Aging alone does not cause heart failure. But older people are more likely to have the most common causes of heart failure, which are long-standing high blood pressure and heart attacks (due to coronary artery disease).

Disorders can cause heart failure in two ways. They can cause problems with the heart's ability to

• Fill with blood

• Pump blood out

Among older people, filling problems (called diastolic dysfunction) and pumping problems (called systolic dysfunction) are equally common.

Filling problems

Filling problems usually occur because the walls of the ventricles have become stiff. As a result, the ventricles cannot fill with blood normally, and too little blood is pumped out. As people age, heart muscle tends to become stiffer, making heart failure due to filling problems more likely. High blood pressure can cause filling problems because it makes the heart muscle thicker and stiffer.

Filling problems are not always caused by a stiff heart. For example, in atrial fibrillation (an abnormal heart rhythm more common with aging), the atria beat rapidly and irregularly. As a result, the atria do not move enough blood into the ventricles. If atrial fibrillation occurs suddenly in older people, heart failure may result.

Pumping problems

Pumping problems usually occur when the heart muscle has been damaged. A damaged heart pumps less blood, causing pressure inside the heart to increase and the heart's chambers to enlarge.

The most common cause of heart damage in older people is a heart attack (due to a blockage in an artery that supplies the heart with blood).

Heart valve disorders can also cause pumping problems.

In aortic stenosis (a heart valve disorder), the opening between the left ventricle and the aorta (aortic valve) narrows. As a result, pumping blood out of the heart is harder. Aortic stenosis is a common cause of heart failure in older people.

If a lung disorder such as COPD (chronic obstructive pulmonary disease) or scarring (pulmonary fibrosis) has been present for a long time, blood pressure in the lungs increases. As a result, it is harder for the right ventricle to pump blood to the lungs.