Introduction 

Do you know that your lifestyle can physically affect your heart and the effect can be either good or bad? According to a study, lifestyle changes affect what you eat, how much you participate in activities and how well you sleep plays a great role in the development, progression and management of heart conditions. One of the important changes in your heart health is left atrial remodelling. It refers to changes in structure and function in the left upper chamber of your heart, the atrium. These changes often occur as a result of chronic stress placed on your heart by conditions such as high blood pressure, heart failure, diabetes and obesity.

Lifestyle modifications can reduce these stressors and in many cases, help prevent or even reverse the remodelling process in your heart. In this article, we‘ll explore left atrial remodelling, causes and lifestyle modifications and their effects on this condition.

The atrium 

The atrium is one of the upper chambers of your heart. Your left atrium specifically receives blood that contains oxygen from your lungs. It then sends this blood to your left ventricle, from where it is then pumped round your body.

If there is a remodelling in your left atrium, it means its structure and shape will not be able to support this function. This has effects on your body.

What is left atrial remodelling?

Left atrial (LA) remodelling refers to disease-related changes in the mechanical, electric, ionic and molecular makeup of your heart.¹ These components are involved because they work together for your left atrium to perform its function. You have these changes mostly because of stress from health conditions like high blood pressure, heart failure, excessive blood sugar and obesity. The changes may also be caused by the inability of your left ventricle to contract and relax properly. Activation of certain hormones and inflammation in your body can also cause them.² If you have left atrial remodelling, you can develop problems like atrial fibrillation (an irregular heartbeat) and have difficulty in filling your left ventricle with blood. You may also have blood clots that may cause strokes or other blockages and there can be heart failure or even death.²

The damage to the structure and function of your left atrium usually depends on the type, how severe and the amount of time you are exposed to the stressors.¹ The changes can be reversible, while some are not.¹ If the change occurs suddenly, it can be reversed, but if over a prolonged time, it may be irreversible.³

Outcome of left atrial remodelling 

The prognosis of left atrial remodelling is not always good. However, if you receive early intervention, the condition might stop and your atrium will begin to return back to its original structure and function.¹ This is known as left atrial reverse remodelling.

Different manifestations of left atrial remodelling 

Left atrial (LA) remodelling varies based on the specific cause. Different manifestations include:

Structural remodelling 

This is when your left atrium physically changes over time, either adapting to stress or becoming damaged.⁴ These changes can be macroscopic, like in atrial dilatation- your atrial muscle gets enlarged due to pressure or (microscopic, in your atrium cells)

• Grow larger (hypertrophy)
• Break down (myolysis)
• Lose their usual structure (dedifferentiation)
• Become scarred (fibrosis)
• Die (apoptosis) 

Functional remodelling 

Here, your left atrium isn’t working as well as it should (reduced performance). This can happen with or without the atrium becoming enlarged. It is often caused by atrial tachyarrhythmias or changes in left atrial pressure.⁴

Electrical remodelling 

This involves changes in the electrophysiological properties of your atrial cells. This affects how electrical signals move through your heart. It can manifest as shortened action potential duration, reduced atrial refractory period and slower conduction velocity. It can also involve changes in ion channel activities and cell-to-cell electrical communication.⁴

Major causes of left atrial remodelling 

Hypertension

When your blood pressure is high for a long time, it causes the muscles of your atrium to increase so as to accommodate the resultant pressure. The enlargement can be above normal leading to structural remodelling.⁵

Obesity

It contributes to atrial remodelling in many ways. Your left atrial muscles enlarge because of increased pressure during filling. Also, adipose tissue in obesity produces substances that can cause inflammation. This can cause injury to your atrial muscles.⁵

Chronic inflammation

Inflammation contributes to electrical and structural remodelling of your atria.

Several substances linked to inflammation, such as C-reactive protein, certain immune system proteins (like IL-6, IL-8, and TNF), and other molecules like myeloperoxidase and galectin-3, play a role.⁵

Ageing

Ageing generally causes body changes. Your left atrium can increase in size and volume or become stiffer. You also have reduced electrical activities in your heart.⁶

Diabetes

If you don't control your blood sugar levels, it can lead to structural remodelling. This means that the shape of your atrium changes, especially enlargement. The cells can also die.⁸

Race

Although it is underreported, research says electrical remodelling occurs earlier in Black hypertensive patients.⁶

Sleep apnoea

It shortens the time your atrium resets between beats. It can also put extra pressure on your heart and may lead to thickening and scarring of your heart muscle.⁶

Aortic stenosis

If your left ventricle does not fill properly with blood, the blood gushes back or remains in the left atrium (afterload). This can cause problems in the shape and function.⁴

Mitral valve disease

When your mitral valve becomes tiny, it delays blood flow into your left ventricle, the blood flows back to your left atrium. This can make it to enlarge.¹

Lifestyle modifications that can help against left atrial remodelling 

Weight management

 A study shows that when you lose weight, your atrial size reduces too. Also, when you lose weight, the strain on your atrium reduces. This can prevent changes in the structure and function of your atrium.

Exercise 

Exercise generally is good for your heart. It helps blood to flow properly. WHO recommends at least 150 minutes of moderate exercise per week.

Blood pressure control

Keeping your blood pressure in control will keep you away from many heart conditions.

You can control your blood pressure through 

Diet

The DASH diet is the recommended diet for controlling high blood pressure. It is made up of foods low in sodium and those that contain nutrients that help lower blood pressure. They include fruits, vegetables, whole grains, lean protein and low-fat dairy.

Medications 

Antihypertensive drugs have been shown to prevent left atrial dilatation 

and favour reverse remodelling.⁵ 

Getting enough sleep 

According to the CDC, lack of sleep leads to conditions like high blood pressure, obesity and type 2 diabetes. These are risk factors for heart conditions. Getting at least 7–9 hours of sleep per night saves you from these conditions that cause left atrial remodelling.

Eating a heart-healthy diet 

Heart-healthy and anti-inflammatory diets like leafy green vegetables, such as spinach and broccoli; dark yellow vegetables, which include carrots, peppers, pumpkin, and beans; fruits, like berries; and whole grains, such as brown rice, reduces the risk of heart related conditions.⁹ Also limiting processed foods will keep your heart healthier. Studies show that you are at a greater risk of heart-related conditions any time you consume processed food.⁹ This is mostly because of additives used in processing them and germs produced during processing.

Avoidance of alcohol and smoking 

If you consume alcohol for a long time, it causes atrial remodelling.¹⁰ Alcohol reduction or even avoidance is linked to overall good health. Your atrial layers change any time you smoke. And this change is negative. Avoidance will keep your heart healthy.

Stress reduction

Stress affects all areas of your body, including your heart. Reducing stress and getting enough rest helps your body function well, including your heart.

Summary 

Left atrial remodelling refers to structural and functional changes in the left atrium, often resulting from prolonged stress on the heart due to conditions like high blood pressure, obesity, diabetes, and sleep apnea. These changes may affect the atrium’s ability to pump blood effectively, leading to complications such as atrial fibrillation, blood clots, and heart failure. Key causes include hypertension, obesity, chronic inflammation, aging, diabetes, race-specific risks, and sleep disorders. Lifestyle modifications such as weight loss, regular exercise, blood pressure management, adequate sleep, healthy eating, alcohol and tobacco avoidance, and stress reduction can help prevent, reduce, or even reverse remodelling.