A healthy heart beats about 60 to 80 times each minute to pump blood throughout the body. The right and left sides of the heart work together (like two anatomically connected pumps). Blood that is low in oxygen first enters the right upper chamber of the heart. The blood flows from the right atrium to the lower chamber.
Oxygen-rich blood then returns to the left side of the heart. The blood flows from the left upper chamber to the lower chamber. From the left ventricle, the blood is pumped into a network of arteries (blood vessels) which carry the blood throughout the body. With heart failure, the heart's pumping power is weaker than normal, causing less blood to move through the heart and to the body.