Health A-Z

Medical Content Created by the Faculty of the
Harvard Medical School

Heart Valve Problems

What Is It?

The heart has four valves — the aortic, mitral, tricuspid and pulmonary valves. Like valves used in house plumbing, the heart valves open to allow fluid (blood) to be pumped forward, and they close to prevent fluid from flowing backward. Human heart valves are flaps of tissue called leaflets or cusps.

Heart valve problems fall into two categories:

• Stenosis — The opening of the valve is too narrow, and this interferes with the forward flow of blood

• Regurgitation — The valve doesn't close properly. It leaks, sometimes causing a significant backflow of blood.

Heart valve problems can be congenital, which means present at birth, or acquired after birth. A heart valve problem is classified as congenital when some factor during fetal development causes the valve to form abnormally. Congenital heart valve disease affects about one in 1,000 newborns. Most of these infants have stenosis of either the pulmonary or aortic valve. Most of the time, a specific cause cannot be determined. However, researchers believe that many cases are caused by genetic (inherited) factors. This is because there is a considerably high risk (2% to 6%) of valve abnormalities in the parents and siblings of affected newborns, compared with the overall risk of less than 1% in the general population. In 2% to 4% of heart valve problems, the heart defect is related to health or environmental factors that affected the mother during pregnancy. These factors include diabetes, phenylketonuria, rubella infection, systemic lupus erythematosus (SLE or lupus) or drugs taken by the mother (alcohol, lithium, certain seizure medications).

A heart valve problem is acquired if it occurs in a valve that was structurally normal at birth. Some common causes of acquired heart valve problems include:

• Rheumatic fever, an inflammatory illness that may follow an untreated strep throat infection

• Endocarditis, inflammation and infection of the heart valves

• Idiopathic calcific aortic stenosis, a degenerative condition seen in the elderly, in which the aortic valve cusps become thickened, fused and infiltrated with calcium

• Syphilis

• High blood pressure ( hypertension )

• Arteriosclerosis

• Connective tissue disorders, such as Marfan's syndrome

Heart valve problems affect each valve in a slightly different way.

Aortic valveThe aortic valve opens to allow blood to pass from the left ventricle to the aorta, the massive blood vessel that directs oxygenated blood from the heart to the rest of the body. Disorders of this valve include:

• Congenital aortic stenosis — When a child is born with congenital aortic stenosis, the problem is almost always a bicuspid aortic valve, meaning the valve has two flaps instead of the usual three. In about 10% of affected newborns, the aortic valve is so narrow that the child develops severe cardiac symptoms within in the first year of life. In the remaining 90%, congenital aortic stenosis is discovered only when a heart murmur is found during a physical examination.

• Acquired aortic stenosis — In adulthood, aortic stenosis typically is caused by rheumatic fever or idiopathic calcific aortic stenosis. Some recent research suggests that the same processes that cause atherosclerosis in the arteries of the heart may contribute to the development of aortic stenosis. Aortic stenosis accounts for 25% of all heart valve problems in adults, and 80% of patients are male.

• Aortic regurgitation — In aortic regurgitation, the aortic valve does not close properly, allowing blood to flow backward into the left ventricle. This decreases the forward flow of oxygenated blood through the aorta, while the backflow into the ventricle eventually dilates (stretches) the ventricle out of shape. In adults, about two-thirds of cases of aortic regurgitation are caused by rheumatic fever, and 75% of patients are male.

Mitral valveThe mitral valve opens to allow blood to pass from the left atrium to the left ventricle. Disorders of this valve include:

• Mitral stenosis — Congenital mitral stenosis is rare. The typical adult patient is a woman whose mitral valve was damaged by rheumatic fever.

• Mitral regurgitation — As in mitral stenosis, the cause is often rheumatic fever, but the patient is usually an adult male. Mitral regurgitation can also result from heart attacks or any condition that changes the overall size and configuration of the left ventricle.

• Mitral valve prolapse — In this condition, the leaflets of the mitral valve fail to close properly. It is a puzzling disorder that tends to affect women between the ages of 14 and 30. The underlying cause is unknown, and the majority of patients never have symptoms.

Pulmonary valveThe pulmonary valve, or pulmonic valve, is located between the right ventricle and the pulmonary artery. It allows oxygen-poor blood to flow from the right side of the heart to the lungs for oxygenation. Disorders of this valve include:

• Congenital pulmonic stenosis — In the relatively few newborns with severe congenital pulmonic stenosis, the child develops heart failure or cyanosis (a bluish color to the lips, fingernails and skin) within the first month of life. In most cases, the valve is deformed, with two or three leaflets partially fused.

• Adult disorders of the pulmonic valve — In adults, the pulmonic valve most often is damaged because of pulmonary hypertension (abnormally high pressure within the blood vessels in the lungs), usually related to chronic obstructive pulmonary disease. Damage from rheumatic fever and endocarditis is relatively rare.

Tricuspid valveThe tricuspid valve allows blood to flow from the right atrium to the right ventricle. Disorders of this valve include:

• Tricuspid stenosis — This usually is caused by an episode of rheumatic fever, which often damages the mitral valve at the same time. Tricuspid stenosis is relatively uncommon in North America and Europe.

• Tricuspid regurgitation — Tricuspid regurgitation typically occurs because of pulmonary hypertension, but it also can be caused by heart failure, myocardial infarction, endocarditis or trauma.

