I want make sure about the fact in the documentation of MIT-BIH NSRDB here. They just say ECG 1 and ECG 2 but not what particularly.
I think they are the frontal plane channel and transverse plane channel but in which order, I do not know.
In their other database (MIT-BIH Arr.), #1 Channel was about MLII, but #2 Channel about V1. So I am confused.
Normally, I get data which says leads are this and this. Display channels can be this and this. Etc with this device, very clear manual.