Apple Watch 4: Do ECG Readings Give A-Fib Patients a False Sense of Security?

Added: 2019

To monitor for A-Fib yourself, the Apple Watch (Series 6, the gold standard of wearable monitors) can generate an ECG similar to a single-lead electrocardiogram. It’s very sophisticated and can monitor both for A-Fib and for many other health parameters. The series 6 has a blood oxygen sensor as well as a heart-rate check. Upon FDA approval, it will have real-time monitoring of blood pressure.

Added: August 6, 2020: Marilyn Shook writes “Love my Apple Watch 5! Great accurate ECG strip to share.” (Read Marilyn’s A-Fib story at https://a-fib.com/marilyn-shook-a-fib-story-86-post-pva-complication/.)

The main alternatives to the Apple Watch are the Samsung Galaxy Watch and wearables featuring Google’s Wear OS softwear. The market leader for Wear OS is Fossil (Generation 5)  Another Fossil product is the Diesel On Fadelite. The Suunto 7 from Finland has GPS.

We received a couple of emails about the new Apple Watch 4. As many A-Fib patients may be aware, recently Apple unveiled the next generation of Apple Watch which includes a second generation optical heart sensor.

Among several interesting features, it can generate an ECG tracing similar to that of a single-lead electrocardiograph.

In her Sept. 14, 2018 editorial on Medscape.com, ECG Readings From the Apple Watch? This Doctor Is Leery, Dr. Hansa Bhargava gives her perspective of this feature for those diagnosed with atrial fibrillation. She writes that she finds the Apple Watch’s ability to do a one-lead ECG interesting but has some reservations.

“…Here’s what I worry about: the false sense of security that a person could have.

Apple Watch 4 screens

Being able to do a one-lead ECG is definitely interesting, but does it always help? Here’s a scenario. A 40-year-old runner starts feeling dizzy, lightheaded, and has chest pain. He worries but remembers that there is an ECG function on his watch. He proceeds to do the ECG which then reads “normal.” Because of this he decides to continue to run.

What he doesn’t know is that this is only a one-lead ECG, and even though it seems normal, it is an isolated data point; more information is needed to diagnose what is going on. What if he is having angina? In fact, 30% of cardiovascular events happen to people under the age of 65. One lead on an ECG could certainly miss this; in fact, even a 12-lead ECG, if the only isolated data point, could miss this.

Dr. Andrew Moore, an emergency department physician at the Oregon Health and Science University is also skeptical of the Apple Watch 4 ECG feature:

“The ECG thing is a little bit overhyped in terms of what it will really provide. …The tech that Apple is working with is very rudimentary compared to what we’d do for someone in a hospital or health care setting.” 

While the watch can detect changes in the patterns of a person’s heart rate such as too fast, too slow, or beating irregularly—signifying A-Fib, the watch doesn’t diagnose a medical issue.

Apple Watch and Other DIY Heart Rate Monitors

Guide to HRMs and Handheld ECG monitors

Keep in mind these doctors’ concerns apply to all consumer heart rate monitors (HRM), those with optical heart sensors and those with electrode-containing monitors.

Wrist vs. Chest Bands: Wrist-band optical heart-rate monitors (like Apple Watch 4) may be more convenient or comfortable and have advanced over the years. But researchers found that electrode-containing chest-strap monitors were always more accurate than their wrist counterparts and more reliable and consistent. To learn about this research, read When Tracking Your Heart: Is a Wrist-Worn Heart Rate Monitor Just as Good as a Chest Strap Monitor?

Blue-tooth chest-band with smartphone app

As an A-Fib patient, when monitoring your heart beat rate is important to you (while exercising or doing heavy work), you’ll want to stick with an electrode-containing monitor (chest band-style, shirts or sports bras with built-in electrode pads, etc.).

For help selecting a HRM, see our article: Guide to DIY Heart Rate Monitors (HRMs) & Handheld ECG Monitors (Part I). Also take a look at Steve’s list on Amazon.com: Top Picks: DIY Heart Rate Monitors for A-Fib Patients.

Keep in mind: None of these DIY heart rate monitors are diagnostic tools. But they can be helpful once you know you have A-Fib, A-Flutter or suffer from PVCs, PACs, etc. Just don’t make medical decisions based on their readings. See your doctor if you have any concerns or symptoms.

Remember: None of these DIY heart rate monitors are diagnostic tools