Potential causes of left atrial enlargement

Left atrial enlargement is characterized as the growth of the left atrium due to increased pressure. The left atrium is the heart chamber that takes in oxygenated blood via the lungs. The blood travels from the left atrium via the mitral valve into the left-side ventricle which is the chief pumping chamber of the heart.

The condition can range from minor, moderate or severe depending on the seriousness of the underlying ailment. Some of the conditions that can lead to left atrial enlargement include heart valve conditions, hypertension, atrial fibrillation and heart failure.

Common causes of left atrial enlargement



Heart failure arises if the heart could not effectively pump blood to the entire body.

Hypertension or high blood pressure causes the straining of the heart as it propels blood all over the body. Since the heart is comprised of elastic muscle tissue, it steadily grows while pumping against high pressure.

The left ventricle usually enlarges first. When the pressure rises in the left ventricle, the atrium steadily expands as well. Once left atrial enlargement manifests due to high blood pressure, it is linked to a higher risk for stroke and heart attack.

Heart valve disease

Issues of the heart valves can lead to left atrial enlargement such as:

  • Mitral stenosis – there is buildup of blood in the left atrium
  • Mitral regurgitation – there is leakage in the mitral valve where blood moves back into the left atrium as the left ventricle contracts
  • Aortic stenosis – the heart pumps harder against high pressure to eject blood into the aorta

Heart failure

Heart failure arises if the heart could not effectively pump blood to the entire body. If high blood pressure is not properly controlled along with coronary artery disease and abuse of alcohol and drugs, it can lead to heart failure.

Once the heart weakens progressively, blood is likely to build up in the heart and lungs which results to left atrial enlargement.

Atrial fibrillation

It is important to note that atrial fibrillation is an erratic heart rhythm that results to the irregular beating of the heart.

Normally, the atria and ventricles beat in a synchronized manner, but atrial fibrillation disrupts this process. Ailments such as heart failure and mitral stenosis that can result to left atrial enlargement often progress to atrial fibrillation.

Individuals with atrial fibrillation and left atrial enlargement can be managed using blood thinners to lower the risk for stroke.