When you start learning about ECG, it is important to learn the basics first. Be sure to understand what depolarization and repolarization are, and how the depolarization wave is seen on ECG. Alright, so electrocardiogram, or ECG is based on electrodes that detect charges outside of the cell. At rest, cells are negatively charged compared to the slightly positive outside environment. When they depolarize, they become positively charged, while their environment becomes negatively charged. Now, in