Mitral stenosis

2021-08-02 01:04 PM

Mitral valve stenosis, symptoms can resemble those of other heart conditions or heart valve problems - mild or more severe heart rate increases can occur at any time, such as during exercise.

Define

Mitral stenosis is a problem in which the mitral opening is narrowed (stenotic). This causes the hole not to open properly, impeding blood flow from through the valve to the left ventricle. A narrow mitral valve can make you tired and short of breath, among a host of other problems.

The main cause of mitral stenosis is an infection in children called rheumatic fever, which is associated with streptococcal infection. Rheumatic fever - still common in developing countries, can cause scarring of the mitral valve.
 
Mitral stenosis in people of all ages is treatable. If uncontrollable, mitral stenosis can lead to serious cardiovascular complications.

Symptoms

You may have mitral stenosis and feel fine, or you may have only minimal signs and symptoms for decades. However, the problem, although mild, can suddenly get worse. See your doctor if you develop these symptoms of mitral stenosis:

Fatigue, especially during strenuous activity.

Shortness of breath, especially with exertion or when lying down.

Swelling in the legs or ankles.

Tachycardia - feeling of a fast fluttering heartbeat.

Frequent respiratory infections such as bronchitis.

Severe cough, sometimes with bloody sputum.

Rarely, discomfort or chest pain.

Mitral valve stenosis, symptoms can resemble those of other heart conditions or heart valve problems - mild or more severe heart rate increases can occur at any time, such as during exercise. Tachycardia may also be accompanied by other symptoms. Or it can also be triggered by pregnancy or stress, such as a respiratory infection or a heart infection.

Mitral valve stenosis, common symptoms include heart failure, a complication of mitral stenosis, and other cardiovascular diseases. In mitral stenosis, pressure in the heart then returns to the lungs, leading to fluid accumulation (congestion) and difficulty breathing.

Symptoms of mitral stenosis usually appear between the ages of 40 and 50 but can occur at any age, even in the early stages. Depending on the extent of the narrowing, infants or children with mitral stenosis may have no symptoms, may function easily, or may have difficulty breathing with physical activity.

Mitral stenosis may also present several signs. May include:

Heart murmur.

Pulmonary hemorrhage.

Irregular heartbeat (arrhythmia).

Pulmonary arterial hypertension.

Blood clot.

Call your doctor and make an appointment right away if you have symptoms such as fatigue or shortness of breath with physical activity, heart palpitations, or chest pain.

If you've been diagnosed with mitral stenosis but don't have symptoms, talk to your doctor about recommending follow-up.

Causes

The heart, the center of the circulatory system, consists of four chambers. The two atria, above, receive blood. The two ventricles below, pump blood.

Blood flows through the chambers of the heart, with the help of four heart valves. The valves open and close to let blood flow in only one direction through the heart:

Tricuspid.

Pulmonary valve.

Mitral valve.

Aortic valve.

Mitral valve - located between two chambers on the left side of the heart. The leaflets of the mitral valve connect to the myocardium through the annulus. Anchoring the mitral valves to the left ventricle is a ligament, like parachute cords, called the mastoid ligament.

The mitral valve is forced open when blood flows from the left atrium into the left ventricle. When all the blood has passed through the valve, the leaflets close to prevent blood that has just entered the left ventricle from flowing backward, in the wrong direction.
 
Defective heart valves, one of which does not either open or close completely. When the valve doesn't close tightly, blood can back up. Backflow through the valve is called open. When the valve becomes narrow and the blood flowing through it is limited, that problem is called stenosis.

Narrow mitral valve. Many factors can narrow the passage between the two left chambers of the heart, impeding blood flow to the left ventricle of the heart. Causes of mitral stenosis include:

Rheumatic fever. A complication of pharyngitis, rheumatic fever can damage the mitral valve, leading to mitral stenosis later in life. Rheumatic fever is the most common cause of mitral stenosis. It can injure the mitral valve in two main ways. Infections can cause the leaflets of the valve to thicken, limiting the valve's ability to open. Or infections can cause the mitral leaflets to stick a little together, preventing the valves from opening and closing properly. People with rheumatic fever can have both stenosis and mitral regurgitation.

Congenital heart defects. In rare cases, a baby is born with a narrow mitral valve and develops mitral stenosis early in life. Babies born with this problem often require heart surgery to repair the valve. Others are born with a damaged mitral valve that puts them at risk of developing mitral stenosis as they age. In most cases, doctors don't know why heart valves don't develop properly in babies or children, so it's not something that can be prevented.

Other causes. Rarely, blood clots or growths can block the mitral valve, similar to mitral stenosis. As we age, too much calcium can build up around the mitral valve, which is sometimes the cause of significant mitral stenosis. Radiation therapy to the chest and certain medications can also cause mitral stenosis.

