Go to and read
http://talk.collegeconfidential.com/high-school-student-topics/2012842-how-to-become-a-doctor.html
After college and med school, you’ll spend 3 years in a pediatric residency, followed by I think 3 years in pediatric cardiology fellowship. (You wont be “merely” a pediatrician until you complete residency). Pretty much any US college can serve as a platform to get into med school. Where you go to college is less important than how you do in college. Med schools don’t care what you study in college. It can be bio, art history, Spanish, geography, etc. One needs to complete premed reqs. You should study what interest you as if you like material you’re more likely to do well GPA wise which is something med schools care, in part, a great deal about. Also consider studying something that offers you a Plan B should you change your mind. Most who start as premed never apply and chnage their minds, and of those that actually apply, to med school over 60% fail to start any med school. You wont be a pediatrician when you graduate from med school.
“My preferred career choice is …pediatric cardiology.” If you don’t mind how did you come to that conclusion?