Info-tech

ECG goes live on Apple Watch in India

Mala Bhargava New Delhi | Updated on September 20, 2019 Published on September 20, 2019

Apple has now activated the ECG and irregular heart rhythm detection for use in India. The ECG feature will work on Apple Watch Series 4 and 5, while the irregular heart rate detection is on watches from Series 1 onwards since they have the optical heart sensors. These capabilities have been available in the US since December 2018 and are now being enabled in select countries.

Located on the wrist-facing side of the Apple Watch Series 4 and 5 are electrodes built into the back crystal. Where an ECG taken at a hospital will involve the use of twelve leads, the Apple Watch will execute a single-lead reading. This wrist ECG does not equate to being tested at a lab but is rather indicative and expected to be helpful for discussions with medical professionals.

“We are confident in the ability of these features to help users have informed conversations with their physicians,” said Sumbul Desai, MD, Apple’s vice president of Health.

“With the ECG app and irregular rhythm notification feature, customers can now better understand aspects of their heart health in a more meaningful way.”

To use the new heart related features, users will need to make sure their watch is running the WatchOS 5.1.2 or later operating system. Users should also have upgraded their iPhones to the latest iOS13 version with which updates will bring in the ECG app and enhancements to the Health app.

How to use?

To take an ECG recording at any time or after an irregular rhythm alert, users launch the new ECG app on Apple Watch and place the finger of the other hand on the ‘Digital Crown’ or the small round knob on the side of the watch. The hand wearing the watch must rest on a surface and the user must remain still. As the user touches the crown, the circuit is completed and electrical signals across the heart are measured. After 30 seconds, the heart rhythm is classified as either AFib (Atrial Fibrillation), sinus rhythm or inconclusive. Apple has from the start focussed specifically on AFib, the problem being the most common type of irregular heart rhythm and a condition that can lead to strokes.

The recordings are visible in the app as the type of graphs that are familiar from formal EGG tests and a PDF or printout of these can be taken for a consultation with the doctor who or may not advise full ECG or other tests.

With the upcoming upgrade to watchOS 6, the irregular rhythm notification feature will use the optical heart sensor will do occasional heart rhythm checks in the background for signals of an irregular rhythm that appears to be Afib. If an irregular rhythm is identified on five checks over a minimum of 65 minutes, an alert will go out to the user who should proceed to get a check up.

According to Apple, the ECG app’s ability to accurately classify an ECG recording into AFib and sinus rhythm has been validated in a clinical trial of 600 participants who were tested on 12-lead ECG and the Apple Watch.

The study found the ECG app on Apple Watch demonstrated 98.3 per cent sensitivity in classifying AFib and 99.6 percent specificity in classifying sinus rhythm in classifiable recordings. In the study, 87.8 per cent of recordings could be classified by the ECG app. With the heart rhythm feature has only now having been enabled in India, it remains to be seen whether doctors and patients manage to use the data to aid discussions.

Published on September 20, 2019
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