I m a 19 year old girl. I ve been having irregular heartbeats since about 5 years and most of them have been quite subtle. Some have been severe, in the sense that I fainted. Just a few days ago, I had an arrhythmia which lasted for more than 15 minutes, and I suffered shortage of breadth, dizziness, extreme cramping pain in my entire body and since then I ve been feeling unusual fatigue and weakness in my body, shortness of breath most of the time and a funny feeling in my upper chest spreading to my jaw, not to mention the nausea. What is it ?