An electrocardiogram is a graphic record of changes in electrical voltage when the heart beats. The machine by which the electrocardiogram is recorded is known as electrocardiograph.
The importance of ECG is that it gives us accurate information about the working of heart. So, it is very important in diagnosis of a number of heart diseases.

Test Your Understanding and Answer These Questions:
- Expand ECG.
- What is ECG? What is its importance?