adam kuperstein from our nbc station here in new york has story. >> reporter: jessica malone had justrlem to hell's kitchen when her apple phone started vibrating. >> it turned red and was vibrating and said seek medical attention i was really thrown off, okay, this is serious. >> reporter: jessica docked her bike and rushed to the african american. >> she had come in with severe palpitation and chest pain and light-headedness and dizziness. >> reporter: dr. mohammed was on call at mount sinai west. he had an abnormal heart palpitation call afib. >> this is really serious. your family needs to come down here. >> reporter: concerned about blood clots and a potential stroke, doctors had to use electrical currents to shock jessica's heart into a normal rhythm. it worked and the next day she was able to go home. >> the apple watches are very helpful because they provide patients with a very quick alert system for them to see a health care provider. >> reporter: if not for the alert center watch, jessica says she would have gone home and taken a nap. instead, she credits the apple watch fo