My husband is in the hospital right now and will be getting a defibrillator implanted. The doctor told him that if it triggers because of tachycardia he will feel the jolt as it shocks him to a normal rhythm. He unfortunately got the paddles the other day and said it's a huge jolt. The doctor said he would have no warning if the implant needed to shock him and I worry that he would be driving or something. I have an Apple Watch and showed my husband how the heart rate function works. I think I'd like him to get the Apple Watch 2 but I wonder if there is an app than could alert him with a tap on the wrist if his pulse rate goes over about 170 or so. That way he can start actively monitoring his heart and may get warning before a jolt occurs.