Mitral Valve Regurgitation

Overview

Mitral valve regurgitation is a condition in which the mitral valve which sits between the heart's left upper and left lower chambers does not close completely after each heartbeat. When the left lower chamber contracts, a properly functioning mitral valve seals shut and keeps blood moving forward. In mitral regurgitation, the valve fails to close fully and some of the blood that has been pumped flows backward into the left upper chamber.

Because the heart must pump both the forward volume and the leaked volume with every beat, the left lower chamber gradually becomes overloaded. The heart can compensate for this extra demand in the early stages and a person may have no symptoms for years. Over time, however, the sustained overload causes the chamber to enlarge, and its walls initially thickened as a compensatory response may eventually thin and weaken. This progression can lead to heart failure and lasting damage to the heart muscle.

Mitral regurgitation can develop gradually as a chronic condition, or it can arise suddenly in the setting of a heart attack or infective endocarditis. Acute mitral regurgitation is a medical emergency that requires immediate intervention.

Symptoms

Chronic mitral regurgitation may produce no symptoms for a prolonged period. Symptoms typically emerge when the heart's ability to compensate begins to be exceeded. Their nature and severity depend on the degree of regurgitation and how quickly it has progressed.

• Shortness of breath. This is one of the most common symptoms. It may initially occur only during exertion such as climbing stairs or walking briskly. Over time, breathlessness can also develop at rest or when lying flat. Waking from sleep unable to breathe comfortably is an important warning sign.
• Fatigue and weakness. As the heart's pumping efficiency declines, less blood reaches the body and a persistent sense of exhaustion may develop. Everyday activities can feel increasingly tiring.
• Palpitations or irregular heartbeat. As the left upper chamber enlarges, an irregular heart rhythm called atrial fibrillation can develop. The heart may feel as though it is racing, fluttering, or beating out of rhythm. Atrial fibrillation both worsens symptoms and raises the risk of stroke.
• Swelling in the legs and ankles. As heart failure advances, fluid can accumulate in the body.
• Reduced exercise capacity. Physical activities that were previously manageable may progressively produce fatigue or breathlessness more quickly.
• Cough. A persistent cough that worsens when lying flat can be related to increased pressure in the lungs.

In acute mitral regurgitation, symptoms develop very rapidly. Because the heart has not had time to adapt to the sudden volume overload, acute heart failure can develop within hours. This is a medical emergency.

When to Seek Medical Care

See a doctor if you notice any of the following.

• Shortness of breath during activity or at rest
• Breathlessness when lying flat that wakes you from sleep
• Palpitations or a sensation of irregular heartbeat
• Unexplained fatigue and a decline in exercise capacity
• Swelling in the legs or ankles

Call emergency services immediately if you experience any of the following.

• Sudden, severe shortness of breath
• Sudden, severe chest pain
• Fainting or nearly fainting
• A very rapid or markedly irregular heartbeat

Causes

Mitral regurgitation has several possible underlying causes. Identifying the specific cause influences both the treatment approach and surgical planning.

• Mitral valve prolapse. The most common cause in developed countries. The abnormal backward bulging of the leaflets can gradually lead to increasingly significant leaking over time.
• Rheumatic heart disease. Untreated streptococcal throat infections can cause rheumatic fever, which leaves permanent scarring on the mitral valve leaflets. Rheumatic disease can produce both stenosis and regurgitation.
• Heart enlargement and heart failure. When the heart enlarges for any reason, the ring supporting the mitral valve stretches and the leaflets can no longer close fully. This is called functional mitral regurgitation because it arises from changes in the heart's geometry rather than from disease of the valve leaflets themselves.
• Heart attack. A heart attack can damage the papillary muscles — structures attached to the left ventricle wall that hold the mitral valve closed during contraction. Injury or rupture of these muscles can cause sudden and severe mitral regurgitation, which is a surgical emergency.
• Infective endocarditis. Bacterial infection of the mitral valve leaflets can destroy their tissue and cause rapidly progressive regurgitation.
• Age-related degeneration. Progressive wear of the valve leaflets over time can contribute to regurgitation, particularly in older adults.
• Radiation damage. Radiotherapy delivered to the chest can affect the mitral valve over time.
• Congenital valve abnormalities. Some people are born with structural differences in the mitral valve.

Risk Factors

• A history of mitral valve prolapse. People with prolapse carry a risk of progressive regurgitation over time and require regular monitoring.
• A history of rheumatic fever. Particularly untreated or recurrent rheumatic fever predisposes to valve damage.
• Known heart failure or dilated cardiomyopathy. The risk of functional mitral regurgitation increases as the heart enlarges.
• A prior heart attack. Particularly heart attacks affecting the inferior and posterior wall of the left ventricle can damage the papillary muscles and cause regurgitation.
• Older age. Degenerative changes in the valve tissue increase with age.

Diagnosis

The diagnosis of mitral regurgitation is established through clinical assessment and imaging. Accurately measuring the severity and the state of the left lower chamber is essential for determining the monitoring plan and the timing of any intervention.

