Since most of your test results pointed towards 'a healthy' heart, I would be optimistic that perhaps antibiotics
or other treatment would help.
When we fear heart trouble, it can
anxiety. I hope that you can relax somewhat and wait until further info comes in. Hopefully your only heart issues are your heartrate ( brady/tachy), and the coated PM takes care of that, and Dr's resolve possible infection. Good luck, and keep us posted.