<s>[INST] I have had a problem with my heart pounding very hard for over a month. It pounds so hard I see it in my stomach, and feel it in my neck and my vision flutters with my pulse. I had a cat scan on my stomach and ekg. They found nothing. What could it be? [/INST] Hello!Welcome and thank you for asking on HCM!I read carefully your question and understand your concern. I would like to know your physical constitution. Are you obese or thin? Your symptoms seem to be related to a metabolic disorder like possible thyroid dysfunction. Anxiety could also trigger this clinical situation. Have you measured your blood pressure lately? What are the values?Uncontrolled high blood pressure could also be the cause of your symptoms.I recommend performing some blood lab tests: -complete blood count-PCR, sedimentation rate (inflammation)-thyroid hormone levels (thyroid gland function)-blood electrolytes-kidney and liver function tests -cortisol plasma levels (adrenal gland function)-fasting glucose. You should discuss with your doctor on the above issues. Meanwhile I recommend you to closely monitor your blood pressure and heart rate (in sitting position after 10 minutes of total relax) and refer those values to your doctor. Hope you will find this answer helpful!Kind regards!Dr. Iliri </s>