People who get irregular pulse notifications on an Apple Watch but don’t have atrial fibrillation — the condition the feature focuses on detecting — could still have another type of problem with their heartbeat, according to a new study.
The findings show that even if someone with a concerning alert from their Apple Watch doesn’t get an atrial fibrillation diagnosis, they may not be in the clear, says study author Marco Perez, the director of the Inherited Arrhythmia Clinic at Stanford University Medical Center. “Even if you didn’t find atrial fibrillation, we were finding a lot of people who had something else that probably needed some clinical attention,” he says.
The analysis, published in the journal Circulation, was done using data from the Apple Heart Study, which was designed to test the Apple Watch’s ability to detect irregular heart rhythms. It launched in 2017 and included over 400,000 participants. In the study, anyone who got an irregular pulse notification from the watch was sent a clinical ECG patch, which could monitor their heart rhythm over a longer period of time. About 2,000 participants got an irregular pulse notification, and an earlier analysis showed that around a third of those people who then wore an ECG patch had atrial fibrillation show up during that monitoring period.