Medically reviewed by Susan Kerrigan, MD and Marianne Madsen

Thanks to the growing interest in all things tech, many consumers are putting away their grandfather’s wristwatch in favor of a smartwatch which acts like a smartphone attached to their wrist. In addition to the utility of not having to carry a phone to look at emails to texts, the price point for many smartwatches has dropped into the affordable range (anywhere from $200-500 for the midrange models) which has increased the number of people wearing smartwatches on a daily basis. One interesting feature some smartwatches offer is the ability to track and record a person’s pulse rate, and scientists are examining the feasibility of using these devices to help cardiac patients self-monitor their heart. The Apple Watch has been the focus of some of these studies, first to determine its accuracy in reporting the heart rate and then to see if it could detect heart rate irregularities.

Apple Watch Accuracy in Measuring Heart Rate

A 2019 study in Belgium studied the accuracy of the Apple Watch in measuring the heart rate and energy expenditure of 40 cardiac patients (32 males, 8 females; average age 62) to determine if this technology could be used to support cardiac rehab exercise programs performed at home. Though previous studies have been done using other smartwatches, their results indicated that the heart rate measurement at high-intensity exercise levels was not always accurate. The results of the 2019 study with the Apple Watch showed promise. Researchers Falter et al. said that “Our results thus show good accuracy of HR measurements by the Apple Watch when compared to the gold standard ECG measurements when tested in patients with known heart disease.”

The Apple Watch Heart Study

Another 2019 study now underway is the Apple Watch Heart Study. This large-scale study is the first to look at whether an app (like that found on the Apple Watch) can detect atrial fibrillation (i.e., irregular heartbeat) which can be linked to a number of cardiac complications. One of its interesting features is that the entire study is handled virtually, with no in-person data collection, and this has made it possible to recruit such a large participant group in a relatively short time. With over 419,000 participants enrolled as of June 2019, this virtual study hopes to determine if push notifications about heartbeat irregularities from a smartphone-based app could be used to trigger clinical follow-up from a healthcare provider. This study, funded by Apple, Inc., in conjunction with the Stanford School of Medicine, hopes to target at least 75,000 participants over the age of 65 and 425,000 participants under the age of 65.

A study of this size does present challenges. While there could be some concerns about safety and privacy, no private health information was available to the study sponsor (Apple, Inc.). Other limitations to this study might include a bias toward younger users who are more comfortable with technology as well as the limitation of only detecting heart rate irregularities as a warning sign of a cardiac issue when that might not be a warning sign for everyone. Despite these limitations, researchers are hopeful that this large-scale study might provide a good foundation for future studies about using technology to prevent or reduce cardiac complications.

Whether you are a smartwatch wearer or not, knowing that you might be able to use technology to help you self-monitor your heart rate gives you another tool to promote health. Doctorpedia suggests talking to your physician about how you can use technology to move forward into greater health!

For more information about heart attacks, please visit HeartAttackpedia.

References

• Falter, M., Budts, W., Goetschalckx, K., Cornelissen, V., & Buys, R. (2019). Accuracy of Apple watch measurements for heart rate and energy expenditure in patients with cardiovascular disease: Cross-sectional study. JMIR mHealth and uHealth, 7(3), e11889. doi: 10.2196/11889
• Turakhia, M.P., Desai, M., Hedlin, H., Rajmane, A., Talati, N., Ferris, T., …& Perez, M.V. (2019). Rationale and design of a large-scale, app-based study to identify cardiac arrhythmias using a smartwatch: The Apple Heart Study. American Heart Journal, 207, 66-75. doi.org/10.1016/j.ahj.2018.09.002