• Medical history and physical examination. The onset and progression of symptoms are discussed. A history of mitral valve prolapse, rheumatic fever, prior heart attack, or infective endocarditis is specifically relevant. When the doctor listens to the heart, a murmur heard during systole (the phase when the heart contracts) is the hallmark of mitral regurgitation. The character and intensity of the murmur provide an initial indication of severity.
• Echocardiogram (heart ultrasound). The cornerstone of diagnosis and monitoring. It quantifies the degree of blood leaking backward, identifies which leaflet is affected and what the underlying cause is, and measures the size of the left lower chamber, wall thickness, and ejection fraction. It also assesses left upper chamber enlargement. Serial measurements of left ventricular dimensions and ejection fraction directly determine the timing of surgery. Three-dimensional echocardiography provides highly detailed anatomical images of the valve and is valuable for assessing whether it is suitable for repair.
• Transesophageal echocardiography. In this technique, an ultrasound probe is passed into the esophagus to obtain much more detailed images of the mitral valve than are possible from outside the chest. It is critically important for surgical planning identifying precisely which part of which leaflet is affected and confirming that the valve can be repaired. It is also the preferred test when infective endocarditis is suspected.
• Cardiac MRI. Provides precise measurements of left ventricular volumes and dimensions, and can quantify the volume of regurgitation accurately. It is particularly useful when echocardiographic image quality is suboptimal and is increasingly used to support decision-making around surgical timing.
• Electrocardiogram (ECG). Used to identify electrical changes related to left upper chamber enlargement and to detect atrial fibrillation.
• Holter monitor. Worn for 24 hours or longer to detect intermittent atrial fibrillation or other rhythm disturbances that may not be captured on a standard ECG.
• Exercise stress test. May be used in apparently asymptomatic patients to objectively measure exercise capacity and reveal symptoms that are not apparent at rest. The blood pressure and exercise tolerance response can inform surgical timing decisions.
• Coronary angiography or coronary CT angiography. Before valve surgery or intervention, the coronary arteries are assessed. If significant coronary artery disease is found, bypass surgery can be performed at the same time as the valve procedure.

Treatment

Treatment of mitral regurgitation depends on its severity, the state of the left lower chamber, the presence of symptoms, and the underlying cause. The primary goals are to relieve symptoms, intervene before permanent left ventricular damage develops, and prevent complications. Timing is critical.

Monitoring

In mild to moderate regurgitation, the left ventricle is monitored at regular intervals with echocardiography. Enlargement of the left ventricle or a fall in ejection fraction are the most important indicators that the time for surgery is approaching. Any new symptoms that develop during this monitoring period should prompt immediate medical attention.

Medications

Medications cannot correct the valve problem itself but relieve symptoms and help prevent complications.

• Heart failure medications. When left ventricular function begins to decline, ACE inhibitors or ARBs, beta-blockers, and SGLT2 inhibitors are added to the treatment plan. These medications protect the heart and slow adverse remodeling.
• Diuretics. Remove excess fluid from the body and relieve breathlessness and swelling.
• Atrial fibrillation management. When atrial fibrillation develops, rate-controlling medications and blood-thinning therapy to reduce the risk of stroke are typically required.
• Blood pressure medications. Particularly in functional mitral regurgitation, vasodilating drugs reduce the workload on the left ventricle and can modestly decrease the volume of the backward leak.

Valve Repair

Repairing the existing valve is strongly preferred over replacing it whenever feasible. Mitral valve repair is the gold standard treatment for prolapse-related mitral regurgitation and produces excellent long-term outcomes.

• Repair techniques. The surgeon corrects the abnormal portion of the leaflet, repairs or replaces ruptured or elongated chords that hold the leaflets in position, and reinforces the valve ring with an annuloplasty ring. At experienced centers these techniques are applied with very high success rates.
• Advantages of repair. Because the patient's own valve is preserved, lifelong anticoagulation is not required. Left ventricular function is better preserved over the long term. The durability of repair at experienced centers is excellent.
• Minimally invasive approaches. At experienced centers, mitral valve repair can be performed through small incisions or using robotic surgical techniques, which can shorten recovery time.

Valve Replacement

When repair is not feasible for example, when the valve leaflets are extensively damaged from rheumatic disease or infective endocarditis replacement is performed.

• Biological valve. Derived from animal or human donor tissue. Does not require long-term anticoagulation, but gradually deteriorates over ten to twenty years and may eventually need replacement. Generally preferred in older patients or those who cannot safely take long-term anticoagulation.
• Mechanical valve. Very durable and rarely requires re-replacement. Lifelong warfarin anticoagulation is mandatory because of the clotting risk. Generally preferred in younger patients who can reliably manage long-term anticoagulation.

Catheter-Based Interventions

• MitraClip. In suitable patients who carry a high surgical risk, a clip delivered through a catheter passed through a blood vessel in the groin can be used to draw the mitral valve leaflets together, reducing the backward leak. It does not require open heart surgery. The procedure is not suitable for all patients and depends on the specific anatomy of the valve.
• Transcatheter mitral valve replacement. Still in development, this approach may become available for a wider group of patients in the coming years. Discuss with your cardiologist whether this might be relevant to your situation.

