Remote pacemaker monitors

This morning I visited Mrs D in Windsor. She's been telling me about this device with a green light that she has in her room. This is her pacemaker monitor and is connected directly to the hospital. She was actually shown the room where this is placed at the hospital, and was told that, if anything should go wrong, an ambulance would be immediately dispatched for her. And, as so very often happens, I had to look it up on the Internet, to find out what Mrs D is talk about and how this works. We are so lucky to have this sort of medical care!