Aging changes in the heart and blood vessels occur normally as a person gets older.
In a healthy individual without heart disease, the size of the heart stays the same or may increase slightly with age. As the heart muscle ages, the number of muscle cells gradually decreases. Fat and fibrous tissue is deposited into the heart muscle, causing it to become stiffer and the cells to degenerate slightly.
These changes reduce the strength of the heart and the amount of blood it can pump. In addition, the walls of the heart thicken, decreasing the amount of blood the chambers of the heart can hold. Less oxygen reaches the heart muscle because fewer branches of blood vessels lead to the heart.
The valves that control the blood flow through and out of the heart may gradually thicken and become more difficult to move with age, in part because of calcium deposits in the valves. The abnormal movement of a valve so affected can be heard through the stethoscope as a heart murmur.
The heart has a limited number of specialized cells at certain locations (nodes) in the heart muscle that are responsible for controlling the heart rate. When some of these cells die, the maximum rate that the heart can achieve on demand is reduced with age. When a heart has both a limited rate and a decreased pumping capacity, the end result is a reduced tolerance for exercise in elderly people.
Fibrous tissue and fat deposits also interfere with the natural electrical pathways that lead from the nodes to the rest of the heart muscle. These deposits rarely result in symptoms or illnesses in people without heart disease, although they cause certain changes in conduction that can be detected on an electrocardiogram (ECG).
As a person ages, the amount of blood the heart pumps over a period of time and the heart rate when the person is at rest usually do not change. However, after a period of stress, the heart rate and blood pressure may take longer to return to normal in an older person.
The arteries of the body naturally become less elastic ("stretchable") with age, leading to an increase in blood pressure because the heart has to work harder to push the blood through the arteries. (This change is different from blockage inside the arteries—atherosclerosis -- that leads to heart attacks and strokes.)
Other factors also increase blood pressure over time. Some of these include excessive salt in the diet, smoking, and overweight. Other factors are genetic and thus cannot be changed, and still others have no known explanation. When blood pressure is high for whatever reason, it needs to be treated so as to reduce a person's risk of heart attack and stroke.
The baroreceptor cells in the carotid arteries of the neck react to changes in activity level and body position by regulating the blood pressure. As a person ages, these cells become less responsive. Thus, when an older person stands up quickly from a sitting or lying position, the baroreceptors may be "caught napping" and the person may experience a quick drop in blood pressure.
The result for the person is lightheadedness, dizziness, or in extreme cases, loss of consciousness and a fall. The dizziness is decreased if a person sits up slowly and waits a few minutes before standing. There may also be a decrease in the amount of blood pumped to various organs of the body, including the brain and heart.
Older people experience many other heart and blood vessel problems that are not considered normal parts of the aging process. Blockage of the arteries, heart attacks, and strokes are common causes of illness and death in the elderly. These can often be prevented. Regular exercise can delay and even reverse many changes in the heart and blood vessels that occur with age.
A healthcare professional can provide information regarding a fitness or exercise program for the individual. Following a heart-healthy diet, reducing coronary risk factors, and seeking regular healthcare can reduce the risk of heart problems as a person ages.