I'm giving you two links. The American Heart Association and the one to CHF Patients.com.
His diet is very important. No/Low sodium as specified by the doctors. Check his legs, ankles, shins for swelling. If you see much/see it change call the Doctor. If he has trouble breathing take him to ER- this can manifest itself as a
cough, not necessarily a big one.
Read up on the web sites. They discuss medications and treatments. Look at his medication list and what they say should be standard treatment.
I am a CHF patient with left ventricle failure and can attest to the VERY STRONG correlation between sodium intake and swelling. He must conform to that aspect of diet. By the way, fruit has no sodium.