if you are primarily interested in doing kids, then i don't think you need a combined program. most pediatric fellowship grads i've worked with do pedi hearts too. the only real advantage to doing an adult cardio fellowship, imho, is that you get the TEE cert too. otherwise, this doesn't really put you on a pedestal in the OR... yet (i.e. unless they make the cardio fellowship an ACGME accepted year). just my $0.02.