Heart failure is a chronic condition that affects the heart’s ability to pump enough blood for your body's needs. The most common cause of heart failure is damage to the heart muscle from a heart attack, or from blockages in the arteries around your heart. However, heart failure can be caused by other conditions, including high blood pressure, heart valve problems, or congenital heart disease. Measuring the percentage of blood that pumps from your heart to your body after each contraction (your ejection fraction) helps to identify the type of heart failure you have.