Hello and thank you for using HCM. I carefully read your question and I understand your concern. I will try to give you me my opinion. As you explain, you feel rapid heart beats, feeling tired or fainting. My opinion is that we have to check for possible rhythm issues. If it is a rhythm problem it is important to catch it, as this are random episodes. Sometimes arrhythmia like supra ventricular tachycardia, atrial fibrillation, extra-systolic beats might be the cause of this symptoms. As you mention, you have already done all the examinations, blood samples and this result fine. This is a very good thing. We are sure that there are no problems like anemia. I will like to remember you to check your thyroid hormones because sometimes they might be responsible of rhythm problems. I will also recommend a holter rhythm monitoring for 48 h to increase the possibility to catch anything. I don t know if you had done it before, but you might repeat it for a long time. If the blood analyze, your cardiac echo and the holter monitoring for 48 h result normal than you have nothing to worry about. It might be just a stressed period. Only if we catch an arrhythmia we can know how to menage it. Hope I was helpful. Best regards.