As a recent (2k) graduate, I had to study 12 lead ECGs.
Of course at the time deep learning wasn't exactly mainstream but there were discussions about using neural networks to sort and store ECG data more efficiently eg for ambulatory monitoring.
I did briefly explore whether a RAM chip could be used but at the time 16MB was far too expen$ive which would have been about the bare minimum. Also problematical was the loss of power so most commercial monitors recorded data to tape resembling answerphone storage.
Incidentally thanks to advances you can now approximate a 12 lead using three segmented electrodes with some degree of repeatability.
Even putting the amplifiers on individual electrodes as a very small chip scale (CSP) is a well known method now and if memory serves NASA pioneered this.