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Feature Articles

ECG is now available on the Apple Watch in SG and here’s what you need to know

By Kenny Yeo - 27 Jul 2019

ECG is now available on the Apple Watch in SG and here’s what you need to know

Note: This article was first published on 23 July 2019.

It's finally available in Singapore!

ECG is finally available in Singapore?

It’s been a long wait but the ECG function will finally be enabled on Series 4 Apple Watches purchased in Singapore via a watchOS and iOS update.


Why did it take so long?

To enable this feature, Apple is required to get approval from regulatory bodies in Singapore such as the HSA (Health Sciences Authority). Who, in turn, have to ensure that the feature works as advertised. All of this takes time.


Fair enough, but what’s an ECG exactly?

An ECG provides insights on the regularity of your heart beat rhythm.

ECG (or EKG) stands for electrocardiogram. It measures the electrical activity of the heart by plotting a graph of voltage against time. From the graph, doctors can determine if your heart rhythm is normal and also see if there are any irregularities that need further investigation.


What do I need to get it to work?

You need the latest Apple Watch — the Apple Watch Series 4. If you do, you then need to update watchOS on your Apple Watch and iOS on your iPhone to get the ECG app.


Why does it only work with Apple Watch Series 4?

ECG only works on the Apple Watch Series 4.

Taking an ECG requires hardware that only the Apple Watch Series 4 has. There are electrodes built into the caseback and Digital Crown that enables the Apple Watch Series 4 to take an ECG. Older Apple Watches don't have these electrodes.


Ok, I’ve updated my watch and phone, how do I get started?

You only need to enter your birth date to get started.

Open the Health app on your phone and you should see a prompt to set up the ECG app. If you get a prompt, you can manually set it up by heading to Health Data > Heart > Electrocardiogram (ECG).


Now what?

The ECG app icon looks like a heartbeat line.

You can start taking your first ECG! Simply go to your watch and launch the ECG app. It's an icon with a heartbeat line.

To start, place a finger using your opposite hand on the Digital Crown. It takes about 30 seconds to get a reading. And as the app says, you should keep your hand still, so I recommend doing this on a desk or any other solid surface. Don't worry, you won't feel a thing during the test. Also, Apple states that the ECG app is not intended for use by people under 22 years of age.


Why do I have to be at least 22 years old?

That's because of FDA (U.S. Food and Drug Administration) regulations. Your heart rate and rhythm is partially dependent on your age (toddlers and teens have higher heart rates) and the Apple Watch's ECG function has only been tested to work well for people above 22.


How accurate is it?

Considering its just a watch, it’s pretty accurate. Clinical studies conducted by Apple found the ECG app to demonstrate 98.3% sensitivity in classifying AFib and 99.6% specificity in classifying sinus rhythm in classifiable recordings. To understand the study in greater detail, you can read the white paper here.


How do I make sense of the results?

It's easy to get an ECG reading. Launch the app, then stay still and hold onto the Digital Crown for 30 seconds. And voilà! That's it.

There are four possible results: sinus rhythm, atrial fibrillation, low or high heart rate, and inconclusive. Because I’m no doctor, I’m attaching Apple’s interpretation here:

  • Sinus rhythm — A sinus rhythm result means the heart is beating in a uniform pattern between 50 and 100 BPM. This happens when the upper and lower chambers of the heart are beating in sync. A sinus rhythm result only applies to that particular recording and doesn’t mean your heart beats with a consistent pattern all the time. It also does not mean that you're healthy. If you're not feeling well or are feeling any symptoms, you should talk to your doctor.  
  • Atrial fibrillation — An AFib result means the heart is beating in an irregular pattern between 50 and 120 BPM. AFib is the most common form of serious arrhythmia, or irregular heart rhythm. If you receive an AFib classification and you have not been diagnosed with AFib, you should talk to your doctor.
  • Low or high heart rate — A heart rate under 50 BPM or over 120 BPM affects the ECG app’s ability to check for AFib, and the recording is considered inconclusive. A heart rate can be low because of certain medications or if electrical signals are not properly conducted through the heart. Training to be an elite athlete can also lead to a low heart rate. Learn more about low heart rates from the American Heart Association. A high heart rate could be due to exercise, stress, nervousness, alcohol, dehydration, infection, AFib, or other arrhythmia. Learn more about high heart rates from the American Heart Association.
  • Inconclusive — An inconclusive result means the recording can’t be classified. This can happen for many reasons, such as not resting your arms on a table during a recording, or wearing your Apple Watch too loose.

You can export your results as a PDF for your doctor. It'll look something like this.

Unless you are trained to read a graph like the one above, it goes without saying that if you feel that something is wrong or you don’t feel well, you should consult a doctor as soon as you can. You can access all your ECG readings through the Health app and it can even be exported to a PDF for easy sharing with your doctor.


How can I get the best results?

Apple recommends the following:

  • Rest your arms on a table or in your lap while you take a recording. Try to relax and not move too much.
  • Make sure that your Apple Watch isn’t loose on your wrist. The band should be snug, and the back of your Apple Watch needs to be touching your wrist.
  • Make sure that your wrist and your Apple Watch are clean and dry.
  • Make sure that your Apple Watch is on the wrist that you selected in the Apple Watch app. To check, open the Apple Watch app, tap the My Watch tab, then go to General > Watch Orientation.
  • Move away from any electronics that are plugged into an outlet to avoid electrical interference.


Can I let a friend/relative/colleague take an ECG reading?

Thankfully there were no nasty surprises while testing the ECG app for this article.

You can but it is important to stress to them that they should seek help from a doctor if they are feeling unwell. Taking an ECG reading using the Apple Watch is no substitute for a visit to the doctor.


Anything else I should know?

The ECG app is handy and definitely a killer feature of the Apple Watch. But it isn't a definitive verdict of your health and you should definitely see a doctor if you are feeling unwell.

As accurate as the ECG app and the Apple Watch Series 4 may be, I must stress once more that its results are not a definitive verdict on the condition of your heart and that it’s no substitute for a doctor.

It’s also important to note that the ECG app cannot detect the following:

  • Heart attack
  • Blood clots or stroke
  • High blood pressure
  • High cholesterol
  • Congestive heart failure
  • Other forms of arrhythmia

What it can do, however, is provide a doctor and you with additional insights about your health. Long-term insights are invaluable to doctors as symptoms do not always present themselves in the doctor’s office. Furthermore, there have been numerous real-life examples (1, 2, 3) of how the Apple Watch has helped its wearers detect heart conditions that they were not aware of. At the end of the day, if you are feeling unwell, please seek help from a doctor.

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