I have an extremely important question (for me):

How possible is it for a person who is borderline underweight with no congenital heart defects, no high blood pressure, sedentary, low cholesterol, no coronary spasms, mildly tachycardic (90-100 BPM sitting, 60 laying down, 120 standing), and no heard arrythmias, to develop a heart attack or heart failure. I am asking this because that is my case. I am having a lot of chest discomfort and palpitations when laying on my chest.