ECG function on Apple Watch 4
why my new Apple Watch 4 didn’t contain the ECG app on it?
Apple Watch Series 4, watchOS 5
Your watch already contains the ECG hardware, but it is not enabled by default because Apple must comply with national laws in each country where it sells products. If it is available at your location You need to set it up as described in Apple’s support document Taking an ECG with the ECG app on Apple Watch Series 4 - Apple Support
