Heart Failure Support Group
Heart failure is a condition that can result from any structural or functional cardiac disorder that impairs the ability of the heart to fill with or pump a sufficient amount of blood throughout the body. It is often undiagnosed due to a lack of a universally agreed definition and difficulties in diagnosis, particularly when the condition is considered "mild."
You really haven't said why you suspect heart failure, is he a heart patient? You might try going to the ER or Urgent care and see if someone will give him a serious once over, especially if he's experiencing some of those other symptoms.
I remember going in and they thought my only problem was pnuemonia, turns out I was having a heart attack, had Congestive Heart Failure, failing mitral valve, and assorted other problems they overlooked. You have to go with your gut and fight.
Good luck