Heart Valve Disease Diagnosis

  • Diagnosis

    Heart valve disease is a problem with one or more of the valves that help keep the blood flowing in a forward direction through the heart. It's one of the most common forms of heart disease, affecting about five million Americans. Your heart is a fist-sized muscle that pumps blood through a network of vessels to all parts of your body. It is made up of four chambers: the upper chambers, or the left and right atria, and the lower chambers, or the left and right ventricles. Each chamber is closed off by a valve with thin flaps of tissue (leaflets) that open to allow blood to flow forward, and then close to prevent it from flowing backward.

    Heart valve disease most commonly affects the mitral and the aortic valves, which are located on the left side of the heart. The five most common types of heart valve disease are mitral valve prolapse, mitral stenosis, mitral regurgitation, aortic stenosis, and aortic regurgitation Figure 01.

    Click to enlarge: The Heart and its valves

    Figure 01. The Heart and its valves

    Heart valve disease can result when the valves are damaged or weakened Table 01. The type of heart valve disease that occurs depends on the affected valve and how much bloodflow is disrupted. The forward movement of bloodflow can be affected in two ways: it either builds in a heart chamber when the valve does not open completely (stenosis), or it leaks backwards when the valve does not close completely (regurgitation). A valve can have stenosis and regurgitation at the same time. In all cases, the heart has to work harder to maintain bloodflow. Over time, the extra workload causes the heart to weaken, making it unable to move blood in an efficient manner.

    Mitral valve prolapse (MVP)—also known as the “click-murmur” syndrome because of the sounds it makes through a stethoscope—occurs when the leaflets of the mitral valve become enlarged and can't close properly. When these leaflets are enlarged, they often bulge into the atrium as the heart contracts, disrupting bloodflow. The mitral valve may also become displaced as the fibrous strings supporting the leaflets (chordae) become inflamed and stretched out.

    Although its cause is not known, mitral valve prolapse is generally a condition in which the valve tissues become weak, flabby, and covered with starchlike deposits (myxomatous degeneration).

    Mitral stenosis occurs when the leaflets become scarred, rigid, and covered with hardened tissue and calcium deposits. When this happens, blood can’t flow forward easily, and pressure and fluid build-up are transmitted back to the lungs. This can lead to shortness of breath and, over time, congestive heart failure—a condition where the heart can’t pump adequate amounts of blood. The primary cause of mitral stenosis is rheumatic fever, an autoimmune disease of childhood that begins with strep throat and affects many tissues in the body, especially the heart valves.

    With mitral regurgitation (also called mitral insufficiency), the mitral valve cannot close properly, and blood leaks backward into the left atrium. Mitral regurgitation results when the muscles that control the closing of the valve malfunction, the strings (chordae) that support the leaflets rupture, or when the valve itself degenerates. Mitral valve prolapse, coronary artery disease, buildup of calcium deposits on the valve, injury to the muscles that support the valve, and connective tissue diseases such as lupus or Marfan syndrome or others can also lead to mitral regurgitation.

    Aortic stenosis occurs when the leaflets are misshapen. The aortic valve controls the flow of blood from the left ventricle into the aorta, your body's main artery and blood supplier. When the shape of the aortic valve's leaflets is distorted, the valve narrows, and bloodflow is slowed. About 1 in 20 people are born with only two leaflets instead of the standard three. Known as “bicuspid aortic valve,” this condition can eventually cause aortic stenosis. Although aortic stenosis can also be caused by rheumatic fever, this is rare. The condition is more likely to be caused by age-related degeneration and calcification of the aortic valve, making older people especially prone to aortic stenosis.

    Aortic regurgitation occurs when the valve cannot close properly, and blood leaks back into the left ventricle. Aortic regurgitation can result when the leaflets are deformed, or when the area where the aorta connects to the valve (aortic ring) widens. The two most common causes of leaflet deformity are a bicuspid aortic valve (two leaflets instead of the standard three) and bacterial endocarditis, a serious infection that damages heart valves. The exact cause of aortic ring widening is unknown. However, it may be related to connective tissue disorders, or to ankylosing spondylitis—a condition that causes pain and inflammation in the joints between the spine and pelvis, and between the vertebrae of the spine. Aortic stenosis can also lead to aortic regurgitation.

    Table 1.  Types and Causes of Heart Valve Disease

    Type Definition Cause(s)
    Mitral valve prolapse Tissue flaps of the mitral valve bulge, impairing bloodflow to the left atrium Myxomatous degeneration: a condition that causes valve tissues to become weak and flabby and covered with starch deposits Coronary artery disease Marfan syndrome: a disease of the body's connective tissue that causes joint dislocation and deformity.
    Mitral stenosis A narrowing of the mitral valve that occurs when the leaflets become scarred and rigid. Forward bloodflow is impaired, so pressure and fluid are transmitted back to the lungs. Rheumatic fever: a childhood bacterial infection that begins with strep throat and causes scarring of the valves Connective tissue disorders Tumors
    Mitral regurgitation The mitral valve cannot close properly and blood leaks backward into the left atrium. Rheumatic fever Mitral valve prolapse Coronary artery disease A buildup of calcium deposits on the valve Injury to muscles supporting the valve Connective tissue disease, including lupus and Marfan syndrome, and unknown causes
    Aortic stenosis Valve leaflets are distorted, causing valve narrowing and bloodflow impairment. Bicuspid aortic valve: (only two valve leaflets instead of the normal three) Calcium deposits and fibrous tissue buildup on leaflets Rheumatic fever
    Aortic regurgitation Valve cannot close properly, and blood leaks back into the left ventricle. Bicuspid aortic valve Endocarditis (an infection that causes the lining of the heart and valves to become inflamed) Rheumatic fever Connective tissue disorders Aortic stenosis

    In most patients, mitral valve prolapse (MVP) produces no symptoms. However, some people experience mild symptoms such as fatigue, shortness of breath, or sharp chest pain. The symptoms of heart valve disease vary depending on the valve affected and how bloodflow is disrupted. Often, symptoms develop gradually as the heart becomes increasingly taxed from its extra workload; mitral stenosis, mitral regurgitation, aortic stenosis, and aortic regurgitation may take decades to produce symptoms. A small number of patients with mitral valve prolapse may also develop tachycardia (rapid heartbeats). If mitral valve prolapse causes substantial valve leakage (regurgitation), it may cause symptoms of congestive heart failure.

    Mitral stenosis can cause shortness of breath with any sort of effort or activity, fatigue, and heart palpitations. In many people, symptoms don’t appear until the valve narrowing is severe. Shortness of breath is caused when the increased pressure needed to fill the left ventricle puts pressure on the blood vessels of your lungs. If your lungs have filled with fluid, you may cough up blood or bloody mucus. Some people also become quite hoarse if the pressure builds to the point where the left atrium presses on the nerves surrounding the vocal chords.

    Mitral regurgitation can cause fatigue, palpitations, and shortness of breath. You may experience more severe symptoms depending on when the condition occurs. Because the left ventricle adjusts to the extra volume of blood being pumped by your heart, it may take years before you notice any symptoms. Whether or not mitral regurgitation is a long-standing problem or appears suddenly seems to dictate the type of symptoms you'll have. If your condition is mild, it’s common to have no symptoms at all. Over time, however, the leakage places extra pressure on your lungs, resulting in fatigue, palpitations, and shortness of breath with effort, when lying down, or during sleep. If mitral regurgitation comes on suddenly, it can cause severe shortness of breath at rest, and shock.

    Aortic stenosis can cause chest pain that worsens with exercise or appears after exercise; fainting, and shortness of breath. These symptoms manifest as the condition worsens and the aortic valve becomes severely narrowed. Chest pain occurs because your heart has to pump harder to move the blood through the valve, creating a greater demand for oxygen than the blood can supply. Fainting is usually due to exertion; this causes your body's blood vessels to relax, lowering your blood pressure. In aortic stenosis, your heart isn't able to pump enough blood to offset this drop in blood pressure. Hence, bloodflow to your brain is reduced, causing you to faint.

    As aortic regurgitation becomes severe, symptoms such as fatigue, dizziness, and shortness of breath with effort, when lying down, or suddenly during sleep will appear. You might also experience ankle swelling, or rarely, chest pain with exertion or when at rest. It’s also common to notice a pulse in the neck when lying on the left side, and heartbeats that feel premature.

    Your risk for heart valve disease depends on a number of varying factors.

    • Gender. Mitral valve prolapse occurs more often in women than men, possibly because a woman's mitral valve is naturally large in relation to the left ventricle. Conversely, aortic stenosis and aortic regurgitation affect more men than women.
    • Age. Aging is a risk factor for aortic stenosis and mitral stenosis. This is because the natural buildup of calcium deposits on the leaflets that occurs as one ages can lead to stenosis. Aging also plays a role in mitral regurgitation.
    • Rheumatic fever in childhood. Rheumatic fever in childhood is the most common risk factor for mitral stenosis.
    • Genetics. Mitral valve prolapse tends to run in families. In addition, up to 1% of Americans are born with a bicuspid aortic valve, which is a major risk factor for aortic stenosis.
    • Use of Phen-Fen. Prior use of this diet combination, which is now off the market, is associated with a greater risk for aortic or mitral regurgitation. In addition, having used the drug for more than four months appears to raise the risk for the development of valve disease.

    Symptoms such as shortness of breath or your heart skipping a beat may suggest a heart valve problem to your doctor. Your primary care doctor may discover that you have heart valve disease because you are experiencing these symptoms. Other times, heart valve disease is discovered accidentally during a routine examination. If your disease is serious, you may be referred to a heart specialist (cardiologist) or a surgeon for treatment. However, your primary care doctor will likely be the one monitoring your condition.

    Your doctor will take a complete medical history to determine if you have any symptoms—such as fatigue and palpitations—that point to valve disease. Symptoms of valve disease are often vague and appear slowly. Other times, they come on very suddenly. That’s why it’s important to provide your doctor with as much information as possible. Be prepared to explain your exact symptoms, including the mildest (such as fatigue) or most severe (shortness of breath or chest pain while resting). Information about when and how symptoms first appeared is also important.

