<s>[INST] Hello doctor, I felt my heartbeat in my right shoulder blade for about 30 minutes and this concerns me. Is this heart related or stress related? Over the past three months I have had many EKG, echocardiogram and stress test, all were normal. Today I felt a very new and strange sensation while sitting down. My heart was beating fast for about 25 to 30 minutes and I felt it in my right shoulder blade and upper right chest. Please do not overlook because I am young and female. What could this be? Is it anxiety or stress or heart related? I am 40 and female. [/INST] Hi. The pounding or racing heart rate you are experiencing is known as palpitations, that is, awareness of one's own heartbeat. They usually are not serious and go away on their own. They may accur during physical or emotional exertion, anxiety, stimulants like caffeine, nicotine, alcohol. Unlike that if you have chest pain, shortness of breath, or dizziness or syncope, you need medical attention and evaluation. Some of the causes are listed here under: Anxiety, physical exertion, heavy meals, alcohol, coffee, smoking, medication like for cough or asthma, fever, dehydration, hypoglycaemia, hyperthyroidism, cardiac arrhythmias, cardiac failure, etc. So, now detail your history whether it is spontaneous or during exertion, or following any activity, fast regular or irregular, how many times a day, any associated with chest pain breathlessness or dizziness. ECG, hemoglobin, thyroid profile. After these tests according to the results further tests can be obtained. Stay chill, see if you are in any medication. Good sleep always helps. </s>