Effects of Aging on the Cardiovascular System

Effects of Aging on the Cardiovascular System

The heart and blood vessels begin to develop during the third week of gestation, with the heart beginning to beat during the fourth week. The heart is the first embryonic organ to become functional. The foramen ovale permits blood flow from the right atrium to the left atrium while the lungs are developing, before birth. Development of the heart can become abnor-mal at any stage, though abnormalities occurring ear-lier in development are usually more severe. ­Septal defects are the most common heart abnormalities. During childhood, the most common cardiovascular disorders include congenital heart defects, viral infec-tions that affect the heart, and heart disease caused by illnesses or genetic syndromes. Congenital heart defects include heart valve disorders, hypoplastic left heart syndrome, and tetralogy of Fallot. Children who have diabetes or hypertension, or those who are obese, are more likely to develop atherosclerosis­ later in life. Other childhood cardiovascular disorders include arrhythmias, Kawasaki disease, heart murmurs, peri-carditis, and rheumatic heart disease.

Aging changes the heart and the blood vessels. The heart may experience a reduction in maximum output, changes to the nodal and conducting cells, reduction of elasticity of its fibers, progressive ath-erosclerosis that can restrict circulation through the heart, and the replacement of damaged cardiac mus-cle with scar tissue. Other age-related changes that affect the heart include valve thickening and stenosis and declines in cardiac reserve. Stiffening or stenosis of heart valves usually affects the mitral valve, result-ing in heart murmurs. An older heart is less able to respond to the need for increased cardiac output that is both sudden and prolonged. Maximum heart rate declines because sympathetic innervation becomes less efficient. Cardiac muscle cell death results in more fibrous tissue, stiffening the heart. It then fills less efficiently, and stroke volume is reduced. Fibrosis may also affect the nodes of the heart, which increases likelihood of arrhythmias and other conduction prob-lems. Atherosclerosis is intensified by stress, smoking, and inactivity. Serious results include coronary artery occlusion, hypertensive heart disease, heart attack, and stroke. Diet also contributes significantly to ath-erosclerosis. Physicians advise that Americans reduce their consumption of salt, cholesterol, and animal fat.