Electrocardiogram (EKG or ECG)

An electrocardiogram is a test that measures the electrical activity of the heartbeat. An electrical impulse, or “wave,” is created and moves through the heart with every beat. The heart muscle is squeezed by these waves pumping blood to the rest of the body. The timing of the top and lower chambers pumping is what is shown on a on an ECG.
The first wave called a “P wave” is made by the right and left atria or upper chambers. Next the wave called the “QRS complex” is represents the right and left ventricles (bottom chambers of the heart). The final “T wave” shows the ventricles recovering and returning to a rest state.