ECG Generation and Clinical Apply

Before heart contraction, heart generates electrical activity, the activity of atria and ventricular is transported to skin by human tissue. Electrocardiogram (ECG) is the chart of heart electrical activity per beat, which is recorded by Electrocardiograph device on the skin.

The Most importance of ECG is that it can help to diagnose arrhythmia. Today, ECG is becoming golden standard of clinical diagnosis to arrhythmia. Examine the heart working both by ECG and particular heart stimulation, which helps to estimate the generating mechanism and chose appropriate therapy.

Elements of the typical ECG in normal

On ECG recording paper, a horizontal axes represents time and vertical axes represents voltage;

The rate of paper (i.e. of recording of the ECG) is 25 mm/s which results in:           

>  1 mm = 0.04 sec (or each individual block)     

>  5 mm = 0.2 sec (or between 2 dark vertical lines)
 

The voltage recorded from the leads is also standardized on the paper where 1 mm = 0.1 mV (or between each individual block vertically) which results in:

>  5 mm = 0.5 mV (or between 2 dark horizontal lines)     

>  10 mm = 1.0 mV (this is how it is usually marked on the ECG)