My Father recently had a coronary artery drilled to enable a stent to be inserted,but during the procedure the diamond tip came off the drill the doctor was using, it went with the blood flow blocking the artery that was being drilled causing my father to go into cardiac arrest.The doctor tried to remove the diamond tip but was unable.My father was transferred to a specialist hospital to treat him,this took around 40minutes,the specialists stented the artery and put the diamond tip into a side vessel which is still in the heart.For some reason they where unable to remove it.My father is 78 has been a no smoker and non drinker and fit for his age.This has left him with only 35 percent pumping action .He is on medication, will the heart recover from this at all? He is walking a bit everyday in the house but very tired and short of breath at times