The heart has four valves — the aortic, mitral, tricuspid and pulmonary valves. Like valves used in house plumbing, the heart valves open to allow fluid (blood) to be pumped forward, and they close to prevent fluid from flowing backward. Human heart valves are flaps of tissue called leaflets or cusps.

Heart valve problems fall into two categories:

• Stenosis — The opening of the valve is too narrow, and this interferes with the forward flow of blood

• Regurgitation — The valve doesn't close properly. It leaks, sometimes causing a significant backflow of blood.

Heart valve problems can be congenital, which means present at birth, or acquired after birth. A heart valve problem is classified as congenital when some factor during fetal development causes the valve to form abnormally. Congenital heart valve disease affects about one in 1,000 newborns. Most of these infants have stenosis of either the pulmonary or aortic valve. Most of the time, a specific cause cannot be determined. However, researchers believe that many cases are caused by genetic (inherited) factors. This is because there is a considerably high risk (2% to 6%) of valve abnormalities in the parents and siblings of affected newborns, compared with the overall risk of less than 1% in the general population. In 2% to 4% of heart valve problems, the heart defect is related to health or environmental factors that affected the mother during pregnancy. These factors include diabetes, phenylketonuria, rubella infection, systemic lupus erythematosus (SLE or lupus) or drugs taken by the mother (alcohol, lithium, certain seizure medications).

A heart valve problem is acquired if it occurs in a valve that was structurally normal at birth. Some common causes of acquired heart valve problems include:

• Rheumatic fever, an inflammatory illness that may follow an untreated strep throat infection

• Endocarditis, inflammation and infection of the heart valves

• Idiopathic calcific aortic stenosis, a degenerative condition seen in the elderly, in which the aortic valve cusps become thickened, fused and infiltrated with calcium

• Syphilis

• High blood pressure ( hypertension )

• Arteriosclerosis

• Connective tissue disorders, such as Marfan's syndrome

Heart valve problems affect each valve in a slightly different way.

Aortic valveThe aortic valve opens to allow blood to pass from the left ventricle to the aorta, the massive blood vessel that directs oxygenated blood from the heart to the rest of the body. Disorders of this valve include:

• Congenital aortic stenosis — When a child is born with congenital aortic stenosis, the problem is almost always a bicuspid aortic valve, meaning the valve has two flaps instead of the usual three. In about 10% of affected newborns, the aortic valve is so narrow that the child develops severe cardiac symptoms within in the first year of life. In the remaining 90%, congenital aortic stenosis is discovered only when a heart murmur is found during a physical examination.

• Acquired aortic stenosis — In adulthood, aortic stenosis typically is caused by rheumatic fever or idiopathic calcific aortic stenosis. Some recent research suggests that the same processes that cause atherosclerosis in the arteries of the heart may contribute to the development of aortic stenosis. Aortic stenosis accounts for 25% of all heart valve problems in adults, and 80% of patients are male.

• Aortic regurgitation — In aortic regurgitation, the aortic valve does not close properly, allowing blood to flow backward into the left ventricle. This decreases the forward flow of oxygenated blood through the aorta, while the backflow into the ventricle eventually dilates (stretches) the ventricle out of shape. In adults, about two-thirds of cases of aortic regurgitation are caused by rheumatic fever, and 75% of patients are male.

Mitral valveThe mitral valve opens to allow blood to pass from the left atrium to the left ventricle. Disorders of this valve include:

• Mitral stenosis — Congenital mitral stenosis is rare. The typical adult patient is a woman whose mitral valve was damaged by rheumatic fever.

• Mitral regurgitation — As in mitral stenosis, the cause is often rheumatic fever, but the patient is usually an adult male. Mitral regurgitation can also result from heart attacks or any condition that changes the overall size and configuration of the left ventricle.

• Mitral valve prolapse — In this condition, the leaflets of the mitral valve fail to close properly. It is a puzzling disorder that tends to affect women between the ages of 14 and 30. The underlying cause is unknown, and the majority of patients never have symptoms.

Pulmonary valveThe pulmonary valve, or pulmonic valve, is located between the right ventricle and the pulmonary artery. It allows oxygen-poor blood to flow from the right side of the heart to the lungs for oxygenation. Disorders of this valve include:

• Congenital pulmonic stenosis — In the relatively few newborns with severe congenital pulmonic stenosis, the child develops heart failure or cyanosis (a bluish color to the lips, fingernails and skin) within the first month of life. In most cases, the valve is deformed, with two or three leaflets partially fused.

• Adult disorders of the pulmonic valve — In adults, the pulmonic valve most often is damaged because of pulmonary hypertension (abnormally high pressure within the blood vessels in the lungs), usually related to chronic obstructive pulmonary disease. Damage from rheumatic fever and endocarditis is relatively rare.

Tricuspid valveThe tricuspid valve allows blood to flow from the right atrium to the right ventricle. Disorders of this valve include:

• Tricuspid stenosis — This usually is caused by an episode of rheumatic fever, which often damages the mitral valve at the same time. Tricuspid stenosis is relatively uncommon in North America and Europe.

• Tricuspid regurgitation — Tricuspid regurgitation typically occurs because of pulmonary hypertension, but it also can be caused by heart failure, myocardial infarction, endocarditis or trauma.