Atrial fibrillation monitoring

I have recently had open-heart surgery for a new aortic valve, and have an ongoing issue with intermittent atrial fibrillation. On recommendation of both of my cardiologists, I bought an Apple Watch Series 6 so I can be alerted when this is occurring, particularly so I can sit down if walking, etc.

As I am trying to set this up, a question comes up: have you been diagnosed with atrial fibrillation. If I check “yes,” I’m told I can’t use this feature.

So I could just lie to the app, or return the Watch. The ECG is a useful feature, but isn’t constantly monitoring.

Is there a workaround? (And yes, I live in the USA.)