Jeff is lucky his wife is a nurse. He should listen to you, but many men have problems with that. I know my husband does.

I know you will make him find the time to get to the cardiologist sooner rather than later

Will he allow you to go to the appointment with him?
I have to go with my husband when he goes for the physicals he needs yearly to renew his professional licenses, but I don't go in.

If he won't let you go, maybe he will allow you to scribble down a few notes to take with him? IDK, maybe that's asking too much?