The basic connection between COVID and heart is well understood I think. Aa I understand it one effect is the spikes plug into ACE receptors which cause construction of capillaries to the point flow stops and the single file of blood in there coagulates. The famous black “COVID toes” is a visible manifestation. The Moderna “Spikevax” programs your tissue to manufacture the spikes only. The quantity varies by person. These spikes act the same and cause vasoconstriction which also varies by personal sensitivity. Anti coagulation drugs I think are very important with aFib. I was on them when I stupidly took the booster and heart went crazy anyway. I asked a doctor why she didn’t prescribe at least an aspirin to folks getting vaccinated and she said anything that might be construed as causing vaccine hesitancy was severely discouraged.
Off label prescription of angiotensin II blocker meds like Micardis is happening, but I wonder if this is the actual mechanism of heart damage. I still am trying to learn whether damaged heart nerves will regenerate or not. Of course I don’t really know if that’s what I have.