People frequently are surprised to find that they have, as the saying goes, leakage of the heart. It may be discovered on a life insurance examination or other routine examination, as for employment. They are surprised because they have had no symptoms from it, no intimations that any such condition existed.
Naturally, also, they are quite frightened, and it is not easy to re-assure them. And yet the fact is there are people who have leakage of the heart from the time of childhood to old age, and who live out their full expectancy and more, without ever hearing from the matter at all.
How can we explain this? Well, perhaps it can be made clear by a diagram and an appeal to the simple experience of mechanics.
The heart has four chambers, and the blood moves successively from one of these to the other, and then out either into the lungs or into the general body circulation. It is propelled by the contraction of the muscles which form the walls of these chambers. Obviously, for mechanical efficiency it is required that when the blood moves, it shall move in one direction and not backward. In order to prevent this, nature has placed valves between the chambers and at the mouths of the great blood vessels leading to the lungs and to the body circulation.
Now, sometimes through disease, these valves become shrunken so that they do not entirely cover the orifice. In that case some of the blood will go backwards through this opening in the valves. In doing so it causes a murmur which can be detected and which indicates the leakage.
While this, of course, destroys the perfect mechanism, nature can compensate surprisingly well for the difficulty. In the first place, the heart naturally has to do more work, because it has to push the same amount of blood through the lungs and into the body and add to this by pushing the blood that is lost through the leakage, and to compensate, it naturally enlarges. And here again we have an example of a condition which may frighten a person who does not understand it.
To be told that one has an enlarged heart would seem to indicate a grave condition when, as a matter of fact, it is simply a protective measure on the part, of nature.