Decoding ECG of the heart
Decoding ECG allows to reliably revealdeviations in cardiac activity, by examining the curve with the image of the heart rhythm. An electrocardiogram is a study of the activity of the heart activity for a certain period of time. It reflects electrical processes in the cardiac muscle, such as depolarization-excitation, and repolarization-the repair of myocardial cells. The electrocardiogram is produced transthoracally, that is, through the thorax, with the help of electrodes mounted on the skin surface with further recording of the readings for a special device. Correct interpretation 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 andintervals. Teeth of the cardiogram are the extreme points of the curve of the line, which are denoted by Latin letters characterizing the following indications: atrial contraction (P), ventricular contraction (Q, R, S) and ventricular relaxation (T). The "U" prong is impermanent and is rarely recorded. Segments are segments of a straight line connecting adjacent teeth. The most important is the decoding of the ECGin the P-Q and S-T segments. For example, isoline P-Q is formed during the excitation delay in the atrioventricular (atrioventricular) node. Intervals are a combination of teeth and segments. The most important intervals of the ECG are the P-Q and Q-T intervals.
Excitation in the myocardium of the cardiac ventriclescharacterized by the appearance on the ECG of a complex QRS complex, because it is not only more massive than the atrial muscle, but also has an interventricular septum. In the QRS complex, the sizes of the individual teeth.If the amplitude of the tooth exceeds 5 millimeters, itsis denoted by a large Latin letter Q, R, and S, when the amplitude of its movement is smaller, it is prescribed by the small letter q, r or s. Decoding ECG implies correct reading of the teeth. The tooth of R (r) is each upwards directed positive prong, which is part of the QRS complex. Any downward-directed negative tooth located before the tooth R is prescribed as Q (q), and located after the tooth R is the tooth S (s). The tooth Q characterizes the depolarization of the interventricular septum, with myocardial infarction it has an expanded and deeper meaning. The tooth R shows the depolarization of the main mass of the myocardium, and the tooth S displays the activity of the atrial divisions of the interventricular septum.
Decoding of the cardiac ECG consists of five points of study indications:
1. An analysis of the rhythm of the heart and cardiac conduction. This analysis implies an assessment of the heart rate, determination of the heart rate (HR), the establishment of an excitatory source and the conductivity characteristic;
2. Determination of the axis of electrical impulses of the heart;
3. Investigation of the atrial tooth P;
4. Study of the QRST complex;
5. Conclusion of ECG diagnostics.
Decoding of an electrocardiogram of a healthy heartof a person begins with a short atrial wave (a-b), reflecting the change in ventricular capacity when blood arrives at the moment of systole-atrial contraction. In the ECG, this wave is behind the P-wave and then goes upward, showing the systole of the ventricles. This steep ascent (b-d) follows the Q-wave and moves to the horizontal position(d-e). During the relaxation of the left ventricle and the decrease in pressure in it, the curve drops sharply downward (e-g), point g correlates with the opening of the mitral valve and the influx of blood into the ventricles. At the reduction wave, point c is located, which corresponds to the strained state of the mitral valve, and point f, corresponding to the closure of the aortic valve. Following the systolic wave, a ventricular filling wave (g-h) is formed and slowly filled (k-a). Then follows the repeat of the ECG cycle of a healthy human heart.