Valve Pathology

All of the valve related issues have to do with a change in the capacityfor movement of the leaflets of the valve. The principle is that the leaflets of a valve undergo a pathological change to its composition (making it harder, thicker, etc) which in turn compromises its ability to perform its function as a valve. There are congenital conditions whichcan affect the cardiac valves, but they general present in childhood, soI’ve left them out.

Some of the key, relatively common conditions that came up were valve stenosis and insufficiency. Valve stenosis describes the abnormal narrowing of a blood vessel. The cusps of the valve become fused to form a dome with a smaller, central opening, thus throwing the pressure balance of the chambers out of that of the normal. As a result, it typically results in hypertrophy of the chamber concerned and leads the patient to demonstrate such symptoms as dyspnoea, angina and syncope on exertion.

Valve insufficiency is the inability of a cardiac valve to completely close during systole. As a result, the pressure gradient of the chambers of the heart propel blood in reverse, creating a regurgitation, or a backflow. This produces a characteristic murmur. This regurgitation can generate some chest pain and fatigue.

There are other conditions I found that might lead to similar failings of the heart valves and may be found in association to one of the conditions I’ve already mentioned. One such condition is Cardiac Fibrosis, which is an abnormal thickening of the valves due to high proliferation of cardiac fibroblasts. This thickening and hardening can lead to valvular dysfunction.

Endocarditis is the inflammation of the inner layer of the heart, the endocardium, and often involves the valves. It is characterised by a mass of platelets, fibrin, inflammatory cells and microorganisms. Since the valves of the heart do not receive any real blood supply, white blood cells have limited access to them, and if bacteria attach to them, there is decreased availability for immune response. Normally blood flows smoothly through the valves, but if they are in a damaged state, such as caused by rheumatic fever, then the likelihood of bacterial attachment is increased.

Another, perhaps more unlikely condition I found that might affect cardiac valve function was systemic lupus erythematosus. It’s a connective tissue, auto immune disease which (as the name implies) affects any part of the body. It involves the attacking of cells and tissue by the body’s immune system, resulting in inflammation. When affecting the heart, it can cause inflammation of any of the heart layers, such as endocarditis, as mentioned above.

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Sam