Not an expert, but I suspect for many there are warning signs that someone may die in their sleep (or exercising, or ???) long before the heart finally quits. This seems like a great way to monitor for that.
I’m an EMT, so not the deepest level of knowledge, but certain progressive things that will kill you (such as sepsis) would show noticeable trending in basic vitals like heart rate and respiratory rate. And sepsis is also common in geriatrics (catheter / surgery / G tube -> infection -> sepsis)
