The conversation between human and AI assistant.
[|Human|] Sometimes my heart beats really fast and I can feel it thumping in my chest.  It feels like my heart is pushing through the chest walls.  This normally happens about twice a day and usually occurs when I am sitting.  It lasts about 15 minutes and then goes back to my normal rate.  Can you tell me the cause of this?
[|AI|]  Hello! Welcome and thank you for asking on Chat Doctor! Your symptoms could be related to anxiety. But, before coming to this conclusion, I would recommend consulting with your attending physician for a careful physical exam and some tests to exclude some other possible causes: - a resting ECG and a cardiac ultrasound-thyroid hormone levels for thyroid dysfunction- complete blood count for anemia-blood electrolytes for electrolyte imbalance- an ambulatory 24-48 hours ECG monitoring to examine your heart rhythm trends for a prolonged time and exclude possible cardiac arrhythmia. Hope to have been helpful! Wishing good health, 
