Hello and thank you for using HCM.I carefully read your question and I understand your concern. You should know that this palpitation has to do with a rhythm issue. There are some electrical impulses that generates from parts of the heart different from normal sinus rhythm.They cause premature heart contaction that its not a normal one. You feel like a skipped beat, anxiety, difficulties in breathing deeply and palpitations. There are different causes of this rhythm issue like simple emotional stress ,coffee and alcohol consumption or pathologys like anemia, hyperthyroidism, electrolyte imbalances or ischemic heart disease. The fact that you have already done a stress test and it results ok than you have excluded active ischemic heart disease. If I was your treating doctor I will recommend a full blood analyze to exclude anemia, hyperthyroidism and a holter rhythm monitoring to evaluate your rhythm tendency and the frequency of this rhythm issue. Only after this we can better judge what we are dealling whith and how to treat it. If we find a cause and treat it they might disappear.So don t worry just do what I mention before. Hope I was helpfull. Best regards, Dr.Ervina.