Valvular Heart Disease

    The valves keep the blood flowing in one direction, like one-way gates. They open when the pressure of the blood pushes them in the forward direction, and they close when the pressure on the other side of the valve pushes them back. Diseased valves may be too stiff to open easily or they may fail to close completely. Each of the four valves in and near the heart may be subject to obstruction if they are too stiff and to back leakage if they fail to close.

    A valve opening become narrowed and "tight", a condition that limits the blood flow through it and causes the blood and fluid behind it to back up as if behind a dam. The backup leads up to symptoms of congestive heart failure, heart chamber enlargement, and overgrowth of heart muscle, which can lead to angina. Various heart rhythm disorders can also develop.

    Valves may not close properly and therefore allow blood to leak back in the wrong direction. This causes the heart chambers to enlarge and pump blood inefficiently, because excess blood must be pumped forward to compensate for the amount that leaks back with each heartbeat. Again, this can lead to congestive heart failure, fatigue, and some rhythm disorders. A "leaky" valve does not mean that blood leaks out of the heart, but that blood leaks backward through the valve.

What are the causes? 

    Causes of valve disease range from congenital defects, to calcium deposits that accumulate on the valves as you age, to infections.

    It may take decades before damage to valves shows up. Oddly, you can have advanced valve disease before any symptoms develop, because your body compensates, leading to heart failure. 

    Therefore, if you develop valve disease, it is important that the problem be treated before it becomes so advanced that repair or replacement of the valve is no longer possible. The timing of procedures to repair or replace the damaged valve is important, because your doctor has to weigh the potential risks of surgery against the possibility that the problem will become too advanced to fix.

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©Copyright TQ Team 25896, 1999. The Circulatory System- Online Learning.