The Mayo Clinic defines heart failure, also known as congestive heart failure and/or chronic heart failure, as the failure of the heart muscle to pump blood to the body adequately. In other words, heart failure is not a heart attack, and it is not death from heart disease, which its name might seem to imply.
Heart failure is a condition characterized by some or all of the following symptoms: shortness of breath, difficulty exercising, swelling in the lower extremities, and palpitations. The New York Heart Association (NYHA) has devised a widely used classification system based on these symptoms. The heart failure classes range from 1 (mildest form) to 4 (most severe form).
Heart failure can be of various types: left-sided heart failure in which fluid backs up in the lungs, right-sided heart failure in which fluid backs up in the abdomen and lower extremities, systolic heart failure in which the left ventricle does not pump out the blood sufficiently, and diastolic heart failure in which the left ventricle does not fill up with blood adequately.
Common causes of heart failure are coronary artery disease caused by atherosclerosis, a survived heart attack, high blood pressure, faulty heart valves, heart muscle damage caused by disease or infection, virus-caused inflammation of the heart muscle, and abnormal heart rhythms.