I'm very sorry about this, but I wonder how much help we can be.
You see, your husband had several conditions, all of which were serious. Stents for aterial disease, a mitral valve (a replacement or a narrowing or a hardening?) involvement, which means the left side of the heart, the part that pumps to the rest of the body, a pacemaker (how much was his pacemaker doing? That is important information, too), his ventricular fibrillation
, and loss of consciousness
There would not have had to be neglect or error on the part of the hospital or doctor's staff for this to have happened. And walking down one flight of stairs should not have been the trigger of all that you describe.
While it is true that a subdural hematoma
is normally caused by a blow to the head (did he fall during his vf loss of consciousness?), it doesn't always have to happen that way, especially if the patient is of a sufficient age. The blood vessels that cross from the brain to the dura are most often very small and easily broken, and if he was on a blood thinner he could have had a small hemorrage that is called a "chronic" subdural hematoma, just leaking enough not to show symptoms until it was big enough to hurt him.
From what you say, Linda, this sounds natural.
While it is slightly surprising that he was not given a ct scan--ask your doctor why he was not--there may have been a reason. Find out.
However, from the work that he'd already had done it sounds as though medicine has given him more time with you than he would have had. That's not much help now, but it has given you more memories and happiness than you would have shared otherwise.
I am sorry for you and your loss.