If you google anything today you'll see an image of Willem Einthoven. He created the first electrocardiogram (ECG) in 1895. If he was still alive he would be celbrating his 159th birthday today. Willam received the Nobel Prize in Medicine in 1924 for his invention.
If you're interested you can read about him and his invention here:
en.wikipedia.org/wiki/Wille...
ECGs have certainly come a long way (I bet he'd be impressed by how tiny and portable ECGs are now). I for one am grateful for the amazing medical and scientific minds that have given us the technology and treatments we have today. With continued research, hopefully one day AF (and many other illnesses) will be no more.