What Is Left Atrial Enlargement?

Left atrial enlargement, also known as left atrial dilation, refers to the enlargement of the left atrium, one of the four chambers of the heart. It occurs when the left atrium expands beyond its normal size, which can be a result of various underlying conditions or cardiovascular diseases. Left atrial enlargement is often an indication of an underlying health issue and may impact the heart's ability to function optimally.

In left atrial enlargement, the left atrium's walls stretch and become larger than normal. This expansion can lead to changes in the heart's electrical activity and disrupt the normal blood flow patterns within the heart. The condition is typically diagnosed using imaging tests, such as echocardiography.

If you want to gain a comprehensive understanding of left atrial enlargement, including its management, diagnosis, and potential complications, keep reading. This article will provide you with the necessary information to empower you to manage your heart health.


The human heart has four chambers: two atria (left atrium and right atrium) and two ventricles (left ventricle and right ventricle). These chambers work in tandem to facilitate the efficient flow of blood throughout the body. The left atrium, specifically, serves as a receiving chamber for oxygenated blood returning from the lungs.

Located in the upper left portion of the heart, the left atrium receives oxygen-rich blood through the pulmonary veins, which bring blood from the lungs. It acts as a reservoir, temporarily storing this oxygenated blood before it is sent to the left ventricle, which then pumps it out to supply the rest of the body.

Under normal circumstances, the left atrium maintains a specific size and shape to support its essential functions. However, certain conditions can cause the left atrium to enlarge, resulting in left atrial enlargement.

Left atrial enlargement, also known as left atrial dilation, refers to the expansion of the left atrium beyond its normal size. This enlargement can occur due to various underlying factors, such as high blood pressure and heart valve diseases. It is important to note that left atrial enlargement is often a sign of an underlying health issue rather than a standalone condition.

When the left atrium is enlarged, its walls stretch and become larger than normal. This expansion can lead to changes in the heart's electrical activity and disrupt the normal flow patterns and pressure of blood within the heart. Left atrial enlargement is typically diagnosed using imaging tests, such as echocardiography, which provide detailed images of the heart's structure and function.

Causes of left atrial enlargement

Left atrial enlargement can be caused by a variety of underlying factors, ranging from cardiovascular conditions to lifestyle choices. Let's explore some of the common causes in more detail.

High blood pressure (hypertension) 

One of the main causes of left atrial enlargement is chronic high blood pressure. When blood pressure remains elevated over an extended period, the left atrium has to work harder to pump blood into the left ventricle. This increased workload can lead to the enlargement of the atrium over time.

Heart valve disease   

Conditions affecting the heart valves can contribute to left atrial enlargement. Two common valve abnormalities include:

  • Mitral regurgitation: In this condition, the mitral valve, which separates the left atrium and the left ventricle, does not close properly. As a result, some of the blood flows back into the left atrium during each heartbeat. Over time, this regurgitation can cause the left atrium to enlarge.
  • Mitral stenosis: Here, the mitral valve becomes stiff and narrow, impeding the flow of blood from the left atrium to the left ventricle. This obstruction increases pressure within the left atrium, leading to its enlargement.

Atrial fibrillation 

Atrial fibrillation (AF) is an irregular heart rhythm characterised by rapid and chaotic electrical signals within the atria. The abnormal electrical activity and inefficient contractions of the atria in AF can cause blood to pool in the left atrium. This stagnant blood can promote the enlargement of the atrium over time.


Cardiomyopathy refers to a group of diseases that weaken the heart muscle. Two types of cardiomyopathies commonly associated with left atrial enlargement are:

  • Hypertrophic cardiomyopathy: This condition involves the thickening of the heart muscle, particularly in the left ventricle. The increased thickness of the ventricular wall can lead to elevated pressure within the left atrium, causing its enlargement.
  • Dilated cardiomyopathy: In this form of cardiomyopathy, the heart chambers become enlarged and weakened. As the heart's pumping ability is compromised, the left atrium may enlarge as it tries to compensate for the reduced cardiac output.

Congenital heart defects 

Some individuals are born with congenital heart defects that can contribute to left atrial enlargement. For example, atrial septal defects (ASDs) and ventricular septal defects (VSDs) are conditions where there are openings or holes in the walls separating the chambers of the heart. These defects can cause abnormal blood flow patterns and increased pressure in the left atrium, leading to its enlargement.

