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).

I believe an error has been made in the description of the first electrocardiogram of Case 29–1965 of the Case Records of the Massachusetts General Hospital. Dr ...