Aging changes in the heart and blood vessels

Blood vessels

• The main artery from the heart (aorta) becomes thicker, stiffer, and less flexible. This is probably related to changes in the connective tissue of the blood vessel wall. This makes the blood pressure higher and makes the heart work harder, which may lead to hypertrophy (thickening of the heart muscle). The other arteries also thicken and stiffen. In general, most elderly people experience a moderate increase in blood pressure.
• Receptors, called baroreceptors, monitor the blood pressure and make changes to help maintain a fairly constant blood pressure when a person changes positions or activities. The baroreceptors become less sensitive with aging. This may explain the relatively common finding of orthostatic hypotension, a condition in which the blood pressure falls when a person goes from lying or sitting to standing, resulting in dizziness.
• The wall of the capillaries thickens slightly. This may cause a slightly slower rate of exchange of nutrients and wastes.

Blood

• The blood itself changes slightly with age. Aging causes a normal reduction in total body water. As part of this, there is less fluid in the bloodstream, so blood volume decreases.
• The number of red blood cells (and correspondingly, the hemoglobin and hematocrit levels) are reduced. This contributes to fatigue. Most of the white blood cells stay at the same levels, although certain white blood cells important to immunity (lymphocytes) decrease in number and ability to fight off bacteria. This reduces the ability to resist infection.

EFFECT OF CHANGES

Under normal circumstances, the heart continues to adequately supply all parts of the body. However, an aging heart may be slightly less able to tolerate increased workloads, because changes reduce this extra pumping ability (reserve heart function).

Some of the things that can increase heart workload include illness, infections, emotional stress, injuries, extreme physical exertion, and certain medications.

COMMON PROBLEMS

• Heart and blood vessel diseases are fairly common in older people. Common disorders include high blood pressure and orthostatic hypotension.
• Arteriosclerosis (hardening of the arteries) is very common. Fatty plaque deposits inside the blood vessels cause it to narrow and can totally block blood vessels.
• Coronary artery disease is fairly common.
• Angina (chest pain caused by temporarily reduced blood flow to the heart muscle), shortness of breath with exertion and heart attack can result from coronary artery disease.
• Abnormal heart rhythms (arrhythmias) of various types can occur.
• Heart failure is also very common in the elderly. In people older than 75, heart failure occurs 10 times more often than in younger adults.
• Valve diseases are fairly common. Aortic stenosis, or narrowing of the aortic valve, is the most common valve disease in the elderly.
• Anemia may occur, possibly related to malnutrition, chronic infections, blood loss from the gastrointestinal tract, or as a complication of other diseases or medications.
• Transient ischemic attacks (TIA) or strokes can occur if blood flow to the brain is disrupted.