Cardiac arrhythmia twice this month to the point of hitting the floor face first. How does one talk about this with HR/PM?

A doctor first

I have arrhythmia since birth and have lost a job because of it (I fainted and my boss did not believe I had a heart disease). I tend to faint once every two months so when I got my current job I knew that I had to inform them so they wouldn't freak out when it happens. It wasn't easy to tell my PM but he was understanding. He understands that I can't take much stress and working after hours could be dangerous for me. I have been working there for 1.5 years and during this time I have fainted 4 times. My PM partly blames himself although it wasn't his fault, it's just something that happens to me. He just asked me to alwasy tell him if I was feeling unwell because he is responsible for me.
I hope this helps :)
Best of luck to you

@FreezaPlanet419 thanks for input. Great advice