Mitral Valve Regurgitation: The Leaking Valve and How It Is Treated
Key takeaways
- Mitral valve regurgitation is a leaking mitral valve: the valve between the two left chambers of the heart fails to close fully, so blood washes backwards with each beat.
- It has two broad causes: primary (a fault in the valve leaflets themselves) and secondary (a stretched or weakened heart pulling the valve open); the treatment differs between them.
- Symptoms of a significant leak include breathlessness, tiredness, palpitations, and swelling, though a mild leak often causes nothing at all and is found on a routine scan.
- Severity is graded on an echocardiogram, and treatment ranges from watchful monitoring, through surgical repair or replacement, to a keyhole MitraClip for those at high surgical risk.
- Whether and when to intervene is a decision for a heart team, based on the severity of the leak, your symptoms, and the strength of your heart muscle.
Published
Mitral valve regurgitation is a leaking mitral valve: the valve between the two chambers on the left side of the heart fails to close fully, so with each beat some blood washes backwards instead of being pumped cleanly forwards 1. My own trouble was a different valve, the aortic, but the mitral leak is the condition I was asked about most once people knew I wrote about hearts, usually in the same worried tone I once used: my doctor heard a murmur, what does it mean? Here is the plain answer.
What mitral regurgitation is
The mitral valve has two leaflets that should meet like a pair of doors, sealing tightly so blood flows one way only, from the upper left chamber into the lower one and out to the body. In regurgitation the doors do not close properly, and a portion of blood leaks back the wrong way 1. A small leak is common and often causes no trouble at all. A large one means the heart has to pump the same blood twice, and over time that extra work can stretch and tire the muscle. Mitral regurgitation is in fact one of the most common valve conditions seen in cardiology 2.
Primary and secondary: two different problems
The single most useful thing to understand is that there are two kinds of leak, and they are not really the same disease. Primary (degenerative) regurgitation is a fault in the valve itself: leaflets that have grown floppy, or a fine supporting cord that has stretched or snapped. Secondary (functional) regurgitation is a fault in the heart around the valve: a chamber that has enlarged or a muscle weakened, often after a heart attack, which pulls the leaflets apart so they can no longer meet 3. The distinction runs through everything that follows, because fixing a faulty valve and treating a failing heart muscle are different tasks.
The symptoms, and how they creep up
A mild leak usually causes nothing you would notice, and is often found only because a doctor hears a murmur or orders a scan for another reason. As the leak grows, the common symptoms are breathlessness, especially on exertion or when lying flat, tiredness, palpitations from an irregular heart rhythm, and swelling in the ankles 1. What struck me, hearing others describe it, was how familiar it sounded: like my own aortic story, these symptoms arrive so gradually that most people file them under getting older and carry on far too long before mentioning them.
How it is diagnosed and graded
Diagnosis usually begins with a heart murmur heard through a stethoscope, then is confirmed with an echocardiogram, an ultrasound of the heart that both shows the leaking jet and measures how severe it is 2. Sometimes a closer view is needed from a transoesophageal echo, where a small probe is passed down the gullet to sit just behind the heart. The severity grading matters enormously, because a mild leak and a severe leak lead to completely different plans, and because in secondary regurgitation the strength of the heart muscle is assessed at the same time.
The treatment options
Treatment depends on how severe the leak is and what is causing it. A mild leak may need nothing more than periodic monitoring with scans to watch for change. A severe, symptomatic leak is treated by correcting the valve, and here there are three broad routes: surgical repair, which is preferred whenever the valve can be mended rather than swapped; surgical replacement when repair is not possible, which I cover in heart valve replacement surgery; and a keyhole MitraClip for patients at high surgical risk, explained in MitraClip explained. Medicines play a supporting role, easing symptoms and, in secondary regurgitation, treating the underlying heart failure.
The evidence for the keyhole option is worth a specific mention. In heart-failure patients with secondary regurgitation, the COAPT trial found that transcatheter repair reduced hospitalisations for heart failure over two years to 35.8% of patients, against 67.9% with medication alone 4. That does not make it right for everyone; the choice between watching, operating, and clipping is a genuine judgement made by a heart team, weighing the severity of your leak, your symptoms, and the strength of your heart against the risks of each path.
General information, not medical advice. Mitral regurgitation ranges from harmless to serious, and the right treatment depends on its cause, its severity, and your own heart; please see a cardiologist for assessment of your particular valve.
References
- Mitral valve regurgitation, Mayo Clinic. ↩
- Heart valve disease, British Heart Foundation. ↩
- 2020 ACC/AHA Guideline for the Management of Patients With Valvular Heart Disease, American College of Cardiology / American Heart Association. ↩
- Transcatheter Mitral-Valve Repair in Patients with Heart Failure (COAPT), New England Journal of Medicine. ↩
Common questions
What is mitral valve regurgitation?
It is a leaking mitral valve. The mitral valve sits between the two chambers on the left side of the heart and should close fully with each beat so blood is pumped forwards only. In mitral regurgitation the leaflets do not seal, so some blood leaks backwards into the upper chamber. A mild leak is common and often harmless; a severe leak makes the heart work harder and can, over time, weaken it.
What are the symptoms of a leaking mitral valve?
A mild leak often causes no symptoms and is picked up when a doctor hears a murmur or orders a scan for another reason. As the leak grows, the common symptoms are breathlessness, especially on exertion or lying flat, tiredness, palpitations from an irregular heartbeat, and swelling in the ankles. These build gradually, so people often put them down to age, as I did with my own valve problem.
What is the difference between primary and secondary mitral regurgitation?
Primary regurgitation is a problem with the valve itself, such as leaflets that have become floppy or a supporting cord that has snapped. Secondary regurgitation is a problem with the heart around the valve: a chamber that has enlarged or a muscle that has weakened, pulling the leaflets apart so they no longer meet. The distinction matters because it changes the treatment, particularly the balance between fixing the valve and treating the heart muscle.
How is mitral regurgitation diagnosed?
It usually starts with a heart murmur heard through a stethoscope, then is confirmed and graded with an echocardiogram, an ultrasound of the heart that shows the leak and measures its severity. Sometimes a transoesophageal echo, with the probe passed down the gullet, gives a closer look at the valve, and other tests assess the heart muscle and rhythm before any decision about treatment.
How is a leaking mitral valve treated?
It depends on severity and cause. A mild leak may need only periodic monitoring with scans. A severe, symptomatic leak is treated by fixing the valve, either by surgical repair, which is preferred when possible, by surgical replacement, or by a keyhole MitraClip for patients at high surgical risk. Medicines are used to manage symptoms and, in secondary regurgitation, to treat the underlying heart failure.
Is mitral valve regurgitation dangerous?
A mild leak is usually not, and many people live with one for years under simple monitoring. A severe leak is more serious: left untreated in a symptomatic patient it strains the heart, can lead to heart failure and atrial fibrillation, and shortens life. That is why severe regurgitation is followed closely and treated once it causes symptoms or begins to affect the heart's function.
Written by Diane Farrow. Medically reviewed by Dr. Helena Voss, MD, FESC.
Our guides are written from personal experience and reviewed by a qualified clinician for accuracy. Read our editorial policy.
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