    A physical examination is one of the most important ways to diagnose heart valve disease. Normally, blood flows through the valves without making any noise. When a valve is damaged in any way, bloodflow will make a “whooshing” sound as it is forced through a narrowed opening or leaked backward; this is referred to as a “murmur.” Your doctor can determine if you have a murmur by listening to your heart with a stethoscope. Many types of valve diseases have characteristic sounds that help distinguish them. Your doctor will also consider where in the chest the murmur is the most distinctive, the timing of the murmur in relation to other normal heart sounds, and the presence or absence of symptoms. Remember that heart murmurs don't always indicate disease and can be present in perfectly healthy people.

    In addition to listening to your heart, your doctor will take your blood pressure and pulse rate. Both of these help to rule out other forms of heart disease as well as additional reasons for abnormal heart sounds.

    At least one of three tests will be done to confirm a valve disease diagnosis: a chest x-ray, an electrocardiogram (ECG), or an echocardiogram.

    • Chest x-ray. Valve diseases cause the heart to work harder to keep blood flowing. As a result, the heart thickens and enlarges over time. A chest x-ray can show whether or not any area of your heart has become enlarged. Although an enlarged heart may indicate another form of heart disease, it can point your doctor in the right direction. A chest x-ray can also show signs of calcium or tissue deposits on the valve leaflets.
    • Electrocardiogram. An electrocardiogram (ECG) is a test that records the electrical impulses of the heart. It can show any type of heart rhythm disturbances.
    • Echocardiogram. The most specific test for confirming heart valve disease is an echocardiogram. This procedure uses sound waves that are transmitted to the heart, and is essentially the same technology used in an ultrasound to observe a fetus in pregnant women. The echoes are produced when the waves are reflected back and turned into images by an instrument called a transducer. An echocardiogram provides very specific information about the size of the heart's chambers, the valve movements (which show whether they are closing and opening properly), and any changes in the blood vessels and other structures in and around the heart. One part of the echocardiogram, known as a “Doppler,” measures the speed and quality of the bloodflow, and can pinpoint stenosis or regurgitation.

    Your doctor may want to perform an extra procedure known as cardiac catheterization if other tests haven't provided enough information about your valve disease, or if surgery is being planned as treatment. Cardiac catheterization is a test that involves inserting a thin tube into your heart through a blood vessel. A dye is then injected into the tube so that the heart and bloodflow can be seen on x-ray. Catheterization can also be used to measure blood pressure within your heart, and to determine if blockages exist in the coronary arteries.

    Heart valve disease can increase the risk for a serious, life-threatening infection of the heart and valve linings called endocarditis. If you're at risk, your doctor may recommend that you take an antibiotic before certain dental and surgical procedures. Endocarditis is an infection that affects the lining of the heart and valves. It occurs when bacteria that reside normally in other parts of the body, such as the mouth, and upper respiratory and urinary tracts, travel through the bloodstream and settle in the heart. Endocarditis is twice as common in men over the age of 50 than in women, and rarely occurs when the valves are healthy. Certain dental and surgical procedures can stimulate the release of these bacteria. These procedures include:

    • Teeth cleaning or extraction
    • Examination of the respiratory tract with a bronchoscope (a hollow tube with a lens and eyepiece)
    • Gallbladder or prostate surgery
    • Examination of the digestive tract with a flexible viewing tube (sigmoidoscopy)

    Some people with heart valve disease and a history of rheumatic fever may need to take an antibiotic to prevent future attacks. Although rare in America and other Western countries, rheumatic fever is an important cause of several types of common valve diseases. If you’ve had rheumatic fever as a child and are younger than 35 years of age, your doctor may recommend that you take an antibiotic to prevent future episodes.

  • Prevention and Screening

    Heart valve disease can increase the risk for a serious, life-threatening infection of the heart and valve linings called endocarditis. If you're at risk, your doctor may recommend that you take an antibiotic before certain dental and surgical procedures. Endocarditis is an infection that affects the lining of the heart and valves. It occurs when bacteria that reside normally in other parts of the body, such as the mouth, and upper respiratory and urinary tracts, travel through the bloodstream and settle in the heart. Endocarditis is twice as common in men over the age of 50 than in women, and rarely occurs when the valves are healthy. Certain dental and surgical procedures can stimulate the release of these bacteria. These procedures include:

    • Teeth cleaning or extraction
    • Examination of the respiratory tract with a bronchoscope (a hollow tube with a lens and eyepiece)
    • Gallbladder or prostate surgery
    • Examination of the digestive tract with a flexible viewing tube (sigmoidoscopy)

    Some people with heart valve disease and a history of rheumatic fever may need to take an antibiotic to prevent future attacks. Although rare in America and other Western countries, rheumatic fever is an important cause of several types of common valve diseases. If you’ve had rheumatic fever as a child and are younger than 35 years of age, your doctor may recommend that you take an antibiotic to prevent future episodes.

Recommended Reading

Meet the Pharmacists

I'm Beth Isaac, PharmD. Welcome to PDR Health!

Check out my latest post on cholesterol drugs.

Heart Valve Disease Related Drugs