Basic Electrocardiography, depolarization is the electrical activation of the myocardium (the muscular tissue of the hear):
- P wave: ECG deflection representing atrial depolarization. Atrial re-polarization occurs during ventricular depolarization and is obscured.
- QRS wave: ECG deflection representing ventricular depolarization.
- T wave: ECG defection representing ventricular re-polarization.
Just for fun, some “hearts” and crafts: