Can an ecg change within 2 months? Last time i had one, (around 2-3 months ago) i weighed 90 pounds, (19 yr old female, 5'2, non smoker) and had symptoms of heart disease, my doctor said it was anxiety, however lately iv been getting symptoms like pressure mainly on my left side of chest, (sometimes in the middle-rarely), with shortness of breath, and a weird feeling in my left arm. Happens about 5 times per day, and the pain lasts seconds. Iv been having this pain for about a week and a half now. Is it heart disease? Also, can a CBC detect hear disease/failure? Im going to my family doctor tomorrow.