Eight Weeks Post Op

Today I took Kade to his eight week post-op appointment with our wonderful cardiologist, Dr.Pinto. They performed an Echo and an EKG and Kade's heart is functioning beautifully! Everything looks as it should in his chest- the VSD is closed and there is no leakage whatsoever (other than the remaining ASD's, which will close in time). I was so excited! Hoping that we would get a six month clearance and be one step closer to having just annual check-ups.
Well- my mother intuition told me that wasn't so and once again it was right. Kade hasn't grown. He hasn't gained even an ounce since his last check-up with Dr.Pinto. His cardiologist seemed concerned. Really, Kade eats a ton all the time-More than the average ten month old-so why isn't he gaining any weight? Dr.Pinto threw around the world metabolizing, hesitantly. She's just a cardiologist so it isn't her area of expertise.. His heart is healthy.
We have to go back in eight weeks. If Kade hasn't gained weight up to Dr.Pinto's standards, she will send us to a nutritionist as well as another specialist to find out if perhaps he has a syndrome (unlikely because he shows no other indicators, such as short limbs or developmental delays). If not a syndrome, I'm assuming we'll move from specialist to specialist until one of them can tell us why my Kadertot isn't growing as he should be. I'm beyond frustrated- I thought we were out of the woods but it seems we've just trailed the outskirts.

Any thoughts and prayers would be greatly appreciated.