DEFECTS IN THE HEART VALVES

In most of the countries today, the heart patients have outnumbered any other disease like cancer etc. out of every 100 of these heart patients only one or two do not have blockages in the heart arteries. They probably suffer from disorder called heart valve defects (Valvular Heart Disease) or infection in the heart called “infective endocarditis” or “pericarditis”. In this issue of Heart talk we are going to cover the “Defects in the Heart Valves”.

Heart is one of the finest and the most sophisticated pump of the world and no amount of technological and engineering development can duplicate this splendid piece of work.

For a moment consider the job of the heart. It has to receive impure blood from all over the body; propel it then to the lungs for purification; receive the purified blood from the lungs and again push it forward to the entire body that needs it for its various activities. It has four chambers; all arranged in a series with the lungs present between chambers 2 and 3. The blood moves in one chamber 3 to 4 and finally from chamber 4 to the “Aorta” the inch diameter tube which takes the blood from the heart for distribution to the whole body. For this unidirectional flow four valves are fitted in the heart and they are called Tricuspid valve, pulmonary valve, mitral valve and Aortic valve.

These valves are like gates, which open in one direction only. They are fully open when blood flows in that direction. But they get completely shut down after the blood has passed through. This prevents backflow. Thus the blood keeps on moving forward in one direction. Valvular defects can be two types. One when the valves cannot open completely thus obstructing the flow and the other where they cannot completely close allowing the blood to leak in the backward direction. The first condition is called “Stenosis” of the valve and the second one is called “Regurgitation” (leaking) of the valve. Both create problems for the blood flow through the heart and thus lead to less oxygen availability in the body. In both cases it leads to breathlessness.

These valve defects are due to various reasons. It could be due to wrong manufacturing of the valve at birth (called the congenital heart disease), damage to the valve doors (cusps) due to a disease called Rheumatic heart disease or due to over stretching of the rims/boundaries of the door causing leaking valves (mostly following enlargement of the heart after heart attacks).

Valvular heart disease is the name given to any dysfunction or abnormality of one or more of the heart’s four valves, including the mitral valve and aortic valve on the left side, and the tricuspid valve and pulmonic valve on the right side. In a normally functioning heart, the four valves (flaps made of tissue) keep blood flowing in one direction and one at the right time. They act as gates that swing open to allow blood to flow through and then tightly shut until the next cycle begins. There are a number of different types of valvular heart disease, including:

1.       Valvular Stenosis: A condition in which there is a narrowing, stiffening thickening, fusion or blockage of one or more valves of the heart. As a result, the defective valve can interfere with the smooth passage of blood that should be flowing through it. Depending on which valve is affected, the diagnosis may be aortic stenosis, mitral stenosis, pulmonic stenosis or tricuspid stenosis.

2.       Valvular regurgitation: A condition in which blood leaks back in the wrong direction because one or more of the heart’s valves is closing improperly. The nature and severity of the leakage, in turn, may keep the heart from circulating an adequate amount of blood through the defective valve. Depending on which valve is affected, the diagnosis may be aortic regurgitation, mitral regurgitation, pulmonary regurgitation or tricuspid regurgitation.

3.       Atresia of one of the valve: A serious condition in which one of the valves has failed to develop properly and is completely closed at birth. Depending on which valve is affected, the diagnosis may be aortic atresia, mitral atresia, pulmonary atresia or tricuspid atresia.

4.       Mitral valve prolaps: A common and rarely serious condition in which the two flaps of the mitral valve (located between the left atrium and the left ventricle) cannot close properly, and may result in blood leaking back into the left atrium. It is due to either one (or both) of the flaps being too large, or because the muscle “hinges” of the flaps are too long.   

 

Hope you liked this article!

This article is written by Dr. Bimal Chhajer (India’s No. 1 heart doctor)