When the body moves it produces electrical impulses, which the ECG is used to record the electrical impulses of the heart muscle. The heart muscle is made up of four chambers the upper atria’s and the lower ventricles, these electrical systems causes the heart to contract and as the heart contracts it produces a tiny electrical currents. An ECG tracing of the cardiac cycle (heart beat) consist of a p wave, a QRS complex, and a t wave. A line called the isoelectric line (baseline) shows up as a flat line that separates the different waves and signify the periods in the cardiac cycle when there are no currents present.
