4. Heart Valve Issues
Aortic valve disease and mitral valve disease are both conditions where the valves that are in charge of regulating the blood flow into the left side of the heart do not open wide enough. This is referred to as stenosis. In some cases, the valve does not close completely. When this occurs it allows blood to flow backward through the valve. This is called insufficiency or regurgitation.
When the valves become narrow the blood cannot flow freely into the heart and the pressure within the left ventricle will build up. This causes it to have to work harder and harder during each contraction. In addition, the left ventricle will dilate in order to allow more blood flow, but this will make the pumping action of the left ventricle less efficient. The increase in pressure will extend throughout the left atrium and into the pulmonary veins, which causes fluid to build up in the lungs.