An EKG (electrocardiogram) is a test that measures the electrical activity of the heart. The test is conducted to assess the heart’s rhythm and activity and to detect certain heart conditions. The test is conducted by placing electrodes on the chest, arms, and legs, which transmit the electrical signals of the heart to a machine. The machine then records a graph that reflects the electrical activity of the heart. The graph is analyzed to assess the heart’s rhythm and activity.