I’d agree, I’ve had a few generic Milanese straps and they’d always break in some way or start hooking into clothes when the edge got a little ragged, I’ve had a genuine Milanese loop for about 2 years now and it’s still as good as the day I bought it.
It appears you are correct and @whatwhat is wrong.
Apple today released watchOS 5.1.2, which enables the ECG app on Apple Watch Series 4 models. However, as Apple made clear, the ECG app is currently only available in the United States and its territories of Puerto Rico, Guam, and the U.S. Virgin Islands, preventing it from being used internationally at this time.
Many software features on Apple devices are initially limited to the United States, but international users have often been able to simply change their iPhone or Apple Watch region to the United States to gain access.
That's not the case with the the ECG app on the Apple Watch Series 4, though, as it only functions on models purchased in the United States. Those who live in and bought an Apple Watch in Canada, the UK, or elsewhere abroad can't use the region-switching trick to enable the ECG app — it doesn't work.
Note that the ECG app requires an Apple Watch Series 4 with watchOS 5.1.2, paired with an iPhone 5s or newer with iOS 12.1.1.
Really odd, I’m living in Sweden and haven’t done any changes but had no problem doing ECG’s. Working as expected here. Only thing that’s different is that I have my phone and watch languages set to US English.
Edit: oh another thing but I’m not sure that it has anything to do with it, the watch is bought in the US. Anyway didn’t expect being able to do ECG!