Hello erica and thank you for using HCM. I carefully read your question and i understand your concern. Don t worry, this is nothing serious and you are not having a heart attach. As you describe, my opinion is that we are dealing with a rhythm issue. Someone might feel fast and jumping heart beats for different reasons. It might be a sinus tachycardia, a supra ventricular tachycardia or what we call paroxysmal atrial fibrillation.This all are rhythm disturbances, electrical impulses generating from the heart which beats over 100 beat for minute, they might come and go. The heart might have its normal sinus rhythm or loos it and work in a chaotic way.All this rhythm issues gives you the sensation that your heart jumps and runs fast. You are not having a heart attack. A heart attach is manifested with a very heard chest pain and different complications. Yours are just rhythm problems. If i was your treating doctor i will recommend you to do some simple exams like a blood sample to look for anemia, hyperthyroidism. An electrocardiogram, echo-cardiography and a holter monitoring to see the rhythm tendency. After these we will have a better view. Don t worry because it might be just stress or if it is a rhythm disorder you can treat it with medications. Hope I was helpful. BEST REGARDS.