Practical Hydrotherapy Lesson 8—Heart Tonics
By GEO. THOMASON, M. D.
The normal rate at which the heart beats is about seventy-two times a minute while a person is engaged in the ordinary activities of life. There is a lessening of about six beats in the pulse rate when one is lying down or while sleeping. The heart accomplishes a prodigious amount of work every day. It toils on ceaselessly, constantly responding to the Creator’s commands to beat, sending the life-containing fluid to nourish every fiber and cell of the body. It is estimated that in carrying on its work the heart daily expends an amount of energy equivalent to the lifting of a body weighing twenty tons more than three feet from the ground. The only opportunity the heart has for rest is during the brief interval between the beats, or about four tenths of a second during the waking hours, and a little longer during sleep. There are many conditions which greatly increase the work of the heart, and modify or limit the period of rest. For example, during vigorous exercise it is necessary for the blood to pass more rapidly through the lungs to receive oxygen, and to the tissues to gather up the waste products thrown off, hence the heart beat is increased in frequency according as to the vigor of the exercise. The training of an athlete is largely a daily increase in the ability of the heart to cope with the extra strain brought upon it by violent exertion. “Good wind” means a strong heart. Getting “out of breath” is simply a failure of the heart to keep sufficient blood passing through the lungs to supply the increased amount of oxygen demanded by the tissues during vigorous exercise. The work of the heart is increased when the capillaries, or minute blood vessels in the skin and internal organs, are contracted. This is spoken of as increased resistance. In fevers the work of the heart is greatly increased in the effort to keep the blood vessels of the skin well filled, and thus more rapidly to eliminate heat, and also to carry the increased waste and poisonous substances to the excretory organs. The great increase in pulse rate during fever greatly lessens the period of rest between the beats of the heart, hence the danger of exhaustion. In pneumonia, in addition to the tendency to exhaustion from increased rate, there is an added danger in the fact that the consolidated area in the lung increases the work of the heart in forcing the blood through the lungs. Besides this, on account of diminished area in the lungs, the blood is less well oxygenated, and the heart itself is poorly nourished. Impoverishment of the blood—whether from lack of food, from living in close or poorly ventilated apartments, from sedentary habits, from lack of exercise, or from any other cause—produces a weakening of the heart. In the treatment of a weak heart it is essential to bear in mind that both the heart and the peripheral, or capillary, circulation are to be considered. As before mentioned, an increased or diminished peripheral resistance determines much as to the work of the heart, and it becomes doubly important when it is known that this state of the peripheral, or terminal, blood vessels, and hence the degree of resistance, may be so directly influenced and controlled. It is apparent, then, that by securing a free circulation of blood in the skin, the resistance will be overcome, and thus the work of the heart diminished. It is possible at the same time to make such applications as will lessen the rate of the heart beat, and thus prolong the period of rest between the beats. Cold applied over the heart slows the rate of the heart beat. The application may consist of a soft rubber bag partly filled with broken bits of ice, or of a linen towel or a cheese-cloth compress folded so as to be from six to eight inches square, and wrung from ice water. In most cases of heart weakness, the application over the heart may be continued from twenty to thirty minutes, and repeated two or three times a day. In case the cold compress is used, it must be renewed at least every three or four minutes. At the same time the blood vessels of the skin must be dilated by a very short hot bath of some sort, as an immersion bath at from 102° to 105°, four or five minutes, or a hot-blanket pack of eight or ten minutes’ duration, always to be followed by friction of the body with the hand or with a coarse cloth dipped frequently in cold water. A vigorous cold friction may be given without the preliminary hot bath, in many cases. It should be borne in mind that persons with weak hearts do not well tolerate either prolonged hot or general cold applications, but the careful and judicious treatment by the simple means suggested will afford relief from the unpleasant symptoms accompanying heart weakness.