Risk factors

Mitral stenosis is less common today than it was a few decades ago because the most common cause, rheumatic fever, has largely been ruled out. However, rheumatic fever remains a frequent problem in countries where antibiotic use is not common.

Risk factors for mitral stenosis are a history of rheumatic fever and recurrent infections. Radiation therapy to the chest can cause mitral stenosis. Other unusual causes of mitral stenosis include medications, such as the ergot preparations used for migraines.

Complications

Whatever the cause, blood is restricted in the same way that flow is restricted. In mitral stenosis, it is difficult for blood to flow from the left atrium to the left ventricle. Pressure builds up in the left atrium, and the chambers of the heart can expand. Blood can pool in the lungs, leading to lung congestion and difficulty breathing. In addition, left atrial dilatation may be prone to an irregular heartbeat called atrial fibrillation. In atrial fibrillation, the upper chambers (atria) of the heartbeat chaotically and ineffectively.

Like other heart valve problems, mitral stenosis can weaken the heart and reduce its pumping efficiency. A narrow mitral valve reduces the amount of blood that flows through the heart valve into the ventricles and out to the rest of the body.

Left untreated, mitral stenosis can lead to complications such as:

Heart failure. Heart failure is a condition in which the heart is damaged and cannot pump enough blood to meet the body's needs. Mitral stenosis interferes with blood flow through the heart and out of the heart to the rest of the body. In addition, pressure builds up in the lungs, leading to fluid accumulation. Eventually, blood flow to the right side of the heart leads to a buildup of fluid in the ankles or abdomen or both areas (edema).

Cardiac chamber dilation. The build-up of pressure due to mitral stenosis dilates the atria. At first, this change helps the heart pump more efficiently, but eventually, overall heart health often takes a toll. In addition, pressure can build up in the lungs and cause congestion and pulmonary hypertension.

Atrial flutter. In mitral stenosis, muscle fiber stretching and left atrial enlargement can lead to a heart rhythm abnormality called atrial fibrillation. In atrial fibrillation, the upper chamber of the left heart beats erratically and too quickly.

Blood clots. Left untreated, atrial fibrillation can lead to a blood clot forming in the upper left chamber of the heart. Blood clots from the heart can break off and travel to other parts of the body, causing serious problems. For example, a blood clot travels to a blood vessel in the brain and can cause a stroke. Transesophageal echocardiography can help determine if a blood clot forms in the heart when the mitral valve is narrow.

Jam. Another possible lung complication of mitral stenosis is pulmonary edema - a condition where blood and fluid back into the lungs. This causes congestion in the lungs, leading to shortness of breath and sometimes coughing up blood-tinged phlegm.

Tests and diagnostics

If you develop signs or symptoms of mitral stenosis - for example, if you experience sudden shortness of breath with mild exertion - your doctor may order several types of tests to make a diagnosis.

But your doctor will first ask about your medical history and do a physical exam. As part of the test, listen to your heart through a stethoscope. A narrow mitral valve causes an abnormal heart sound, called a heart murmur. Normally, heart valves open silently to allow blood flow. Mitral stenosis can make a distinct, strong sound followed by a murmur.

Also, to listen to the heart, the doctor listens to the lungs and breathing sounds. The doctor checks for lung congestion, a buildup of fluid in the lungs that can occur with mitral stenosis.

From the initial information, the doctor decides on the necessary tests to make a diagnosis.

Diagnostic tests and procedures

Common tests to diagnose mitral stenosis include:

Echocardiography. This test uses sound waves to create images of the heart. In an echocardiogram, sound waves are directed at the heart from a wand-like device (transducer) into the chest. Sound waves exit the heart and are reflected back through the chest wall and processed electronically to provide video images of the moving heart. An echocardiogram helps the doctor check the mitral valve. These images show the structure of the mitral valve and how it moves through the heart. Will it open wide to let blood flow through? Does it fully close? Ugly? With an echocardiogram, the doctor can also measure the speed and direction of blood flow through the valve.

Electrocardiogram (ECG). In this test, electrodes with wires (electrical) are attached to the skin to measure the electrical impulses emitted by the heart. The recorded pulse is a wave displayed on a screen or printed on paper. An electrocardiogram can provide information about heart rate and indirectly heart size. With mitral stenosis, certain parts of the heart may dilate and there may be atrial fibrillation, an irregular heartbeat. Your doctor may ask you to walk on a treadmill or ride a bicycle during an electrocardiogram, to see how your heart responds to exertion.

Follow Holter. A Holter monitor is a portable, wearable device that records an ECG continuously, usually for 24 to 72 hours. Holter monitoring is used to detect persistent irregular heartbeats that may accompany mitral stenosis.

X-ray. Chest X-ray images allow your doctor to check the size and shape of your heart to determine if your left atrium is dilated — a possible indicator of mitral stenosis. X-rays also help the doctor check the condition of the lungs. Narrow mitral valves can lead to blood backing up in the lungs, causing obstructions that are visible on radiographs.

