Valve Disease (Valvular Heart Disease)

The human heart has four chambers, two on the right side and two on the left side.  The upper chambers are called atria and accept blood from large veins.   Blood is then passed to the lower main pumping chambers, called ventricles.  The right atrium receives oxygen-poor blood from the veins of the body, which flows to the right ventricle which pumps blood through the pulmonary artery to the lungs and becomes oxygenated.  Oxygenated blood then goes through the pulmonary veins into the left atrium and then flows into the left ventricle which pumps blood into the aorta, which delivers blood to the body.

Heart valves are tissue flaps that act like doors. They open to let blood flow through your heart, and then shut to keep the blood from flowing backward.  This is highly coordinated with each heartbeat.  The main function of the valves is to keep blood flowing in one direction through the heart’s chambers. A heart murmur is a sound that can be heard by a cardiologist using a stethoscope. It is due to blood flow in the heart.  It can be an innocent murmur not related to valve disease, or can indicate dysfunction of one or more of the heart valves.  An echocardiogram is the most commonly used test to evaluate heart valve function.  It is an ultrasound that allows a cardiologist to visualize the heart and all of its valves.

When a valve does not close properly and blood leaks backwards, the backflow is called regurgitation.  A small amount of regurgitation is usually well tolerated and might not ever worsen or cause a problem.  When a significant amount of regurgitation is present, the pumping chamber has to work much harder, pumping a larger amount of blood very inefficiently to try to get enough blood to go forward to meet the demands of the body.

When a valve does not fully open or is restricted, it is called valvular stenosis.  This usually is due to the valve tissue thickening, stiffening, or fusing together.  Mild stenosis is usually well tolerated, and might not ever worsen or cause a problem.  More severe valve stenosis narrows the opening that blood normally flows through, making it harder for the blood to be pumped through the valve.  The pumping chamber or ventricle ends up working much harder and too much pressure is put on the walls of the heart.

The human heart has four valves:

1)            The aortic valve

2)            The mitral valve

3)            The pulmonary or pulmonic valve

4)            The tricuspid valve.

Heart valve disease occurs when one or more of these valves do not work properly. The aortic valve allows blood to leave the heart’s main pumping chamber, and go into the aorta to be delivered to the body.  This opening between the left ventricle and aorta is circular and has three cusps, each relatively even in size.  It opens with each heartbeat.  The mitral valve has 2 cusps and opens between each heart beat allowing blood to flow from the left atrium into the left ventricle.  Similar to the aortic valve, the pulmonary valve has 3 cusps and allows blood to go from the right ventricle to the pulmonary artery.  The tricuspid valve has 3 cusps and allows blood to flow from the right atrium to the right ventricle.

Valves can degenerate with age and not properly close leading to regurgitation or they can stiffen with age leading to stenosis.  A number of valve structural problems can be present at birth. Valves might not form properly; they may not have enough tissue flaps, they may be the wrong size or shape, or they make lack an opening through which blood can flow properly.

Heart valve disease is common, affecting over 5 million individuals in the United States.  For some people, the condition will stay constant over their lifetime and never require treatment or intervention. For others, heart valve problems will worsen over time, eventually requiring medication, medical procedures, or even surgery to repair or replace the defective valve. Usually, valve problems in adults are more serious when on the left side of the heart, although, on occasion, severe tricuspid or pulmonic valve problems can be significant.

Degenerative valve disease, the most common form of valvular heart disease in industrialized nations, is associated with aging, and is an emerging health problem with broad consequences. Increasing age is the greatest risk factor for valve disease and an estimated one in eight people age 75 years or older have at least moderate heart valve disease.

Drug Therapies

People with heart valve disease may be prescribed medicines to treat heart failure, lower blood pressure, or prevent irregular heartbeats.  Since several valve diseases or defects make people susceptible to blood clots, blood thinning drugs are sometimes recommended. These medications are required for people who have undergone surgery and now have one or more man-made valves.  For many years, patients with various heart valve problems were instructed to take antibiotic prophylaxis before dental work and other medical procedures in order to reduce the risk of endocarditis.  These recommendations have changed, and far fewer patients now need to take these prophylactic antibiotics.  If you have a heart valve abnormality but are not sure if you still need to take antibiotics prior to dental visits and other medical procedures, please check with your cardiologist.

