Apple Inc. joined the healthcare industry today with the launch the new Apple Health Study app for the Apple Watch, which gathers heart rate data for a medical study conducted by Stanford University.

First announced at Apple’s big press event in September, the new app passively monitors users’ heart rhythms and heart rates for signs of atrial fibrillation or AFib. That’s an irregular heart rhythm that Apple says is the leading cause of stroke and is responsible for 130,000 deaths and 750,000 hospitalizations in the U.S. every year.

According to Apple, millions of people suffer from AFib, but many are unaware of the condition until it causes serious problems. The company hopes to address this problem through the Apple Health Study app, which can alert users if it spots signs of AFib in their heart data and also share that information with medical researchers working to understand AFib better.

Users alerted by the app will get a free video consultation with one of the health professionals working on the study, who will provide the user with further analysis of their irregular heart rate. The consultation can then connect users with a board-certified, licensed primary care provider from American Well.

“Every week we receive incredible customer letters about how Apple Watch has affected their lives, including learning that they have AFib. These stories inspire us and we’re determined to do more to help people understand their health,” said Jeff Williams, Apple’s chief operations officer. “Working alongside the medical community, not only can we inform people of certain health conditions, we also hope to advance discoveries in heart science.”

Added Lloyd Minor, dean of Stanford University School of Medicine, “Through the Apple Heart Study, Stanford Medicine faculty will explore how technology like Apple Watch’s heart rate sensor can help usher in a new era of proactive health care central to our Precision Health approach.”

Apple Health Study is an opt-in app that is separate from Apple Watch’s built-in monitoring tools, so users who do not want their heart data shared with the study can simply choose not to download the app. Apple also said that while the heart sensor data will be collected for research analysis, Apple itself will not have access to any personally identifiable information.

Photo: Apple