Suggest you see a good Cardiologist. Irregular heart beats can mean cardiac arrthymia. This can go on for a long time until eventually it becomes serious. Talk to a endocrinologist or rheumatologist. Injuries especially sports injuries can cause inflammation in the bones and joint areas.
Summation go see a highly recommended endocrinologist.
The definition of cardiac dysrrhythmia IS what you have described. However, her recommendation of still another series of conventional medical specialists is NOT what I would recommend at this time. What you need is someone who sees things in patterns not professionals who only see things from their specialty. I would listen to Doc Dave for now. You have had sufficient conventional evaluation to be pretty sure that what is going on will not kill you very soon.