At their September event Apple announced a new health-focused watchOS app, an Electrocardiogram, or ECG, detection app. At the time Apple indicated that it would be available “later this year” and would be available only in the United States, at launch. With the release of watchOS 5.1.2, the ECG app is now available. I thought I would go through the setup and features of the ECG app.

Before we dive into the features and set, there are some requirements in order to use the app. The first requirement is that you have a Series 4 Apple Watch. This is because the sensors are only available on the latest Apple Watch. The second requirement is that the Apple Watch is running 5.1.2. This is the version that has the ECG app. The last requirement is that the iPhone paired with the Apple Watch must be running iOS 12.1.1, build 16C50.

Once you have met all of these requirements, you should have the ECG app available on the Apple Watch. When you tap on app you will be presented with an image like the one below, that indicates to do setup in the Health app on the iPhone. If you open the Watch app on the iPhone, and tap on the “Heart” app, you will see something similar to the screen below. This provides a quick link to open up the Health app.

Once you open the Health App you will be presented with a popup that asks if you want to setup the ECG app. If you press “Set Up ECG app”, you will be prompted for your birthdate. This is needed because the ECG app is not designed to work for anyone under 22. This is because it is the ECG app is not considered a pediatric app. 

After you set your birthdate and click on the “Continue” button. The next set of screens will provide information about what an ECG is and how the app works, the results you will see, and what the app cannot tell you. Let us start with what the test cannot tell you.

What it can detect

The ECG app can provide a few different types of results. These results include the Sinus Rhythm results, Atrial Fibrillation (AFib), Low, or High, heart rate, or an inconclusive result. A Sinus Rhythm result indicates that the heart rate is consistent. 

If Atrial Fibrillation is detected, it means that your heart is beating with an irregular rhythm. 

If you receive a High or Low heart rate result, it means that the ECG app cannot do proper detection and the test should be re-done at a later time after your heart rate has come back into normal range.

An inconclusive result means that something went wrong with the detection, typically the Apple Watch is too lose or you moved your arms too much during the testing.

What it CANNOT detect

The ECG app is limited in what it can tell you. It cannot tell you if you are having a heart attack. The ECG app cannot detect a blood clot or stroke. Additionally, the app cannot detect other heart issues, like high cholesterol, congestive heart failure, or other forms of arrhythmia. If you are experiencing any symptoms, you should see your doctor.

Limitations of the ECG app

How the app works

The ECG app works by using a pair of sensors. These sensors are  the electrical heart sensor on the back and the digital crown. To use the actual app, you open the app on the Apple Watch you are presented with an animated heart icon. The text below the heart says “Hold your finger on the crown.”, meaning the Digital Crown.

When you place you finger on the digital crown it creates an electrical circuit between the back of the Apple Watch and the digital crown, with your body as the conductor between the two. When you place your finger on the Digital Crown you will need to keep it in place for 30 seconds. During this time it is best to not move your arms so that an accurate reading can be obtained.

Once the test is concluded you will receive results on the Apple Watch. The results will be one of the ones mentioned above. If it is a Sinus Rhythm result, your heart rate for during the test will be displayed on screen. 

After the results are shown on the screen you can add some additional information, like symptoms you may be experiencing. This is a nice addition to be able to add any symptoms so that you can later look at it to recall how you were feeling when you took the ECG reading. When your results are finished they will be added into the Health app. Here you can see all of your past results as well as export the results into a PDF to provide to your health care provider. 

Closing Thoughts

The ECG app on the Apple Watch is a great addition to add to the health aspects of the Apple Watch. While the ECG is currently only available on Series 4 Apple Watches that have been purchased in the United States, it is possible it will be available in more countries after they get regulatory approval in those countries. 

The fact that a device on your wrist can detect a heart condition that you may not have been previous aware of, means that you may become aware of an issue before it becomes a serious problem. There has been one reddit user who has already experienced this and the doctors indicated that it was a good thing that the user came in when they did, otherwise they might not be around to tell the tale.