I'm sure you'll find out more from the cardiologist.
But, to give hope, there was a post a while back--and I'm sure Karlin will be able to remember the details and share -- about puppies having murmurs. Usually, since MVD is a progressive disesase, it doesnt show up in puppies. If there's a murmur, it could be the kind that will correct itself as your puppy grows.
I'm sure someone with more academic/scientific details can add to this idea.
Cedar (tri), Willow (blen), Holly (ruby), & Bella (blen)