Heart defibrillator isn't successfully connected during surgery

A fellow caregiver asked...

My father has had three heart attacks, numerous stents and open heart surgery. This has caused his heart to only work at 18%. A new cardiologist insisted he was in need of a heart defibrillator. However after the surgery he notified my dad that he was unable to connect the device to the back part of his heart where is was needed and he would have to see a heart surgeon. But he left the defibrillator in somewhat hooked up and he said that the device would still work the same. I really need advice on what my dad should so now and is it alright leaving the device in? Will the device still work? What type of procedure will be needed to correct this so it can reach the back side of the heart? Also I was also curious to know should've the doctor have known the condition of the heart and the vessels around it? Thanks in advance for any information given.