Four heart valves control how blood flows in and out of your heart. The valves are like one-way doors that keep blood flowing in the right direction.
Your mitral valve separates your left atrium and left ventricle. This valve opens to let blood from your lungs out of your left atrium and into the left ventricle. The valve closes to keep blood from running back into your left atrium.
Mitral stenosis is when the mitral valve doesn't open all the way so it's hard for blood from your lungs to get out of the left atrium. Blood pressure in your left atrium and your lungs builds up.
Certain disorders can cause the flaps on the mitral valve to get stiff and thick
The most common cause is untreated rheumatic fever, but infants can be born with it
Mitral stenosis may not cause symptoms for a long time
Severe stenosis can cause symptoms, such as shortness of breath, or an abnormal heart rhythm, such as atrial fibrillation
Doctors can hear a heart murmur through a stethoscope and do echocardiography to diagnose mitral stenosis
Treatment can include medicines and surgery
If you have mitral stenosis, pregnancy can make heart failure develop quickly.
(See also Overview of Heart Valve Disorders.)
Rheumatic fever in childhood—but mitral stenosis will not occur if rheumatic fever is prevented by promptly treating strep throat with antibiotics
Wear and tear in the valve with old age
Sometimes, people are born with mitral stenosis
Mild mitral stenosis doesn't usually cause symptoms.
Severe mitral regurgitation can cause heart failure, which may cause you to:
Atrial fibrillation may cause:
Once symptoms start, people become severely disabled in about 7 to 9 years. Children born with mitral stenosis often don’t live more than 2 years unless they have surgery.
Doctors suspect mitral stenosis by listening to your heart with a stethoscope. Doctors use echocardiography (an ultrasound of your heart) to find out how narrow the valve is.
Doctors also do tests such as:
If you don't have symptoms, you don't need treatment.
If you have symptoms, doctors will treat you with medicines to:
If the medicines don't control the symptoms enough, the valve may be repaired or replaced.
When possible, doctors try to repair the valve, a procedure called a valvuloplasty. During valvuloplasty, the doctor inserts a thin, hollow tube (catheter) through a vein or artery into your heart. The doctor inflates a balloon on the tip of the catheter. The balloon pushes the valve open. Sometimes doctors repair the valve during heart surgery.
If your valve cannot be repaired, it can be replaced with:
If you get a mechanical valve, you'll need to take blood-thinning medicine for the rest of your life, but the valve may last several decades. If you get a bioprosthetic valve, you'll need to take the medicine for only a few months, but the valve will last only 10 to 12 years.
People with damaged or replaced valves sometimes need antibiotics to prevent heart valve infection, such as when they: