I had bad side effects with Mavacamten and also with Aficamten in a clinical trial. It seems that "cardiac myosin inhibitors" do not agree with me. I did not realize that was the comon demoninator when I signed up for the double blind study. I am back to my metoprolol and feel much better than I did when I was on those 2 drugs. It's not for everyone. No more experimenting for me. 2 1/2 years of pure hell.