I'm 21 years old. My heart is fine, I've been to 4 cardiologists in the last year. I'm healthy, but i have a horrible panic disorder. I'm overweight, but i eat very healthy and im on cholesterol medicine. (I have 152 cholesterol) When going up the stairs (12 steps) my heart beats like crazy, about 140 bpm, but then slows down after a minute or so. Is this normal???