Apple Is Developing an EKG Heart Monitor for Its Smartwatch

Apple Inc. is developing an advanced heart-monitoring feature for future versions of its smartwatch, part of a broader push by the company to turn what was once a luxury fashion accessory into a serious medical device, according to people familiar with the plan.

A version being tested requires users to squeeze the frame of the Apple Watch with two fingers from the hand that’s not wearing the device, one of the people said. It then passes an imperceptible current across the person’s chest to track electrical signals in the heart and detect any abnormalities like irregular heart rates. Such conditions can increase the risk of strokes and heart failure and develop in about one-quarter of people over 40, according to the U.S. Centers for Disease Control and Prevention.