It is a reference to the number of electrodes attached to the monitor. A 12 lead setup can provide a much more detailed signal and thus be used in different dia

It is a reference to the number of electrodes attached to the monitor. A 12 lead setup can provide a much more detailed signal and thus be used in different diagnostics than a lower lead obtained trace. https://www.ncbi.nlm.nih.gov/books/NBK538203/ https://www.ncbi.nlm.nih.gov/books/NBK538203/