Understanding Mitral Valve Regurgitation

What is Mitral Valve Regurgitation?

Mitral valve regurgitation, often called "mitral regurgitation" or "MR," is a heart condition where your mitral valve doesn't close properly. This allows blood to flow backward from your heart's left ventricle into the left atrium, rather than moving forward to supply your body with oxygen-rich blood. Think of it like a door that doesn't shut completely, allowing some of what should stay in one room to leak back into another.

This condition affects millions of people worldwide and can range from very mild, requiring only monitoring, to severe cases that need medical intervention. Understanding your condition is the first step toward managing it effectively.

Understanding Your Mitral Valve

Your heart has four chambers and four valves that work together to pump blood efficiently throughout your body. The mitral valve sits between your heart's left atrium (upper chamber) and left ventricle (lower chamber). It has two leaflets that open and close with each heartbeat, ensuring blood flows in only one direction.

The mitral valve is a complex structure made up of several parts: the leaflets themselves, supporting structures called chordae tendineae (which work like guy-wires on a tent), papillary muscles that anchor these supports, and the annulus (the ring around the valve opening). When any of these components don't work properly, mitral regurgitation can develop.

Types of Mitral Valve Regurgitation

Medical professionals classify mitral regurgitation into several categories to help determine the best treatment approach. The condition can be acute or chronic, and it can be primary or secondary.

Acute vs. Chronic Mitral Regurgitation

Acute mitral regurgitation develops suddenly and is considered a medical emergency. This might occur due to a heart attack that damages the heart muscle supporting the valve, infection, or trauma. When this happens, your heart hasn't had time to adapt, and you may experience severe symptoms quickly.

Chronic mitral regurgitation develops gradually over months or years. Your heart has time to compensate by growing larger and working harder, which means you might not notice symptoms for a long time. This is the more common form of the condition.

Primary vs. Secondary Mitral Regurgitation

Primary mitral regurgitation means the problem lies directly with the mitral valve itself. The valve leaflets, supporting structures, or surrounding tissue are damaged or abnormal. This is like having a broken door that won't close properly because the door itself is warped or damaged.

Secondary mitral regurgitation occurs when the mitral valve is structurally normal, but doesn't work properly because of problems with the heart muscle. This might happen when the left ventricle becomes enlarged or weakened, pulling the valve leaflets apart so they can't close completely. It's like having a perfectly good door that won't close because the door frame has shifted.

What Causes Mitral Valve Regurgitation?

The causes of mitral regurgitation depend on whether you have the primary or secondary type.

Primary Mitral Regurgitation Causes

The most common cause of primary mitral regurgitation in developed countries is mitral valve prolapse, a condition where the valve leaflets bulge backward into the left atrium. This can occur due to myxomatous degeneration, where the valve tissue becomes thickened and redundant, or fibroelastic deficiency, where weakened connective tissue leads to ruptured supporting structures.

Other causes of primary mitral regurgitation include rheumatic heart disease (more common in developing countries), infective endocarditis (infection of the heart valve), connective tissue disorders, congenital heart defects, and rarely, radiation therapy to the chest.

Secondary Mitral Regurgitation Causes

Secondary mitral regurgitation typically results from heart muscle problems that affect the valve's ability to close properly. Coronary artery disease and heart attacks can damage the heart muscle, while cardiomyopathy (disease of the heart muscle) can cause the left ventricle to enlarge and change shape.

Atrial fibrillation and other conditions that cause the left atrium to enlarge can also lead to secondary mitral regurgitation by stretching the valve opening beyond what the leaflets can cover.

Recognizing the Symptoms

Many people with mild mitral regurgitation have no symptoms at all. When symptoms do develop, they often appear gradually and may include shortness of breath, especially during physical activity or when lying flat. You might notice fatigue or feeling unusually tired during normal daily activities.

Some people experience heart palpitations, feeling like their heart is racing, pounding, or skipping beats. In more severe cases, you might develop swelling in your legs, ankles, or feet, or have difficulty breathing at night.

It's important to understand that symptoms can develop very slowly over years, making them easy to dismiss as normal signs of aging or being out of shape. However, any new or worsening symptoms should be discussed with your healthcare provider.

How is Mitral Regurgitation Diagnosed?

The diagnostic process usually begins with your doctor listening to your heart with a stethoscope. Mitral regurgitation often creates a distinctive heart murmur that trained healthcare providers can detect.

The primary test used to diagnose and assess mitral regurgitation is echocardiography, commonly called an "echo." This ultrasound test creates pictures of your heart and allows doctors to see how well your valves are working, measure the amount of regurgitation, and assess how your heart is responding to the condition.

Your doctor will likely stage your condition from A through D. Stage A means you're at risk but don't yet have regurgitation. Stage B indicates mild to moderate regurgitation. Stage C represents severe regurgitation without symptoms, while Stage D means you have severe regurgitation with symptoms.

Additional tests might include electrocardiograms to check your heart's electrical activity, chest X-rays to see your heart size and check for fluid in your lungs, or cardiac catheterization in some cases to get more detailed information about your heart function and coronary arteries.

Treatment Options

Treatment for mitral regurgitation depends on several factors: the severity of your condition, whether you have symptoms, how well your heart is functioning, and what caused the regurgitation in the first place.

Watchful Waiting and Monitoring

If you have mild to moderate mitral regurgitation without symptoms, your doctor may recommend regular monitoring with periodic echocardiograms. This approach allows your medical team to track any changes in your condition and intervene if needed before permanent heart damage occurs.

Medical Treatment

For secondary mitral regurgitation, medical treatment focuses on addressing the underlying heart condition. This might include medications to strengthen heart function, control blood pressure, or manage heart rhythm abnormalities. Heart failure medications such as ACE inhibitors, beta-blockers, or newer medications like sacubitril/valsartan may be prescribed.

In some cases, cardiac resynchronization therapy (a special type of pacemaker) or coronary revascularization procedures might help improve heart function and reduce regurgitation.

Surgical Options

Mitral valve repair is generally preferred over replacement when possible, especially for primary mitral regurgitation. Repair techniques can fix problems with the valve leaflets, tighten the valve ring, or replace damaged supporting structures. When performed by experienced surgeons, mitral valve repair has excellent long-term results with very low operative risk.

Mitral valve replacement might be necessary when the valve is too damaged to repair effectively. Modern artificial valves, whether mechanical or biological, provide good long-term function, though each type has specific considerations regarding blood-thinning medication requirements.

Transcatheter Procedures

For patients who are at high risk for traditional open-heart surgery, newer minimally invasive procedures may be options. The MitraClip procedure uses a small device delivered through a blood vessel to clip the valve leaflets together, reducing regurgitation. This procedure has shown good results in carefully selected patients with both primary and secondary mitral regurgitation.

Living with Mitral Valve Regurgitation

Many people with mitral regurgitation live normal, active lives. Regular follow-up with your cardiologist is essential to monitor your condition and adjust treatment as needed. The frequency of these visits will depend on the severity of your regurgitation and how quickly it might be progressing.

Staying physically active within the limits recommended by your doctor can help maintain cardiovascular fitness and overall health. Most people with mild to moderate mitral regurgitation can participate in regular exercise, though those with severe regurgitation may need to avoid very strenuous activities.

Maintaining good dental hygiene and informing your dentist about your valve condition is important, as dental procedures can sometimes introduce bacteria into the bloodstream. Your doctor will advise whether you need antibiotics before certain dental procedures.

If you have atrial fibrillation along with mitral regurgitation, taking prescribed blood-thinning medications exactly as directed is crucial to prevent stroke.

When to Contact Your Doctor

Seek immediate medical attention if you develop sudden, severe shortness of breath, chest pain, or feel like you're going to faint. These could be signs of acute, severe mitral regurgitation or other serious heart problems.

Schedule an appointment with your healthcare provider if you notice new or worsening symptoms such as increased shortness of breath, unusual fatigue, swelling in your legs or feet, or heart palpitations. Even if your symptoms seem mild, changes in how you feel can provide important information about your condition.

Don't skip your scheduled follow-up appointments, even if you feel well. Regular monitoring allows your medical team to detect changes before they become problematic and ensures you receive the most appropriate care for your individual situation.

Looking Forward

Research continues to advance our understanding and treatment of mitral regurgitation. New surgical techniques, improved transcatheter devices, and better medical therapies are constantly being developed and refined. This means that treatment options continue to improve, offering hope for better outcomes and quality of life for people with this condition.

The key to successful management is working closely with your healthcare team, staying informed about your condition, and following your treatment plan. With proper care and monitoring, most people with mitral regurgitation can maintain good health and an active lifestyle.

Remember that having mitral regurgitation doesn't define you or limit your potential for a fulfilling life. By understanding your condition and taking an active role in your care, you're taking important steps toward maintaining your heart health and overall well-being.

August 2025

Prepared by Professor Eric Lim for PEACHealth with background research and drafting assistance by LLM.