The Full form of ECG is Electrocardiogram. ECG is a test that records the electrical activity of the heart. When the heart is beating, ECG records the electrical impulses. These impulses are recorded on a moving strip of paper or on a screen, i.e. it shows heart’s electrical activity as line tracings on paper. The spikes and dips are called waves that appear in the tracings. ECG is used to detect various heart-related problems, some are them are; abnormal heart rhythms, a heart attack in the past (myocardial infarction), enlargement of one side of the heart, cause of unexplained chest pain, thickness of the walls of the heart chambers, to check the performance of implants like pacemaker, to check the heart’s health if a person is suffering from diabetes, high cholesterol, high blood pressure, etc. There are three main types of ECG which are; Resting, Stress and Ambulatory. Resting ECG is carried out when the patient is lying down in a comfortable position; stress ECG is carried out when a person is using a treadmill or exercise bike and in ambulatory ECG, the patient is required to wear a small machine at his or her waist as it helps monitor the heart for one or more days.