Characteristics of normal electrocardiogram

The characteristic of normal electrocardiogram is that P wave represents the potential change of atrial depolarization, and its shape is obtuse. It rises in leads ⅰ, ⅱ, aVF, ⅴ4 ~ⅴ6, and falls in lead aVR, and the time is less than 0. 12 seconds.

The amplitude of limb lead is less than 0.25mv, the amplitude of chest lead is less than 0.2mv, the heart rate of normal adults is 60- 100 beats/min, and the PR interval is 0.12-0.20s. It varies with age and heart rate. The younger the age, the faster the heart rate and the shorter the PR interval, which is less than 0.22 seconds for the elderly.

Extended data:

Different wires are formed between the two electrodes or between the electrodes and the central potential terminal, which are connected with the positive and negative electrodes of the galvanometer of the electrocardiograph to record the electrical activity of the heart.

A bipolar wire is formed between two electrodes, one of which is a positive electrode and the other is a negative electrode. Bipolar limb leads include lead I, lead II and lead III. A monopole wire is formed between the electrode and the center potential terminal. At this time, the detection electrode is positive and the central potential terminal is negative.

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