Credit: Slash Gear

The long-awaited ECG feature of the Apple Watch Series 4 may arrive in the final release of watchOS 5.1.2, according to a new report.

While ECG was announced during the launch of the Apple Watch Series 4, the capability didn’t ship with the new models. But according to an internal document obtained by MacRumors, the ECG feature will arrive in watchOS 5.1.2 — which is currently in its beta testing phase.

Benefits of ECG Capabilities

The ECG (electrocardiogram) capability of the new Apple Watch models will allow users to take an on-the-spot ECG reading using their wearables. Essentially, an ECG measures the electrical activity of the heart, which can detect a variety of cardiac issues.

Notably, it’s the first consumer-facing device to sport such a feature and it’s also the first ECG-type device to be sold without a prescription.

That could allow users to help detect irregular heart rhythms, including those that are a symptom of atrial fibrillations. The data can then be stored in the Health app on a connected iPhone. From there, users can share that information with their doctors or other healthcare practitioners.

How Does It Work?

While all Apple Watch Series 4 models sport the Apple-designed ECG sensor, the launch will be limited to the U.S. initially — largely because it’s the only region where Apple has obtained regulatory approval. In this case, the ECG Apple Watch sensor is FDA-cleared.

There is, however, a workaround for users in other countries who would like to try the feature out for themselves (when it launches in the U.S., of course).

The reading itself takes about 30 seconds. Users will take an ECG reading by placing a finger on the Digital Crown.

The internal document does advise Apple staff to inform customers that the ECG app is “not intended to be a diagnostic device or to replace traditional methods of diagnosis.” In addition, Apple says it “should not be used to monitor or track disease state or change medication without first talking to a doctor.”

On a similar note, another Apple internal training document indicates that watchOS 5.1.2 could introduce and enable irregular heart rhythm notifications for Apple Watch Series 1 through Series 4 models.

Compatibility and Release Date

The ECG feature, however, will only be available on the new Apple Watch Series 4 devices. Additionally, Apple indicates that a paired iPhone must be an iPhone 5s or later running iOS 12.1.1 — which will likely be released alongside watchOS 5.1.2.

It isn’t currently clear when watchOS 5.1.2 will be released. But since the beta testing period kicked off on Nov. 7 and it’s a relatively incremental update, it will likely be rolled out sooner than later.

Of course, it’s worth noting that it’s perfectly possible for the ECG feature to be pulled from watchOS 5.1.2 before its release. We’ve seen that happen to several features on iOS in the past year or so.