Natural History

Heart valve disease is usually a lifelong condition. Over time, the problem may require more than medications can offer. In these cases, valve repair or replacement may be indicated. Patients with heart valve disease are routinely evaluated and followed by cardiologists. Once you have undergone such a surgical procedure for valve disease, you may still need certain medications, and will require regular checkups for the rest of your life.

Technical Considerations

Valve repair or replacement may be recommended for advanced valve disease, or in people with less advanced disease but at high risk of damaging their heart without surgical intervention.

Mitral Regurgitation

Based on better outcomes, mitral valve repair is recommended over mitral valve replacement for the majority of patients. Mitral regurgitation requiring surgical intervention should be surgically repaired if technically feasible. Newer, non-surgical techniques to repair mitral regurgitation are being developed but are still considered experimental.

Aortic Stenosis and Aortic Regurgitation

Aortic valve problems requiring surgical intervention almost always indicate a valve replacement.  Newer, non-surgical techniques to implant a new aortic valve for some patients with aortic stenosis are being developed but are still experimental.  You should talk to your cardiologist and cardiac surgeon about the pros and cons of different approaches to your problem.

Tissue or mechanical valve?

Patients who require valve surgery where repair is not feasible may be offered a metal valve or a tissue valve.  Tissue valves offer the advantage of not requiring the use of blood thinners after implantation, but will not last as long as a mechanical valve.  This means that if a tissue valve is implanted in a young individual, a repeat valve replacement surgery is likely during that patient’s lifetime.  The decision to implant a tissue valve needs to include patient age and patient lifestyle issues.  The guidelines recommend a patient age of 65 years as the threshold for implantation of a tissue valve in the aortic and mitral positions. The guidelines make an allowance for patient preference to recommend a bio prosthesis in a patient under 65 years of age. Improvements in durability of newer bio prosthetic tissue valves are leading them to last longer, thus younger patients are opting for tissue valves more often.

Non-surgical techniques

Heart valves that don’t open fully due to stenosis may be treated with a less invasive catheter procedure called balloon valvuloplasty. It’s similar to balloon angioplasty which is used to open a clogged artery. It is not a cure, but using a balloon to increase blood flow through a narrowed heart valve can help relieve many of the symptoms of valve disease. In some infants and children, valve stenosis is caused by a congenital defect that can be repaired by a single balloon valvuloplasty.

Although not widely available, there are some newer surgeries that utilize less invasive means to access the valves. These procedures use smaller incisions, cause less pain, and speed recovery time. Some cardiologists and cardiac surgeons are exploring these new procedures, but they are still largely experimental.

Valve disease and pregnancy

Usually, mild-to-moderate heart valve disease during pregnancy can be managed with conservative measures such as medications and bed rest. Severe heart valve disease, however, can increase risks during pregnancy or labor. An examination and assessment of heart function will determine whether a woman will be able to tolerate the stresses on the heart during pregnancy, labor, and delivery. Women with severe valve disease should talk to their doctor about valve repair or replacement before getting pregnant.

Charles A. Shoultz, III, M.D., F.A.C.C.   •   Rodney A. Brown, M.D., F.A.C.C.
William R. Pitts, M.D., F.A.C.C.   •   Donald S. (Buck) Cross, M.D., F.A.C.C. • Andrew K. Day, M.D., F.A.C.C.
Sherwin F. Attai, M.D., F.A.C.C.   •   Shawn J. Skeen, M.D. F.A.C.C.   •   Harvey R. Chen, M.D. F.A.C.C.
Adam M. Falcone, M.D., F.A.C.C.   •   Brian C. Barnett, M.D., F.A.C.C.   •   Timothy N. Ball, M.D., F.A.C.C.   •   Clay M. Barbin, M.D., F.A.C.C.

Diplomates, American Board of Internal Medicine,
Cardiovascular Disease, Interventional Cardiology, Clinical Cardiac Electrophysiology