Decoding the ECG allows you to reliably identify abnormalities in cardiac activity by examining a curve depicting a heart rhythm. An electrocardiogram is a study of cardiac activity over a specific period of time. It reflects electrical processes in the heart muscle, such as depolarization - excitation, and repolarization - restoration of myocardial cells. An electrocardiogram is produced transthoracically, that is, through the chest, using electrodes mounted on the surface of the skin with further recording of the indications on a special device. The correct decoding of the ECG provides an opportunity to visually establish an accurate diagnosis and, if necessary, determine a timely course of treatment.
The ECG consists of images of teeth, segments and intervals. The teeth of the cardiogram are the extreme points of the curved line, which are indicated by Latin letters characterizing the following indications: atrial contraction (P), ventricular contraction (Q, R, S) and ventricular relaxation (T). The āUā tooth is intermittent and rarely registered. Segments are straight line segments connecting adjacent teeth. The most important is the decoding of the ECG in the PQ and ST segments. For example, the PQ isoline is formed during the period of delayed excitation in the atrioventricular (atrioventricular) node. Intervals are a combination of teeth and segments. The most important ECG intervals are the PQ and Q-T intervals.
Excitation in the myocardium of the heart ventricles is characterized by the appearance of a complex QRS complex on the ECG, since it is not only more massive than the atrial muscles, but also has an interventricular septum. In the QRS complex, the sizes of individual teeth are first evaluated . If the amplitude of the tooth exceeds 5 millimeters, it is denoted by a large Latin letter Q, R, and S, when the amplitude of its movement is smaller, it is prescribed with a small letter q, r or s. Deciphering the ECG implies the correct reading of the teeth. The R (r) tooth is each upward - positive tooth that is part of the QRS complex. Any downward-pointing negative tooth located in front of the R wave is registered as Q (q), and located after the R wave is the S wave (s). The Q wave characterizes the depolarization of the interventricular septum, with myocardial infarction it has an expanded and in-depth value. The tooth R shows the depolarization of the bulk of the myocardium, and the tooth S shows the activity of the atrial interventricular septum.
Decryption of the
ECG of the heart consists of five points of examination of indications:
1. Analysis of heart rhythm and cardiac conduction. This analysis involves evaluating heart rate, determining heart rate (HR), establishing an exciting source, and characterizing conductivity;
2. Determination of the axis of the electrical impulses of the heart;
3. The study of the atrial P wave;
4. The study of the QRST complex;
5. Conclusion of ECG diagnosis.
The decoding of the electrocardiogram of a healthy human heart begins with a short atrial wave (ab), which reflects the change in ventricular capacity when blood enters at the time of systole - atrial contraction. In the ECG, this wave is located behind the P wave and then goes upward, showing ventricular systole. This steep climb (b ā d) follows the Q wave and goes horizontal (d ā e). During the period of relaxation of the left ventricle and a decrease in pressure in it, the curve drops sharply down (e ā g), the point g corresponds to the opening of the mitral valve and a rush of blood into the ventricles. On the contraction wave is located point c, which corresponds to the tension state of the mitral valve, and point f, corresponding to the closure of the aortic valve. Following the systolic wave, a wave forms of filling the ventricles (g ā h) and slowly filling them (k ā a). The following is a repeat of the ECG cycle of a healthy human heart.