Is heart failure a possibility at 20s? I'm worried about heart failure not family history of heart failure.
Heart Failure. Is heart failure possible in your 20"s? Well sure - but unless you have an underlying heart condition (congenital heart disease etc) then it's not really likely. If you are having symptoms then see your doctor for complete evaluation ASAP. If you're not having symptoms but still find yourself obsessing about the possibility, see your doctor for evaluation and referral for anxiety issues.
Anything's possible. But you'd probably need some heart problem that you were born with. And if that were the case you'd probably already know it. So, relax and enjoy life. You're 20, man! The World is yours! (And you're not sitting in 48 inches of snow)