The Apple Watch Series 4 was one of the only fitness trackers that could take and echocardiogram (ECG) without the need for any additional apparatus. That functionality is now finally available in India to notify users of irregular heart rhythms.
The Apple Watch Series 4 had the functionality and necessary hardware built-in, but had to be certified for use individually by each country’s authorities, and match the certification and clinical data standards. That regulation has finally been met and starting today, the ECG app and irregular heart rhythm notification will be available for users in India.
How does ECG on an Apple Watch work?
The new Apple Watches have electrodes built into the back crystal as well as the digital crown. To take an ECG reading, the user has to simply launch the ECG app and hold their finger on the digital crown which completes the circuit and electrical signals across their heart are measured. After about 30 seconds, the measurement classifies the heart-rate as either atrial fibrillation (AFib), sinus rhythm or inconclusive, and stores the more detailed readings and symptoms in the Health app on an iPhone. These can directly be shared with doctors as a PDF.
Not just that, the Apple Watch will also now periodically use the optical heart rate sensor and look for signs of irregular heart rate that may seem like Afib. If this happens over five times in the next 65 minutes, a notification is generated to alert the user.
To ensure that Apple’s readings are accurate, the company held a clinical study with around 600 participants, where the Apple Watch exhibited a 98.3% accuracy and a 99.6% specificity in classifying sinus rhythm.
While taking an ECG, the Watch explicitly mentions that heart attacks are not detected by it, serving as a reminder to consult a physician for any inconsistency in the heart rate. Apple’s focus on making the Apple Watch more than a smartwatch, into a one-stop fitness solution gets even more clear with this new functionality.