How an ECG is performed and how to prepare for the patient
Electrocardiography is a technique for recording and studying the electric fields generated by the heart. Electrocardiography is a relatively inexpensive but valuable method of electrophysiological instrumental diagnostics in cardiology. A direct result of electrocardiography is an electrocardiogram (ECG).
Electrocardiography underlies many diagnostic studies - Holter monitoring, bicycle ergometry, transesophageal ECG recording, ECG using drugs, remote ECG, monitor monitoring in intensive care units or during operations. The cardiogram is a recording of the electrical activity of the heart, which is produced from the surface of the patient's body - from the upper and lower extremities and chest. For ECG recording (depending on the type of apparatus), electrodes, special suction cups and cuffs are used. ECG removal takes 5-10 minutes. ECG is recorded at different speeds. Usually the speed of the paper is 25 mm / sec. At the same time, 1 mm curve is 0.04 seconds. Sometimes for a more detailed recording using the speed of 50 and even 100 mm / sec. With prolonged ECG recording to save paper, use a lower speed - from 2.5 to 10 mm / sec.
In the new series of articles, we will tell you about the specifics of the ECG procedure, as well as how to properly prepare for it and be able to independently decipher the results obtained by comparing our own indicators with the norm.
Electrocardiography (ECG) is a non-invasive test, which provides valuable information about the condition of the heart. The essence of this method consists in the registration of electrical potentials that occur during the work of the heart and in their graphic display on the display or paper.
A bit of history. Interest in the electrical activity of the heart arose in the XIX century. German scientists R. Kellyker and I. Müller in 1856 discovered electrical phenomena in the contracting heart muscle. The English physiologist R. Waller in 1873 produced the first recording of the electrical activity of a human heart. At the beginning of the twentieth century, the Dutch physiologist Willem Einthoven introduced the ECG into clinical practice. It is fair to say that Einthoven recorded only three standard leads - I, II and III (“Einthoven's triangle”). Three more leads (reinforced leads from the extremities - aVR, aVL, aVF) were proposed in the 1920s by Goldberger. A little later, Wilson suggested recording chest leads (V1-V6). This is how the current classical ECG of 12 leads was formed. In order to understand what kind of revolution electrocardiography made in medicine, it suffices to say that in 1924 the progenitor of the ECG Willem Einthoven won the Nobel Prize.
ECG how to prepare
Contrary to the opinion of cardiologists, it is considered that the ECG does not require special preparation. The study of the work of the heart muscle involves the avoidance of stress, fatigue, and requires complete rest. On the day of the procedure, you need to sleep well and ignore the morning exercises. If the procedure is scheduled for the morning time, then you should avoid a hearty breakfast, but it is better to completely abandon it. With the upcoming day procedure, you should limit yourself to a light snack 2 hours before the session.
Do not forget to reduce the amount of fluid intake that affects muscle function. Avoid coffee, tea and other energy drinks. They will contribute to the stimulation of cardiac activity, and the results will be distorted.
It is advisable to take a shower. The body does not need to be applied care products, because the components of creams and lotions, will contribute to the formation of a greasy film on the surface, which will adversely affect the contact of the electrodes with the skin.
Just before the ECG, try to relax as much as possible. Sit with your eyes closed, restore breathing - this will ensure an even pulse and objective readings of the device.
Is ECG Harmful?
The logical question of whether an ECG is harmful can be answered based on the advantages of this diagnostic method:
- accuracy of information
- session safety and comfort
- efficiency (10 min)
- no health or pregnancy restrictions
As you have already understood, it is impossible to damage the ECG health, since this method is based on the removal of the heart rate indices and does not produce any radiation or effects on the body. Moreover, people whose work is associated with constant physical exertion, electrocardiography is done almost daily, which once again confirms its absolute harmlessness.
How is an ECG done if the time is right?
You will be prompted to remove outer clothing, so that nothing will prevent access to the chest, and release the lower leg. Places where electrodes will be attached will be treated with alcohol, which will cause a special gel.
The next step is to fix the cuffs and suction cups. They are fixed on the hands, in the ankles and chest. Ten electrodes will track the rhythm of the heart, and will give an encrypted result.
The heart plays the role of an electrical generator. The tissues of the body have a high degree of electrical conductivity, which allows to observe the electrical impulses of the heart by applying electrodes to parts of the body. The readings of the biopotentials are processed by the electrocardiograph, and outputs data in the form of a summary picture - the propagation of excitation signals through the muscle in a graphic image. More specifically, the difference in electrical voltage.
The impulse propagation through the heart sections contributes to the depolarization of myocardial cells, during which some cells acquire a positive charge, the other part - a negative one. So there is a potential difference. In the case of complete depolarization (contraction) or repolarization (relaxation) of the cell, the voltage difference was not observed. The device records the EMF - the electromotive force of the heart.
After an ECG is performed, the doctor gets an idea of the body's work and the existing abnormalities.
An electrocardiogram is able to reveal:
- myocardial infarction
ECG how often do
As we have already found out, this method is absolutely harmless to the body. So you can forget about the risk of getting any complications from frequent monitoring of the heart muscle. On the contrary, the portal “All about hypertension” recommends electrocardiography when the first alarming symptoms and discomfort occur.
The reason for the ECG are:
- chest discomfort
- shortness of breath
- excess weight
- chronic stress
- rapid rhythm
- suspected hypertension
Of course, you should not be checked daily - it is simply meaningless. However, the decision on the ECG frequency should be made by the attending physician, based on the history.
Doctors recommend that people over the age of 40 annually examine the heart, and representatives of more mature age - every 1 quarter.
The received cardiogram will be interpreted, and if necessary, treatment is prescribed. Remember that the disease is better to warn in advance.
In the following articles, we will look at the example of a finished cardiogram for ways of its decoding and compliance with the norms.