Aortic Stenosisheart vlve withlabels

The aortic heart valve allows for the unidirectional ejection of oxygenated blood from inside the heart (left ventricle) to the systemic circulation. Adequate functioning of the aortic valve is dependent on its complete opening, which allows the unobstructed passage of blood, and tight closure (after ejection of blood) which prevents back flow into the heart. The progressive narrowing of the aortic valve is referred to as aortic stenosis (AS).The tissues forming the valve leaflets become stiffer, narrowing the valve opening and reducing the amount of blood that can flow through it. If the narrowing is mild, the overall functioning of the heart may not be reduced. However, the valve can become so narrow (stenotic) that heart function is reduced, and the rest of the body may not receive adequate blood flow.

Causes:

  • Rheumatic Heart Disease (secondary to rheumatic fever)
  • Congenital Defects (bicuspid valve): found in up to 2% of the general population. One of the most common defects is a bicuspid valve.  Anatomically correct valves have three flaps or leaflets but a bicuspid valve only has two flaps.
  • Calcium build up on the valve (scarring of the aortic valve in the elderly that occurs for unknown reasons)

The principal problem with aortic stenosis is obstruction to blood flow. Those with rheumatic heart disease, or bicuspid valve, can develop the symptoms of AS most commonly between the age of 40 and 60. With an increase of obstruction to blood flow (through the stenotic valve), the heart attempts to compensate by enlarging. Eventually, the heart begins to decompensate and the patient will develop symptoms consistent with aortic stenosis.

Advanced AS patients may develop congestive heart failure and cardiac arrhythmias (atrial fibrillation).