Faulty mitral valves are extremely common. For most people, this causes few problems. In others it can be life-threatening.

Mitral Regurgitation
Also known as mitral incompetence or mitral insufficiency, mitral regurgitation is a valvular heart disease in which one of the heart valves fails to close properly, causing blood to leak through the opening and go in the wrong direction.

People with a history of rheumatic fever, coronary artery disease, heart attack, or a hereditary connective tissue disorder, such as Marfan syndrome, are at increased risk of mitral regurgitation. Mitral regurgitation can lead to mitral valve prolapse, left ventricle enlargement, valve and heart muscle infections, such as endocarditis or myocarditits, or heart failure.

Mitral Stenosis
When the opening of the mitral valve narrows, blood flow is limited and the atrium has to work harder. This can potentially lead to heart failure. Mitral stenosis is most commonly a consequence of rheumatic fever, hardening of the leaflets with age, or certain congenital heart defects. Patients may not experience symptoms. Sometimes they may develop an abnormal heart rhythm such as atrial fibrillation.

Mitral Valve Prolapse (MVP)
This common condition can be caused by Barlow’s disease, which is an abnormality in the structure of the leaflets of the valves. It can also occur as an occasional consequence of aging, as the leaflets become less elastic. People with certain connective tissue diseases experience fibroelastic deficiency, a condition that affects valve function.

As the population ages, Paul Stelzer, MD, Professor of Cardiothoracic Surgery, is seeing more cases of aortic valve disease in older people.

"Aortic valves are kind of like car valves," he says. "Eventually, they just wear out."

Aortic valve diseases fall within two categories:

Aortic Stenosis
When the aortic valve opening narrows, it is harder for blood to push through to the aorta. The ventricle becomes overworked, its walls thicken, and the risk of heart attack or heart failure increases. The valves also become susceptible to infection. Symptoms include fatigue, difficulty breathing, chest pain, and fainting. People with a history of rheumatic fever and those born with certain valve conditions, such as a bicuspid aortic valve, are at higher risk. In older people, the cause is usually a buildup of calcium on the valve leaflets.

Aortic Regurgitation
Also known as aortic incompetence or aortic insufficiency, aortic regurgitation occurs when blood flows backwards through the aortic valve. People with heart-damaging infections such as rheumatic fever, high blood pressure, and certain birth defects, such as a bicuspid aortic valve, are at higher risk. If regurgitation becomes severe, heart failure may result.

The tricuspid valve is on the right side of the heart, between the right atrium and the right ventricle.

Tricuspid Regurgitation
Also known as tricuspid incompetence or tricuspid insufficiency, tricuspid regurgitation is a condition in which a leaky tricuspid valve causes blood to move backwards into the right atrium. This puts undue pressure on the atrium walls and the nearby veins, causing them to enlarge. An enlarged atrium can cause abnormal heart rhythms, such as atrial fibrillation. Untreated, tricuspid regurgitation can lead to symptoms of heart failure, including fatigue and swollen legs.

Tricuspid regurgitation is often seen in conjunction with problems on the opposite side of the heart, such as mitral valve disease or left ventricular dysfunction.

The pulmonary valve lies between the right ventricle and the pulmonary artery.

Pulmonary/Pulmonic Regurgitation
When the pulmonary valve leaks, the right side of the heart has to work harder, which can lead to heart failure. Causes include pulmonary hypertension, heart infections such as endocarditis and rheumatic fever, or congenital valvular heart disease.

Pulmonary/Pulmonic Stenosis
This valvular heart disease, which obstructs the flow of blood to the heart, is often discovered shortly after birth, but it can also be diagnosed in adults. Doctors listen for a prominent heart sound called a murmur. Children born with the congenital disorders Tetralogy of Fallot and Noonan's syndrome are at increased risk of pulmonary stenosis.