An electrocardiogram or EKG/ ECG is a test measuring the electrical activity of the heart. With each beat of the heart an electrical impulse, or “wave,” travels through the heart. The wave causes the heart muscles to squeeze and pump blood from the heart to the body.

An EKG/ECG shows how fast or slowly the heart is beating. It shows if the heart is beating regularly and where in the body the heartbeat is recorded. It also records how strong the heartbeat is and the timing of the electrical signal as it passes through the parts of the heart.