In a “normal” electrocardiogram (ECG), the transition of the QRS axis in the precordial leads occurs between leads V 3 and V 4 (i.e., there is a dominant S in V 3 and a dominant R in V 4).

If you’ve ever heard (or witnessed yourself!) that hurricanes spin clockwise in one part of the world and counterclockwise in another, you’re not imagining things. It’s a real phenomenon, and it all ...