Functional Mitral Regurgitation: A Special Consideration

When mitral regurgitation results from heart enlargement rather than from disease of the valve itself, the primary goal is to treat the underlying heart failure and its cause. Heart failure medications and cardiac resynchronization therapy (a device that coordinates the contraction of both lower chambers) can meaningfully reduce functional mitral regurgitation. Valve intervention in this group is reserved for carefully selected patients.

Complications

Without adequate treatment and monitoring, mitral regurgitation can lead to serious complications over time.

• Permanent left ventricular damage. Prolonged overloading of the left ventricle causes progressive enlargement and eventual weakening. Beyond a certain threshold, this damage may not fully reverse even after successful valve repair or replacement. This is why the timing of intervention is so important.
• Heart failure. Sustained left ventricular damage can evolve into chronic heart failure that persists after valve treatment.
• Atrial fibrillation. Enlargement of the left upper chamber predisposes to atrial fibrillation, which both worsens symptoms and increases stroke risk.
• Stroke. Clot formation associated with atrial fibrillation can cause a stroke. Anticoagulation therapy reduces this risk.
• Pulmonary hypertension. Elevated pressure in the left upper chamber can be transmitted back to the pulmonary arteries (the vessels supplying the lungs) causing pulmonary hypertension over time. This worsens symptoms and increases surgical risk.

Lifestyle

Living with mitral regurgitation requires long-term attention and monitoring. The right measures can slow disease progression and preserve quality of life.

Physical Activity

Many people with mild to moderate regurgitation and no significant symptoms can maintain a near-normal level of physical activity. In severe regurgitation, vigorous exercise and competitive sport increase the load on the left ventricle and may not be appropriate. The specific type and intensity of activity that is safe for you should be determined by your cardiologist.

Blood Pressure Control

Elevated blood pressure increases the workload on the left ventricle and worsens regurgitation. Keeping blood pressure consistently within target values is one of the most effective protective steps. Regular home blood pressure monitoring is recommended.

Salt and Fluid Intake

In patients with heart failure symptoms, reducing daily salt intake helps prevent fluid accumulation and relieves breathlessness and swelling. Ask your doctor for a specific daily salt target appropriate to your situation.

Daily Weight Monitoring

Weighing yourself at the same time each morning and recording the result is a practical way to detect fluid buildup early. A notable weight gain over a short period should prompt you to contact your doctor.

Medications

Taking prescribed medications consistently is essential. After valve replacement, the medication regimen changes depending on the type of valve used. Patients with a mechanical valve must manage warfarin therapy carefully, with regular INR monitoring. Do not stop any medication without medical guidance. Always inform any other treating doctor about your valve condition and medications before a new drug is started.

Protecting Against Infective Endocarditis

Some patients with mitral regurgitation are advised to take antibiotics before dental procedures and certain surgeries. Inform your dentist and every treating healthcare professional about your valve condition. Good oral hygiene is also an important protective measure.

Regular Follow-up

Mitral regurgitation requires regular echocardiography and cardiology review. Left ventricular size and ejection fraction are assessed at defined intervals. The frequency of follow-up depends on the severity of the condition. Do not wait for a scheduled appointment if new symptoms develop. Contact your doctor or seek emergency care if any of the following occur.

• Shortness of breath that returns or worsens
• Difficulty breathing when lying flat
• Swelling in the legs or ankles that is new or increasing
• Palpitations or a sensation of irregular heartbeat
• A noticeable decline in exercise capacity
• Fever with sweating and fatigue, which may suggest a valve infection

Preparing for Your Appointment

Coming prepared to an appointment for mitral valve regurgitation helps your doctor make a more accurate assessment and choose the most appropriate treatment for you.

What You Can Do

• Write down when symptoms began and how they have progressed.
• Bring any previous echocardiography reports. Left ventricular dimensions and ejection fraction values are particularly important.
• Share any history of mitral valve prolapse, rheumatic fever, or prior heart attack.
• List all medications and supplements you are currently taking.
• Mention any upcoming dental procedures or surgical plans.
• Write your questions down before the appointment.

Questions You May Wish to Ask Your Doctor

• How severe is my regurgitation?
• What is the current state of my left ventricle and has it enlarged?
• Do I need surgery or another intervention now or in the near future?
• Would valve repair or replacement be more appropriate?
• Could MitraClip be an option for me?
• What type and intensity of exercise is safe for me?
• Do I need to take antibiotics before dental treatment?
• How often do I need follow-up appointments?

Questions Your Doctor May Ask You

• When did symptoms begin and how have they progressed?
• Does breathlessness worsen when lying flat?
• Is there a history of mitral valve prolapse, rheumatic fever, or a prior heart attack?
• Do you have known heart failure or an enlarged heart?
• What medications are you currently taking?
• Do symptoms worsen during exercise?
• Have you had a valve infection in the past?