Boston March 22, 2018 5:56 pm New Accessory for Apple Watch Could Save Lives The tiny EKG measures for an irregular heart beat, which is a major risk factor for stroke and heart failure. NBC10 Boston health reporter Kristy Lee explains how it works. US & World Videos 3:45 What is brain fog? 3:30 Mass. assisting in nationwide IVF access 2:58 Climate change is causing distress, anxiety among young Americans 2:44 Medical professionals use AI to help determine cancer treatment 1:56 Voters feeling stress as Election Day approaches