Could Stabbing Pain In Breast Be Due To Arrhythmia And Mitral Regurgitation?

Hello Im a girl of 23yrs old. Last year i was reported to have mitral regurgitation 1rst stage. late March last year at around 2am or even 6am i started having stabbing pain in my left breast and sternum region which lasted for a maximum of 15mins. I went to cardiologist she said i have arithmia and mitral regurgitation stage 1. I stopped taking her meds for a long while. Now I m having little pain in the same pain zone (between left breast and sternum) but no breathlessness. Please help me out any suggestions are welcomed. Thank you.