After a few years in limbo, Apple has finally been able to activate the electrocardiography (ECG) capabilities in the Apple Watch Series 4, Series 5, and Series 6.
As part of the release of the latest iPhone operating system, iOS 14.5, the Apple’s WatchOS 7.4 means that this long-awaited feature can now be used to test the timing and strength of the electrical signals that make the heart beat.
Greenlit by The Australian Therapeutic Goods Administration (TGA) earlier this year, but only activated by Apple with the newly released operating system update, the Apple Watch ECG allows the device to essentially perform an electrocardiogram to show whether or not the upper and lower chambers of your heart are in rhythm.
This can detect various potential issues, including atrial fibrillation (that is, AFib). Apple Watch ECG readings are sent to the connected app and can be turned into a PDF that you can share with your doctor. As with all proactive health software on the Apple Watch (and all other fitness watches), the readings are to treated as informational feedback.
TGA have even said, in an official statement when they first greenlit Apple Watch ECG feature, that users are not to take “clinical action” based on the app’s readings.
The ECG reading involves many LED and light-sensitive photodiodes that examine the blood flow in the wrist on which the Apple Watch is placed.
Blood is red due to its absorption of green light, and the reflection of red. Green light is better absorbed when the heart beats, and is noticeably lesser between beats. The LED lights are flashed hundreds of times per second to use this information and calculate the heart rate as a result.
WatchOS 7.4 also brings other important functionality to the newer Apple Watch models. You can now use the device to securely unlock your iPhone (X and later models only), meaning you won’t have to rely on Face ID if, for example, you’re wearing a mask.
There’s also now the option of classifying Bluetooth device type in settings for correct identification of headphones for audio notifications. In addition, you can stream audio and video content from Apple Fitness+ workouts to AirPlay 2-enabled TVs and devices.
Interested in learning more about watches for active lifestyles? Check out our list of 20 great sports watch options at a range of different price points.