Other factors

Certain other factors and conditions can also play a role in left atrial enlargement, including:

  • Chronic lung diseases: Conditions such as chronic obstructive pulmonary disease (COPD) or pulmonary hypertension can elevate pressure within the pulmonary (lung) circulation, placing additional strain on the left atrium
  • Obesity: Excess body weight can contribute to the development of hypertension and act as a risk factor for cardiovascular diseases, increasing the likelihood of left atrial enlargement
  • Sleep apnoea: Sleep apnoea, characterised by recurrent pauses in breathing during sleep, has been associated with left atrial enlargement due to the repeated episodes of low oxygen levels and increased pressure on the heart
  • Medications: Certain medications, such as long-term use of corticosteroids, can have an impact on heart structure and contribute to left atrial enlargement

It's important to note that left atrial enlargement is often multifactorial, with several of these causes intertwining and influencing one another. Understanding the underlying cause of left atrial enlargement is crucial in guiding treatment strategies and addressing associated risk factors to prevent further enlargement and potential complications.1

Signs and symptoms of left atrial enlargement

Left atrial enlargement may not always present noticeable symptoms, especially in its early stages. However, when symptoms do occur, they can vary depending on the underlying cause, the extent of enlargement, and individual factors. Here are some common signs and symptoms associated with left atrial enlargement:

  • Shortness of breath (dyspnea)
  • Fatigue and weakness
  • Irregular heartbeats (arrhythmias)
  • Dizziness and fainting (syncope)
  • Chest pain or discomfort
  • Coughing or wheezing

It's important to note that these symptoms can also be associated with other cardiac or respiratory conditions. Therefore, a thorough evaluation by a healthcare professional is essential to determine the underlying cause of the symptoms and develop an appropriate treatment plan.

Management and treatment for left atrial enlargement

The management of left atrial enlargement aims to address the underlying cause, alleviate symptoms, prevent complications, and improve overall heart health. The specific treatment approach will depend on the individual's condition, the severity of left atrial enlargement, and any associated cardiovascular issues.


Depending on the underlying cause and associated conditions, healthcare professionals may prescribe medications to manage left atrial enlargement. These medications may include:

Lifestyle modifications 

Adopting a heart-healthy lifestyle can significantly contribute to the management of left atrial enlargement. Healthcare professionals may recommend the following lifestyle modifications:

Treatment of underlying conditions 

Addressing and managing underlying conditions that contribute to left atrial enlargement are important aspects of treatment. This may involve:

  • Managing high blood pressure: If hypertension is an underlying cause, aggressive blood pressure control through lifestyle modifications and medications can help prevent further enlargement
  • Treating heart valve diseases: Depending on the severity of the valve disease, surgical interventions, such as valve repair or replacement, may be necessary to alleviate pressure on the left atrium and restore proper valve function.
  • Managing atrial fibrillation: Controlling the heart rate and rhythm in individuals with atrial fibrillation through medications, cardioversion, or catheter ablation can help prevent complications and minimise left atrial enlargement

Regular monitoring and follow-up

Individuals with left atrial enlargement require regular monitoring to assess the effectiveness of treatment and detect any changes or complications. This may involve periodic echocardiograms, electrocardiograms (ECGs), or other imaging tests to evaluate the size and function of the left atrium and overall cardiac health. Healthcare professionals may also monitor blood pressure and heart rhythm and adjust medication dosages as needed.

In some cases, when left atrial enlargement is severe and associated with significant symptoms or complications, surgical interventions may be considered. These can include left atrial reduction, atrial fibrillation ablation procedures, or other cardiac surgeries, depending on the individual's specific condition.

It is crucial to work closely with healthcare professionals, including cardiologists or cardiac electrophysiologists, to develop an individualised treatment plan based on the underlying cause, overall health, and specific needs. Regular follow-up appointments and adherence to the prescribed treatment plan are essential for optimal management of left atrial enlargement and overall heart health.1


To diagnose left atrial enlargement, healthcare providers may employ various diagnostic tools and tests, including:

  • Physical examination: A thorough physical examination, including listening to the heart with a stethoscope, can provide initial clues to the presence of left atrial enlargement
  • Electrocardiogram (ECG): This non-invasive test records the heart's electrical activity and can help identify abnormal heart rhythms and patterns associated with left atrial enlargement
  • Echocardiography: This imaging test uses sound waves to create detailed images of the heart's structure and function, allowing for the measurement of the left atrium's size and detection of any abnormalities
  • Chest X-ray: X-ray images of the chest can reveal an enlarged left atrium or other potential causes of symptoms
  • Cardiac MRI or CT scan: These advanced imaging techniques provide detailed pictures of the heart, helping to assess the size and function of the left atrium and identify any underlying conditions

