The pulse is an oscillatory movement of the walls of arteries of a jerky nature. These fluctuations occur as a result of changes in blood pressure in them during heart contractions. The nature (rhythm, tension, filling, frequency) of the pulse depends on the cardiac activity and the condition of the arteries. A change in the nature of fluctuations can be due to mental stress, work, changes in ambient temperature, the introduction of certain substances (drugs, alcohol, and others) into the body.
Heart rate is measured using various methods. The easiest is feeling. It is carried out, as a rule, at the base of the first (thumb) finger on the palmar surface of the left forearm. Feel the radial artery. In order for the pulse rate to be felt most clearly, the hand should be in a relaxed state, lie free of tension, freely.
It should be said that the oscillations are felt on other arteries (for example, the ulnar, femoral, temporal and others). The normal heart rate is from seventy to eighty beats per minute.
Counting the number of oscillations is carried out within fifteen or thirty seconds. The resulting amount is multiplied by two or four, respectively. So, it turns out the heart rate per minute. If there are significant changes in the number of fluctuations, then the calculation is carried out within one minute, in order to avoid errors. In the medical history, a record is made daily or a pulse curve is drawn on the temperature sheet similar to the temperature curve.
The number of fluctuations in physiological conditions is set under the influence of many factors.
So, heart rate depends on age. As practice shows, with age, the number of fluctuations decreases. The highest heart rate in children in the first years of life.
The number of strokes depends on the nature of muscle work. Against the background of physical exertion, the pulse accelerates. The increase occurs against the background of emotional stress.
A change in the number of vibrations occurs also depending on the time of day. So, at night during sleep, the heart rate decreases.
The number of strokes is directly related to the floor. It was found that women have a heart rate of five to ten beats more than men.
The nature of the oscillations is greatly influenced by various substances. For example, adrenaline, atropine, caffeine, alcohol increase the frequency, but digitalis, on the contrary, slows down.
The number of oscillations greater than ninety beats per minute is called tachycardia. Acceleration of the pulse is characteristic of physical exertion, emotional stress, changes in body position. Prolonged tachycardia may be due to fever. Against the background of fever, an increase in temperature by one degree leads to an increase in heart rate by 8-10 beats / min. The patient’s condition is worse, the stronger the oscillation frequency exceeds the temperature indicator. Of particular danger is the state when the number of strokes increases with a drop in body temperature.