My newborn has diagnosed with 1.3mm hole

Doctor told she has 1mm hole between upper chambers, not in muscle so unlikely it will close itself. I am so much worried please help. But also told not to worry, while discharging from hospital after 3days, pedestrian told and referred to cardiologist.

Edit: Perimembranous Ventricular Septal Defect (VSD) - bidirectional shunt, and unusual course of the right coronary artery,

Edit2: 3mm hole, cardiologist confirmed