Yes. Congestive heart failure occurs when the heart has been damaged and is no longer a strong enough pump to deliver adequate amounts of oxygen to body tissues. Circulation backs up, leading to fluid retention in the body and /or lungs, and oxygen-starved organs cannot function normally. The air we breathe contains only 21% oxygen, which is plenty for those who have a normally functioning heart, but is sometimes not enough for those with a weakened heart.   If you have congestive heart failure, increasing the amount of oxygen in the air you breathe can help your heart and lungs meet the metabolic needs of your body.  Oxygen is often prescribed when symptoms of increasing oxygen starvation (shortness of breath, fatigue) occur, or when the measured oxygen level in your blood is lower than normal.