Is an Apple Watch, by itself, enough to provide you with adequate warning that you’re experiencing heart issues such as atrial fibrillation (AFib)? According to the results of a new study, probably not. 

“Wearables allow patients to capture more real-time heart health data than ever before, but this study shows medical-grade technology is still necessary to provide doctors with an accurate and reliable way to detect and manage cardiac conditions like AFib,” said Alan Cheng, M.D., chief medical officer of the Cardiac Rhythm Management business, which is part of the Cardiovascular Portfolio at Medtronic.  

AFib is an irregular and potentially dangerous heart rhythm that’s becoming increasingly common in the United States. It’s a serious, chronic, and progressive heart disease, and it’s estimated that by 2030, more than 12 million Americans will have Afib¹. Wearable devices such as smartwatches that can detect AFib have become increasingly popular. 

But the first-of-its-kind, app-based DEFINE AFib clinical study of nearly 1,000 people found that a small medical-grade Medtronic heart monitor implanted under the skin detected far more episodes of AFib than the wearable did. In the study, 40% of AFib episodes happened while the Apple Watch wasn’t being worn²; AFib episodes can happen at night whene wearables are often removed to recharge. The ICM, on the other hand, monitors heart activity 24 hours a day, seven days a week, for years at a time.  

In addition, the study found that when the Apple Watch was being worn, its irregular rhythm notification feature detected only 26% of the AFib episodes found by the ICMs.  

Does this mean you should ditch your wearable? 

Absolutely not. 

If a wearable detects an AFib episode, the individual wearing it likely had an AFib event, noted Jonathan P. Piccini, M.D., clinical cardiac electrophysiologist and professor of medicine and population health at Duke University Hospital and the Duke Clinical Research Institute, and chair of the DEFINE AFib clinical study steering committee.  

But the watch may not catch every episode.  

“For doctors, the primary take-home bedside message is that consumer wearables can have limitations. So it’s really important to validate that with continuous monitoring technology to make sure we have the right answer,” said Dr. Piccini. 

“Smart watches are a great tool to give you a sense of your overall health status,” added Dr. Cheng. “Medical-grade devices with continuous monitoring capabilities are more appropriate for screening for and especially helping manage chronic conditions like AFib.” 

* © 2025 Medtronic. Medtronic, Medtronic logo and Engineering the Extraordinary are trademarks of Medtronic.  

™* Third-party brands are trademarks of their respective owners. All other brands are trademarks of a Medtronic company.   

Important safety information about the LINQ family of ICMs: 

https://www.medtronic.com/en-us/l/patients/treatments-therapies/insertable-heart-monitors/getting-monitor/important-safety-information.html 

L001-01292025

---

Related content