Congestive heart failure (CHF) is a chronic condition that affects the chambers of your heart. You have four heart chambers: two atria in the upper half of the heart and two ventricles in the lower half. The ventricles send blood to your organs and tissues and the atria receive blood as it circulates back from the rest of your body. CHF develops when your ventricles cannot pump blood in sufficient volume. Blood and other fluids back up inside your lungs, abdomen, liver, and lower body.