for the left atrium to pump blood to the left ventricle, resulting in increased pressure in the left atrium—this eventually causes enlargement. 

Left Ventricle Problems 

Problems with the left ventricle put pressure on the left atrium, leading to the enlargement of the left atrium. 

A diagnosis of LAE can be made by looking at the heart with an echocardiogram. This test uses ultrasound to take pictures of the heart. 

The test is performed with the person lying down on a table and the technician attaching metal electrodes to the person’s chest. The technician will then pass a small sound wave probe over the chest. These sound waves bounce off the heart and echo back to the probe, producing images. The echocardiogram is a safe procedure that causes no pain or harm and has no side effects. 

Other tests that may be used in the diagnosis of LAE include magnetic resonance imaging (MRI) and computed tomography (CT) scans. These tests make measures of the left atrium to determine its size and if it is enlarged in comparison to its normal size.

Treatment of left atrial enlargement focuses on identifying and treating the cause of it. 

High Blood Pressure Treatment

High blood pressure is treated with medications and management of unhealthy habits, including a healthy diet low in salt. It also involves limiting alcohol, exercising, managing stress, and not smoking.  

Mitral Stenosis Treatment

Treatment options for mitral stenosis include diuretics to reduce fluid, blood thinners to prevent clots, and anti-arrhythmic drugs to manage irregular heartbeat. Additionally, surgery can repair or replace the mitral valve.

Mitral Regurgitation Treatment

Treatment for mitral regurgitation includes medications to reduce the risk of blood clots. Much like mitral stenosis, surgery can repair the problem.

Left Ventricle Dysfunction Treatment

Beta-blockers and ACE inhibitor drugs are used to treat left ventricle dysfunction. This condition can also be treated with an implantable cardiovascular defibrillator (ICD). An ICD is a battery-powered device placed under the skin with thin wires connecting to the heart. It will track a person’s heart rate and uses electric shocks to correct any dangerous rhythms.

If left untreated or if not properly treated, LAE is associated with blood clots, stroke, heart failure, and other heart problems. Therefore, it is important for people diagnosed with LAE or its associated conditions to be treated and have their heart health regularly monitored.

A Word From Verywell

Most people with left atrial enlargement have no symptoms. Having LAE is generally a sign of an underlying heart condition. Treatment for conditions associated with LAE vary from lifestyle changes to medication and surgery.  LAE can also put people at risk for additional heart problems, so it's important to keep blood pressure and heart rhythms under control. If you have a family history of heart problems, be sure to tell your doctor. This way, your heart health can be carefully watched.