Electrocardiography in Small Animals
by Wendy Blount
An electrocardiogram (ECG) is a test that records the electrical activity of the heart as a graphic display on graph paper, known as a trace. The electrical impulses are recorded as waves or deflections and one heartbeat is usually recorded as a grouping of waves known as the P-QRS-T complex. Clip-on electrodes attached to the limbs and various points on the thorax pick up the electrical impulses produced by a beating heart, which can be detected in the heart itself and in the body surrounding it.