Name of 70's/80's Horror movie opening with a woman dying on a hospital bed

I remember my dad having taped over this movie on a tape I found as a kid but I've always been curious what movie it is. Granted I could be remember wrong since it was 30+ years ago but this is what clues I have.

The movie I believe had a one-word medical title like "Diagnosis" or "Prognosis" or "Flatline" or something, but I am not sure as it was only visible for a frame or two.

The first scene was a woman lying on a hospital bed in a dark room. It's pretty much total blackness all around her. She then starts writhing around in agony and dies. I think it has a shot of a monitor flatlining.

It then cut to a morning-after love scene between a young couple where the guy had a beard and both are in bed. They both have their clothes on still if I remember correctly.

Any ideas? I have no idea if it was a TV-movie or an actual theatrical film but I imagine it was pretty obscure, and from somewhere between 1978-1989.