Heart and Arteries Health for Older Adults

by National Institute on Aging

Age is the major risk factor for cardiovascular disease. Heart disease and stroke incidence rises steeply after age 65, accounting for more than 40 percent of all deaths among people age 65 to 74 and almost 60 percent at age 85 and above. People age 65 and older are much more likely than younger people to suffer a heart attack, to have a stroke, or to develop coronary heart disease and high blood pressure leading to heart failure. Cardiovascular disease is also a major cause of disability, limiting the activity and eroding the quality of life of millions of older people each year. The cost of these diseases to the Nation is in the billions of dollars.

To understand why aging is so closely linked to cardiovascular disease, and ultimately to understand the causes and develop cures for this group of diseases, it is essential to understand what is happening in the heart and arteries during normal aging - aging in the absence of disease. This understanding has moved forward dramatically in the past 30 years. The purpose of this booklet is to tell the story of this progress, describe some of the most important findings, and give a sense of what may lie ahead.

While we know a great deal about cardiovascular disease and its risk factors, new areas of research are beginning to shed further light on the link between aging and the development and course of the disease. For instance, scientists at the National Institute on Aging (NIA) are paying special attention to certain age-related changes that occur in the arteries and their influence on cardiac function.Many of these changes, once considered a normal part of aging, may put people at increased risk for cardiovascular disease.

This and other compelling research on the aging heart and blood vessels takes place at many different research centers. A great deal of the work is being done by researchers in the Laboratory of Cardiovascular Science at the NIA or by NIA-funded scientists at other institutions. Others have worked at or been funded by the National Heart, Lung, and Blood Institute (NHLBI). NIA and NHLBI are two of 27 research institutes and centers at the National Institutes of Health, and their work is complementary. NIA research focuses on the effects of aging on the heart, blood vessels, and other parts of the body, while NHLBI works to understand the diseases and risk factors that affect the heart and blood vessels.

Both perspectives are bringing us closer to the possibility that heart disease and stroke will someday be defeated. Research on the basic biology of the aging cardiovascular system nurtures hope that we as a Nation need not accept the high rates of death and disability and the enormous health care costs imposed by cardiovascular disease among older people in our society.

Heart: A Host of Interconnections

"The heart is purest theater ... throbbing in its cage palpably as any nightingale."

Richard Selzer, M.D., American Surgeon and Author

It is scarcely as big as the palm of your hand yet it sustains life, pumping up to 5 quarts or more ofblood per minute to the body's organs, tissues, and cells. In a typical day, it beats 100,000 times. And in a lifetime, it beats more than 2.5 billion times. Even as you rest, your heart is working twice as hard as your leg muscles would if you were running at full speed.

Little wonder then that from earliest mythology to modern medicine, the heart has fascinated and perplexed us. Fortunately, today we know farmore about the heart and the blood vessels than was known even a decade ago. Yet for all scientists have learned, there is still much more to unravel. Investigators, for instance, now know that the cardiovascular system undergoes significant changes as we age, and the heart and arteries that we are born with are surprisingly different in later life.

But how and why do these changes occur? What influence do these changes have on our risk of developing heart disease and other cardiovascular disorders as we get older? Are there any underlying signs - even in people who appear to have healthy hearts - that precede and predict who will develop severe cardiovascular disease and who won't?

Scientists called gerontologists, who study aging, are seeking to answer these and other questions. As a result of this probing, some old ideas about the aging cardiovascular system are giving way to new theories. In other cases, gerontologists are just beginning to explore some questions, and the heart and arteries are yielding their secrets grudgingly.

But to truly understand what is emerging and what remains mysterious, we'll need to start where these gerontologists began: in the normal, healthy heart.

The Intricate Pump

The heart is a marvel of coordination and timing. Almost completely composed of muscle called myocardium, it is well-equipped for its life-long marathon of ceaseless beating. It is essentially two pumps in one. The right side pumps blood to the lungs to load up on oxygen and dispose of carbon dioxide. The left side pumps oxygen-rich blood to the body.

To accomplish these tasks, the heart depends on a precise sequence of contractions involving its two upper chambers - the right and left atria - and its two lower ones, the right and left ventricles. Between these chambers are two valves, each with two or three flaps, also known as cusps. The tricuspid valve separates the right atrium and the right ventricle. Its counterpart, separating the left atrium and the left ventricle, is called the mitral valve. The pulmonic valve controls blood flow out of the right ventricle to the lungs where it picks up oxygen. The aortic valve controls the flow of oxygenated blood out of the left ventricle into the body. Normally these valves let blood flow in just one direction.

About the Author

www.nia.nih.gov
NIA, one of the 27 Institutes and Centers of NIH, leads a broad scientific effort to understand the nature of aging and to extend the healthy, active years of life. In 1974, Congress granted authority to form NIA to provide leadership in aging research, training, health information dissemination, and other programs relevant to aging and older people.