Why the ECG in the New Apple Watch May Not Be So Great After All

Apple Watch ECG
Image: Apple

Apple’s heart-rate monitor is meant to give people warnings if their heart rate goes too high or low and let them take a readout of their heart’s electrical activity. While it’s being billed as a big improvement, critics say it will lead to large number of people getting wrong reports on their heart.

Read more Apple Watch 4 Fall Detection Turned Off by Default, Here’s How to Turn it On

An ECG (also called an EKG) is typically performed by putting electrodes on the skin to detect the electrical changes that arise from the beating of one’s heart. The Apple Watch 4 has both the ability to perform an ECG and to detect irregular heartbeats, but some are questioning whether the application is sufficiently accurate to perform these tests safely.

Although, Apple claimed it to be the “first-ever ECG app offered directly to consumers” at its iPhone launch event this week, it’s not so. It was AliveCor’s ECG which was cleared by the FDA last year. Unlike that device, Apple’s heart rate tracker will be built in for everyone who buys the wristwear, raising concerns about false positives as well as unnecessary treatment with potentially dangerous drugs, including blood thinners, reports Wired.

“I’m generally all for patients having access to more information about their health. I’d have a hard time saying functionalities like this should be suppressed,” says Adam Cifu, a professor of medicine at the University of Chicago, who published a paper on the potential impact of the AliveCor product and other smartphone atrial fibrillation tools. “On the other hand, I’m very concerned because this will certainly cause false positives. We’ll be finding people getting warnings about arrhythmias they don’t have, that will cause anxiety in people.”

Apple Watch ECG
Image: Apple

Any time you undergo medical checkup, you have to address the risk of both false positive and false negative test results. When you don’t have a certain health problem, but your health report says you do, that’s a false positive test result. On the other hand, a false negative is a test result that says you don’t have a medical problem but in reality, you do. Both can be harmful or, at the very least, sub-optimal or incomplete medical treatment for an ongoing condition.

Read more Wearable ECG Monitoring Patch Can Detect Atrial Fibrillation Earlier and More Efficiently, Says Study

Another feature, the heart rate monitor – which works via sensors built into the back of the watch face – may also have potential for false alarms. For example, some people experience panic attacks, when stress causes faster heart and breathing rate.

While ECG isn’t a common feature in smartwatches, heart rate monitors have been a common part of many wearable devices. However, it should be viewed as a screening tool rather than medical diagnosis. It wouldn’t be wise to rely on heart scan results that was delivered by a smartwatch sensor.