Disorders related to abnormal heart valve functions fall into two main groups. The first group includes disorders that cause narrowing of the valve, during which the process of opening and closing fail, and obstruct the forward flow of blood called stenosis. This condition usually occurs when the affected valves have become inflamed or calcified and may also be the result of a congenital defect.
The second group of valve disorders includes those in which the valves fail to close properly or completely, causing a reverse leakage, or regurgitation, of blood. These valves are insufficient. Backward leakage of blood may result from coronary heart disease, rheumatic heart disease or bacterial or viral infections.
Aortic Stenosis
Aortic stenosis may be present from birth or may be secondary to degeneration of the cusps of the valve due to unknown causes. Rheumatic heart disease can also cause this progressive degeneration of the aortic valve.
According to MayoClinic.com, narrowing of the aortic valve limits the heart’s output. The extra work required to pump blood through a narrowed outlet leads to enlargement of the left ventricle. There are few, if any, symptoms of this abnormal function resulting from aortic stenosis until it reaches a later stage of the disease. When symptoms eventually appear, they usually include breathlessness during exertion, faintness and angina or chest pain.
Aortic Insufficiency
Aortic insufficiency is a less common heart valve disorder that creates a significant amount of stress on the left ventricle, causing it to expand as any muscle will when it is overworked. According to the U.S. National Library of Medicine, for the heart to eject the amount of blood required by the body, the rise in blood pressure with each contraction has to be much higher than normal. However, because blood can flow back into the heart, the pressure then collapses to an unusually low level. This “collapsing pulse” is a trademark of aortic insufficiency.
Mitral Stenosis
In mitral stenosis, the cusps of the valves become thickened and often have a deposit of clotted blood called a thrombus on their upper surfaces. According to the Merck Manual, this narrowing of the valve eventually diminishes tolerance to physical activity and causes breathlessness and fatigue, even when an individual is at rest.
A typical sign seen in people with mitral stenosis and rheumatic heart disease is “mitral facies," a purple-pink tinge to the cheekbones and lips. A related problem is an accumulation of fluid in the lungs called pulmonary edema, which can eventually lead to heart failure.
Mitral Regurgitation
An insufficient mitral valve can have many causes, the most common one being a condition known as mitral regurgitation or, essentially, floppy valves. The valves do not close entirely, allowing blood to flow backward into the atrium. This defect may result in congestive heart failure from an accumulation of fluid in the lungs and heart.
Some people have a condition known as mitral valve prolapsed, often the cause of mitral insufficiency or mitral regurgitation. According to the U.S. National Library of Medicine, “One out of three cases of chronic mitral regurgitation are caused by rheumatic heart disease, a complication of untreated strep throat that is becoming less common.”
