Congestive heart failure (CHF), a common, serious condition that occurs when the left side of the heart can't pump enough blood to the body, is a progressive disorder. Typically, CHF occurs when the lower chamber on the left side of the heart (left ventricle) does not fill or empty blood properly. People with CHF have symptoms such as shortness of breath, swelling of the legs, and tiredness. Before developing symptoms from CHF, many people have abnormal left ventricles that don't empty well. This condition is called asymptomatic left ventricular systolic dysfunction (LVSD).