Материал: Презентация экг инглиш

Generation of ECG waves and intervals:

P – depolarization of atriums,

QRS - depolarization of ventricles, ST,Т,U - repolarization of ventricles. The

QRS-T cycle corresponds to different phases of the ventricular action potential.

Длительность.

The duration of the waves, complexes and intervals

is the distance in mm multiplied by the division value (at a speed of 50 mm / s, 1 mm corresponds to 0.02 sec; 25mm / s - 0.04 sec.).

Высота.

The height of the waves (P, R, T) and depth (Q and S) are measured in millimeters and millivolts based on

I mv = 10 mm.

Other characteristics.

1)P ≤0.10 ≤2-2.5 (+) I, II, aVF, (-) aVR

may be (±) III, aVL, V1-2 2)PQ 0.12—0.20 - isoline

3)QRS 0.06—0.10 ≥5 all leads; 4)Q(<0.04 s, ≤2 mm) except aVR,V1-2 ;

transition zone (R wave = S wave) between V2 –V4

5)ST - - isoline (as rule); may be - (+)1 or

(-) 0.5 mm in aVL, aVF. aVR; 6)QT - 0.30—0.46

Interpretation of ECG

In the beginning of interpretation of ECG technical conditions of tape

recording must be defined (voltage of the ECG and speed of a tape).

The ECG graph paper records the time (interval) between cardiac electrical events along the horizontal axis and their amplitude (voltage) along the vertical axis.

It is important for correct estimation of heart rate, amplitude

and duration of ECG waves and intervals.