What is it ?

An electrocardiogram (ECG or EKG) is a recording of the electrical activity of the heart. Each heartbeat is caused by an electrical impulse that causes the heart to squeeze. The ECG records the electrical pattern of the heartbeat. Many different diseases and conditions affect the ECG pattern. Small, sticky electrode patches are placed on chest, wrists, and ankles. These patches are connected to a machine that records the electrical activity of heart. The recording is printed on paper for doctor to interpret.