Hey, I've several questions conerning the ECG if someone has time to help out. 1) My teacher said that in the ventricles: last depolarization, first repolarization. He mentioned that it was due to the plateu of action potential happening earlier. How is that? 2) How come T and P-waves can either be negative or positive? Shouldn't If you know any good websites explaining ECG, it would be great to post them too. I appreciate your input.