The heart has four valves located at the openings of the four heart cavities (right and left atria, right and left ventricles). These valves force blood to flow in a single direction through the heart by opening and closing with each heart contraction.
Pressure changes in front of and behind the valves force them to open like swinging doors and then to seal back closed to prevent blood from flowing back into the cavity.
There are four heart valves :
Coronary valve disease is diagnosed in two cases:
When the valve is stenotic (valvular stenosis), the valve opening is smaller than normal and the heart has to do extra work to pump blood through this opening. The conditions in this case are tricuspid stenosis, pulmonary stenosis, mitral stenosis or aortic stenosis.
When the valve regurgitates blood or closes improperly (valve regurgitation or failure), the valve does not seal when closed; blood then backs up against the normal flow. In this case, the various conditions include tricuspidal regurgitation (failure), pulmonary regurgitation (failure), mitral regurgitation (failure), or aortic regurgitation (failure).
Heart valve diseases are grouped according to the diseased valve, the type (stenosis or regurgitation) and the severity of the problem. The most common cardiac valve diseases are found in the aortic valve and the mitral valve. Tricuspid and pulmonary valve diseases are a lot more rare.