Hello Baby 8 months old, echocardiogram: coronary-pulmonary fistula 1…

Hello Baby 8 months old, echocardiogram: coronary-pulmonary fistula 1 mm. O.O.O. T.R. 1 degree. L.R. 1 degree. Please share your experience if any of your children had such a diagnosis. I'm writing to see a doctor only tomorrow, I'm sitting and worrying all weekend. The baby is behaving as usual, this is the first echocardiogram for all 8 months. Is it scary? How long does it take to treat and so on, please share your experience ?? Still breastfeeding, does it affect anything like that? Thank you all