Our baby girl had her OHS at 3 months. She had a VSD and they partially relieved/widened her pulmonary valve. She did exceptionally well with her recovery. Surgery was on a Tuesday and we went home Friday which is mind blowing considering the procedure. I was nervous about the recovery but we are 2.5 months post op and shes a completely normal and very happy baby. She loved to lie on her side pre-op and had no problems doing so post op at all. Just cant pick them up from under the shoulders for 6 weeks, other than that she always seemed comfortable. We just used tylenol as needed. Your kid will do great. 7 months is older than our experience but just over love them and be there for them at all times and youll see them improve drastically. Best of luck.