The different leads of the ECG examine cardiac electrical activity from different perspectives. In this video we teach you the perspectives of the 12 ECG leads on cardiac depolarosiation and repolarisation. We consider the 12 leads in two groups of six, with the six chest leads (V1-V6, also referred to as the precordial leads) examining the flow of cardiac depolarisation and repolarisation in the horizontal plan and a second group of six leads (the standard leads and augmented leads) which examine these events in the vertical plane. For the experienced practitioner, looking at different areas on the ECG readout is like looking at different anatomical regions of the heart. Also, understanding the lead perspectives is crucial in the interpretation of cardiac arrhythmias.