The specific diagnostic approach will depend on the individual's symptoms, medical history, and the healthcare provider's clinical judgment.1


Left atrial enlargement can lead to several potential complications, including:

  • Atrial fibrillation: The enlarged left atrium is more prone to develop atrial fibrillation, a condition characterised by irregular and rapid atrial contractions, increasing the risk of blood clots and stroke
  • Blood clots: The altered blood flow patterns and decreased effectiveness of atrial contractions in an enlarged left atrium can contribute to the formation of blood clots. These blood clots can then circulate throughout the body and create blockages in other areas.
  • Heart failure: If left untreated or poorly managed, left atrial enlargement can contribute to heart failure, a condition where the heart can't pump blood efficiently to meet the body's needs
  • Stroke: Blood clots originating from an enlarged left atrium can travel to the brain, causing a stroke. This can lead to significant neurological damage.
  • Pulmonary hypertension: In some cases, left atrial enlargement can result in increased pressure within the pulmonary circulation, leading to pulmonary hypertension and further complications

The timely identification and appropriate management of left atrial enlargement can help mitigate these potential complications.2


How can I prevent left atrial enlargement?

While not all causes of left atrial enlargement are preventable, lifestyle changes can help reduce the risk of disease progression.

How common is left atrial enlargement?

The prevalence of left atrial enlargement varies depending on the underlying causes and the population being studied. It is more commonly observed in individuals with conditions such as hypertension, mitral valve diseases, or atrial fibrillation. Timely diagnosis and appropriate management are crucial in preventing complications associated with left atrial enlargement.

Who is at risk of left atrial enlargement?

Certain factors increase the risk of developing left atrial enlargement, including:

  • High blood pressure
  • Heart valve diseases
  • Atrial fibrillation
  • Cardiomyopathy
  • Congenital heart defects

What can I expect if I have left atrial enlargement?

If you have left atrial enlargement, your healthcare provider will develop a treatment plan tailored to your specific needs. The management may involve medications, lifestyle modifications, or surgical interventions, depending on the underlying cause and associated symptoms. Regular follow-up appointments will be necessary to monitor your heart health and assess treatment effectiveness.2

When should I see a doctor?

If you experience symptoms such as shortness of breath, irregular heartbeats, chest discomfort, or unexplained fatigue, it is advisable to consult a healthcare professional. These symptoms can be associated with various cardiac conditions, including left atrial enlargement. Early diagnosis and intervention can help prevent complications and promote better outcomes.2


Left atrial enlargement, characterised by the enlargement of the left atrium, can result from various underlying conditions, including high blood pressure, heart valve diseases, atrial fibrillation, or congenital heart defects. While some cases may not exhibit noticeable symptoms, others may cause shortness of breath, fatigue, irregular heartbeats, or chest discomfort.

Proper diagnosis, treatment, and management are essential to prevent potential complications and promote heart health. By addressing the underlying cause, adopting a healthy lifestyle, and following the guidance of healthcare professionals, individuals with left atrial enlargement can effectively manage their condition and improve their overall well-being.


  1. Parajuli P, Ahmed AA. Left atrial enlargement. StatPearls Publishing; 2022.https://www.ncbi.nlm.nih.gov/books/NBK553096/ 
  2. Patel DA, Lavie CJ, Milani RV, Shah S, Gilliland Y. Clinical implications of left atrial enlargement: a review. Ochsner J [Internet]. 2009 Winter [cited 2023 Jul 18];9(4):191–6. Available from: https://www.ochsnerjournal.org/content/9/4/191?utm_source=TrendMD&utm_medium=cpc&utm_campaign=Ochsner_Journal_TrendMD_1
This content is purely informational and isn’t medical guidance. It shouldn’t replace professional medical counsel. Always consult your physician regarding treatment risks and benefits. See our editorial standards for more details.

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Rida Peerzada

Msc Global Healthcare Management, University College London

Rida is a Physical Therapist, with a background in marketing and business strategy honing these skills through her start-up ventures. Rida has 3 years of clinical and nearly 3 years of marketing and content creation experience.

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