ECG: the norm of basic indicators

Electrocardiography is an important non-invasive method for diagnosing the functional activity of the heart. It is based on the registration of electrical potentials with a contraction of the myocardium, which are displayed on the display or paper.

This examination is indicated for hypertension, chest pain and dyspnea, after the age of 40, when smoking and high cholesterol in the body, before any operation, during pregnancy and after the infection.

For the ECG, a special device is used - an electrocardiograph with matching electrodes.

The ECG is normally characterized by the following elements:

1. Teeth, which are denoted by the letters P, Q, R, and also S, T, U.

It should be noted that the tooth P shows how the excitation of the atria passes. Normally, its duration is 0.06-0.1 s, the amplitude is 0.05-2.5 mm.

With the ECG, the norm of the indices is determined taking into account the fact that the width of the smallest square on paper where the electrical potentials of the heart are recorded is 0.04 seconds, and the height corresponds to a voltage of 0.1 millivolts.

ECG norm for other teeth:

• Q tooth should be with a duration of <0.03 s and a voltage - <¼ of the amplitude of the tooth R;

• R tooth should be 0.03-0.04 s and up to 20 mm (in V5 and V6 can increase to 26);

• S - normally the duration of this tooth reaches 0.03 s, the voltage - <8 in the lead I II, in V1 it can be <25;

• ECG: the tooth norm is T-0.16 s, and the amplitude is <1/2 from the R wave;

• U - the norm is 0,06-16 s, the height of this denticle should be about 2-3 mm.

2. Intervals: PQ (corresponds to the passage of the pulse between the atrium and ventricle), QT, and also RR, ST. The last interval, together with the T wave, characterizes repolarization, which passes in the ventricles of the heart;

3. Estimate also the complex QRST, indicating the electric systole of the ventricles.

To register electrical impulses in the myocardium apply three standard, as well as three reinforced and six thoracic ECG leads. The rate of the results depends on the distance in which the duration and amplitude of the teeth are determined.

It is worth noting that the ECG is an extremely valuable diagnostic technique. With ECG, the norm of all elements indicates the regularity and correct frequency of heart contractions , as well as the normal work of the pacemaker. With certain changes, it is possible to judge the presence of arrhythmias, conduction disorders of the heart or about possible violations of the blood supply to the myocardium and its ischemia.

PR and ECG the amplitude norm is important for proper diagnosis, as when it increases you can talk about the hypertrophy of the corresponding areas of the heart that develops in hypertension and certain heart diseases.

It is necessary to say that ECG is an accessible and informative diagnostic method, but its main drawback is the short-term registration of electrical impulses that spread by the heart muscle. This does not allow us to detect periodic disturbances in the work of the heart. To register such pathologies, monitoring electrocardiography is used, which is conducted for 48 hours and gives a more complete picture of the functioning of the myocardium.

In addition, for carrying out differential diagnostics of organic and functional disorders in the heart, ECG with orthostatic loading or hyperventilation, as well as against the introduction of separate drugs (medicinal tests) can be performed.