###Human: Is the sharp pain that I experienced on my left armpit, a sign of heart attack? ###Assistant: Hi. I understand your concern as your grandparents passed of a heart attack, the fear you have is genuine. But, just pain in your chest is not an indication of a heart attack. Since you gave a history of carbonated food and tablet Amoxicillin along with thyroid medication, these both can cause an acid reflux and that can cause heartburn and lead to such non-specific pain. However, if the pain was associated with sweating and stabbing character or constricting type with radiation to the left arm, then it is always better to get an ECG done to see if it is related to your heart. Heartburn. ECG. For further information consult an internal medicine physician online.--->