dear Matty,
My daughter has heart disease and she has 2nd and 3rd degree heart block( that we recently were told needs a pacemaker).
Check out " pacemaker for 11 yr old" post. there is a website posted on it that will help you learn about RBBB.
As far as an echo, this procedure is very easy just like having a ultrasound when you were pregnant.But I don't really know if that would confirm a block diagnoses, as heart block is a problem with the electical system of the heart not the stucture.
keep us posted and good luck.
My thoughts are with you.