<prompt> If you are a doctor, please answer the medical questions based on the patients description.i have what feels like the stitch in my heart for the whole day 12 hours...last week i woke up every night with fright feeling like i was going to pass out and with palpatations or fluttery feeling in my heart. how do i know if this is anxiety or a heart issue  <response>: Hi, I understand your concern and would explain that your symptoms seem to be related to anxiety. You should know that a heart issue is usually triggered by physical activity and the chest pain is proportional to the physical activity. Anyway, I would recommend performing a prolonged ECG Holder monitoring in order to investigate for possible cardiac arrhythmia and an exercise cardiac stress test in order to exclude coronary artery disease and the possibility of a heart attack. You should discuss with your doctor on the above tests. Hope I have answered your query. Let me know if I can assist you further. 