Transesophageal echocardiography. This type of echocardiogram allows a closer look at even the mitral valves. The tube that runs from the throat to the stomach is located close behind the heart. In traditional echocardiography, the transducer is moved over the chest. In a transesophageal echocardiogram, a small transducer attached to the end of a tube is inserted down the esophagus. Because the esophagus is located close to the heart, it has a transducer, which provides a clear picture of the mitral valve and blood flow through it.

Cardiac catheterization. In this section, the tube is passed through a blood vessel in the arm or groin. The dye is injected through the catheter and the arteries become visible on the X-ray. This test gives your doctor detailed information about your heart health. Some catheters used in cardiac catheterization have miniature devices (sensors) that can measure pressure in the chambers of the heart, like the left atrium.

This test helps your doctor distinguish mitral stenosis from other heart conditions, including other problems of the mitral valve. Mitral regurgitation is a condition in which the mitral valve does not close tightly. Mitral valve prolapse is a disorder in which the mitral valve prolapse instead of closing tightly. These conditions may also require treatment.

If a diagnosis of mitral stenosis is received, these tests also help reveal the cause, identify the problem, and determine if the mitral valve can be repaired or replaced if necessary.

Treatments and drugs

Treatments to prevent permanent damage to the heart from mitral stenosis include medications and invasive procedures.

Invasive treatment for mitral stenosis is not always necessary immediately. If testing shows mild to moderate mitral stenosis and no symptoms, there is generally no need for immediate valve repair or replacement. Instead, the doctor will carefully check progress, monitoring the valve so that surgery can be performed as soon as the condition becomes severe. Some people never need anything, because they never develop severe mitral stenosis.

Medicine

There is no drug that can correct errors in the mitral valve. However, some medications can relieve symptoms by reducing the heart's workload and regulating the heart rate.

For example, your doctor may prescribe:

Diuretic. These medications can reduce fluid buildup in the lungs or elsewhere.

Blood thinners (anticoagulants). These medications help prevent blood clots from forming.

Antibiotics. Your doctor may recommend antibiotics before certain dental or medical procedures to reduce the risk of bacteria entering the bloodstream and causing an infection in the heart (endocarditis).

Your doctor may also prescribe medication to treat atrial fibrillation or other arrhythmias associated with mitral stenosis.

Tricks

Valve repair or replacement may be needed to treat mitral stenosis. Both surgical and non-surgical options are available.

Ball valve repair:

This procedure uses a catheter with a balloon attached. The doctor directs the catheter through a blood vessel in the arm or groin to the heart and into the mitral stenosis. Once in position, the balloon at the tip of the catheter will be inflated. The balloon pushes open the mitral valve and widens the orifice, improving blood flow. The balloon is then deflated and the catheter is guided back. Ballooning of the mitral valve may relieve mitral stenosis and its symptoms. But it may not be appropriate if both stenotic and regurgitated valves are present. It is also not performed if there is a blood clot in a chamber of the heart, because of the risk of blockage. Repeated procedures may be needed within 10 years.

Mitral valve surgery:

If there is non-mild regurgitation or if there is a valve problem other than mitral stenosis, surgery may be a better option than balloon repair. Surgical options include:

Valve repair (valvuloplasty). Using traditional surgical tools, cardiac surgeons can repair a leaflet separation and remove objects on or near the mitral valve. This makes it easier for the blood to pass. Repeated procedures may be needed if mitral stenosis develops again in the years following surgery.

Replace mitral valve. Most people with mitral stenosis who need surgery will have their mitral valve replaced. The surgeon removes the narrow mitral valve and replaces it with a mechanical or biological valve. Mechanical valves, made from metal, are durable, but carry the risk of blood clots forming on or near the valve. If you have a mechanical mitral valve replacement, you'll need to take an anticoagulant, such as warfarin (Coumadin) to prevent blood clots. Biological valves, which can be obtained from pigs, cows, or donors. Your doctor can discuss the risks and benefits of each type of heart valve.

Mitral valve surgery may include open-heart surgery. However, the use of less invasive techniques is increasingly available. For example, in a surgical robot, the surgeon sees a 3D image of the area being operated on and uses the controls. This method requires smaller incisions and a faster recovery time.

There may be a continued risk of arrhythmia, even after successful surgery for mitral stenosis. medication may be needed to reduce that risk.

Other procedures

In some cases, the surgeon may perform additional surgery at the time of the main surgery to try to keep the heart in a normal rhythm. This involves making a series of surgical incisions in the upper half of the heart (atria).

Prevention

The best way to prevent mitral stenosis is to prevent the most common cause, rheumatic fever. This can be done by making sure children see a doctor whenever there is a sore throat. If strep throat is left untreated, the infection can develop into rheumatic fever. Fortunately, sore throats are easily treated with antibiotics.