Structural Heart Disease Overview
Structural heart disease describes a condition in which a patient has inherited (congenital) or acquired defects or both, compromising the integrity of the heart’s valves or chambers. These can range from a hole between the top two chambers, as in atrial septal defect or patent foramen ovale; valvular heart disease, such as aortic stenosis/regurgitation or mitral stenosis/regurgitation; or closure of certain pockets of the upper chambers.
Two forms of congenital heart disease include the larger and more complicated atrial septal defect (ASD), or a smaller hole in the wall between the two upper chambers of your heart, a patent foramen ovale (PFO). Both of these deficits can lead to clinical consequences, which may include stroke or right heart failure.
Valvular heart disease occurs when your heart’s valves do not work correctly, characterized by either damage or a defect in one of the four heart valves or supporting apparatus.
The mitral and tricuspid valves control the flow of blood between the upper chambers (atria) and the lower chambers (ventricles). The pulmonary valve controls the flow of blood from the heart to the lungs, and the aortic valve regulates blood flow between the heart and the aorta. Failure of normal mitral and aortic valve function may occur insidiously over many decades.
Valves function normally when blood flows with proper force and direction through the heart. Valvular heart disease is characterized by a valve that is too narrow (stenosis) or when valves are unable to close completely, thus allowing the blood to leak backward across the valve (incompetency, insufficiency or regurgitation). In general, valvular heart disease causes the heart to work harder to circulate the proper amount of blood throughout the body.
Structural heart disease has a variety of causes, some present at birth (congenital) and others acquired later in life. High blood pressure, atherosclerosis , heart attacks, cardiomyopathy and aging may severely affect the heart and valves as well as some migraine and diet medications. Some infections and disorders that may lead to heart disease include:
- Rheumatic fever, in which a streptococcal bacteria affects the mitral valve, causing it to become narrowed (most often) or leaky. Mitral Stenosis is seen much less frequently than in prior decades.
- Endocarditis, a potential life-threatening infection in which bacteria attaches to the heart valves, destroying the valve and leaving scar tissue behind. These germs most often enter the body through improper sterilization during surgery or through poor dental hygiene.
- Carcinoid tumors, rheumatoid arthritis, lupus or syphilis
Other causes include myxomatous degeneration, which is a weakening of valve tissue caused by connective tissue changes; calcific degeneration, which involves valves thickening due to a buildup of calcium on the aortic or mitral valves; and congenital defects involving an irregularly shaped aortic valve or narrowed mitral valve.
Many patients do not exhibit symptoms in the early stages of structural heart disease, but signs can occur suddenly and increase in severity as the disease develops. Many of the symptoms are similar to those related to congestive heart failure, such as shortness of breath even with limited activity and swelling of the feet, ankles, hands or abdomen.
The main sign of valvular heart disease is an unusual heartbeat sound called a heart murmur. Other symptoms include:
- Rapid or irregular heartbeat or pulse
- Dizziness or fainting (with aortic stenosis)
- Fever (with endocarditis)
- Rapid weight gain
Scientists do not know for certain why congenital heart disease occurs, but it tends to run in families and often occurs with other genetic problems, such as Down’s syndrome. Some conditions during pregnancy may also increase the risk, most notably a rubella (German measles) infection or alcohol and drug use.
Older people are most at risk of developing valvular heart disease, based on estimates that 1 of 8 people aged 75 or older will suffer at least a moderate form of the condition. Also, people who have a history of endocarditis, rheumatic fever, heart attack or heart failure are more at risk. High blood pressure, high cholesterol, smoking, diabetes, obesity, lack of physical exercise and a family history of heart disease are other major risk factors.