There are four valves in the normal heart. These are the Aortic valve, Mitral valve, Tricuspid valve, and Pulmonary valve. These serve like a doorway, controlling the blood flowing from chamber to chamber within the heart. There are many malfunctions that can occur with any one of the heart valves. Commonly known is regurgitation, stenosis, Mitral Valve Prolapse. Some valve problems can be congenital (primary) meaning one is born with it, while others may be due to injury or trauma, or may result from a flare-up of an existing disease (secondary).
Regardless of the cause, the disruption of the normal valve function can ignite a sequence of new complications, Congestive Heart Failure for instance. Additionally, the natural course of blood flow is likely to be disrupted since one of the functions of the valves is to regulate blood flow.
Here is a brief example:
Experiencing Rheumatic fever in childhood may result in a highly calcified mitral valve. The mitral valve opens to release blood from the left atrium to the left ventricle. A highly calcified mitral valve however, may harden or lose mobility and thus may not open completely, resulting in the left atrium not emptying completely. This may mimic a ‘backup’ of blood in the left atrium and over time begin to dilate. One of the physical symptoms often noticed with this problem is shortness of breath. This is because the blood leading into the left atrium comes from the pulmonary veins which carry oxygenated blood from the lungs.
The above mentioned example is not all-inclusive and only one of the many forms a calcified mitral valve may become problematic. Your physician may order an Echocardiogram to assess the status of a suspected valve disorder.
Please note that there are a plethora of valvular heart conditions.