ECG is the electrical activity of the heart recorded in each heart beat. the electricity produced in teh heart is recorded by the surface electrodes placed on teh body at varios sites. it looks at theheart from various angles and hence is a very useful and informative test in the diagnosis of the heart disease. It is an inexpensive and a non-invasive test and can be repeated as many times. It is of great help in managin a patient who has presented with the chest pain.The test is an initial test in any acute chest pain and does not need any supportive test if it catches the evidence suggestive of Coronary artery blockage giving rise to the Heart Attack.Nornally it is recorded in the graph paper with athermal printer, where we have about 40 seconds of recording. We can see multiple waves and segment , which the doctor analyses.It gives us the HEart rate, gives us information about any abnormal rhythm disturbance, chamber enlargment,elecrolyte imbalance,coronary artery disease and many other informations.please keep your previous ecg always for records to compare it with teh present one. we can have much more information on this simple test later on.