Thanks for your question on Healthcare Magic. I can understand your concern. No need to worry for heart diseases as your ecg and Holter monitoring were normal. Stress and anxiety can also cause similar kind of fluttering sensations. So consult psychiatrist and get done counselling sessions. Try to identify stressor in your life and start working on its solution. You may need anxiolytic drugs too. Don t worry, you will be alright with all these. Avoid stress and tension, be relax and calm. Hope I have solved your query. I will be happy to help you further. Wish you good health. Thanks.