Mitral Regurgitation

Mitral regurgitation (MR) is a condition in which the heart's mitral valve (dual-flap valve between the left atrium and the left ventricle) doesn't close tightly, allowing blood to flow backward, or regurgitate, into the atrium, each time the left ventricle contracts. This reduces the amount of blood that flows to the rest of the body. As a result, the heart may try to pump harder, which may lead to congestive heart failure.

Some individuals with MR may not experience any symptoms, while others may experience one or more of the following symptoms:

• Heart palpitation: feeling that your heart is skipping a beat, fluttering or beating too hard or too fast
• Weakness and fatigue
• Shortness of breath: with exertion and/or at rest
• Lightheadedness
• Edema: swelling, of the feet or ankles

• Mitral valve prolapse (MVP): a condition in which the mitral valve leaflets (flaps) bulge, or prolapse, into the left atrium, potentially preventing the valve from closing tightly, leading to regurgitation
• Rheumatic fever: a complication of untreated strep throat, now rare in the U.S.
• Tissue cord damage: stretching or tearing of tissue cords that anchor the flaps of the mitral valve to the heart, which can cause sudden and substantial leakage of blood through the mitral valve
• Endocarditis: infection of the lining of the heart
• Heart attack
• Cardiomyopathy: abnormality of the heart muscle, caused by certain conditions, such as high blood pressure
• Trauma: such as a car accident that results in impact to the chest
• Congenital heart defects: including damaged heart valves
• Prolonged use of certain drugs: such as drugs containing ergotamine that are used to treat migraines and other conditions
• Radiation therapy: for cancer that is focused on the chest area (rare cause)

What Are the Risk Factors of Mitral Regurgitation?

• History of valve disease: including mitral valve prolapse or mitral valve stenosis
• Heart attack or heart disease
• Infections such as endocarditis or rheumatic fever
• Congenital heart disease
• Age: causing natural deterioration of the valve
• Use of certain medications: including drugs containing ergotamine (and similar medicines for migraines), cabergoline, pergolide (now off the market) and the appetite suppressants fenfluramine and dexfenfluramine (now off the market)

To diagnose your condition, your physician will start by taking your medical history and your family history of heart disease. Your physician will listen to your heart with a stethoscope and may recommend one or more diagnostic tests, including:

• Cardiac Magnetic Resonance Imaging (MRI): a noninvasive test that utilizes radio waves and magnetic fields to deliver a highly detailed assessment of the structure and function of the heart and its vessels 
• Chest X-ray: enables your physician to determine whether the left atrium or the left ventricle is enlarged — possible indicators of MR — and the condition of your lungs
• Echocardiogram: uses ultrasound (high-frequency sound waves) to assess the size of the heart's chambers, the movement of the heart valves, and the motion of the heart wall. It can also measure the cardiac output (the volume of blood pumped in one minute) and some of the pressures within the heart.
• Electrocardiogram (ECG): provides a picture of the electrical activity that causes the heart to beat and may detect rhythm disturbances or evidence of coronary heart disease or other conditions that can cause MR. It can also show evidence of other associated cardiac abnormalities.

Treatment of MR depends on the severity of the condition and if the condition is worsening.

Treatment may range from ongoing monitoring of a patient’s condition to surgery, as outlined below:

• Ongoing monitoring: Some patients with mild MR may not require treatment but may need to remain under a physician’s care for ongoing monitoring.
• Medications: Certain medications may be prescribed to alleviate some of the symptoms of MR, including edema, to prevent blood clots and/or to manage conditions, such as high blood pressure.
• Mitral valve repair or replacement: One of the many minimally invasive heart procedures performed by the affiliated cardiac surgeons at Memorial Hermann. In the most severe cases of MR, the flaps of the mitral valve become thick or stiff and fuse together, requiring surgery. Through a small incision in the right side of the patient’s chest, the surgeon repairs or replaces the defective valve.
• Mitral valve repair with MitraClip®: In addition to traditional surgical procedures, Memorial Hermann offers minimally invasive mitral valve repair with MitraClip®. Using this system, cardiologists deploy a tiny clip delivered by a catheter into the heart to repair the malfunctioning mitral valve.