Hello and thank you for using HCM. I carefully read your question and I understand concern. I will try to explain you something and give you my opinion. Heart flutters has to do with some rhythm issues in the heart. It might be different kind of rhythm issue like simple sinus tachycardia,meaning that your heart beats over 100 for minute. It might be what we call extra-systolic beats, that are premature heart contractions. Or, it might be a kind of arrhythmia like atrial fibrillation or flutter. All what I mention above might cause a fluttering sensation. The causes of this rhythm issues might be different to simple stress, excessive coffee or alcohol consumption or pathology s like anemia, hyperthyroidism, active infections, ischemic heart disease. So, first of all it is mandatory to exclude all above. If I was your treating doctor I will recommend a fool blood analyze and of course the holter monitoring. The holter monitoring is random, it might happen not to catch anything, so you can repeat it again to rise the possibility to identify what are this flutters. If we don t find anything again than you should not worry because its nothing serious, it might be just a little stress that cause this once a wile. Hope I was helpful. Best regards.