What is the one disease that women are most afraid of getting? Breast cancer. But just look at these statistics: approximately 44,000 women will die from breast cancer this year, and 500,000 will die of cardiovascular disease (heart attacks and strokes). Heart attacks alone kill 267,000 women each year, and cause six times as many deaths in women as breast cancer. Heart disease is the number one killer of men and women (AHA 2007). Surprised? Most women are.

Until recently, little was known about heart disease in women. Because our unpredictable hormone cycles got in the way, in the past, researchers studied only men and then applied their findings to women too. For years, science looked at women as “mini-men” who also had periods. Today, we know that women often experience quite different symptoms of heart disease than men do. We also know now that there are specific factors that contribute to the development of heart disease in men that may affect women differently, such as smoking cigarettes, diabetes, and lipid levels. It is important to understand all we can about these differences and how to prevent heart disease in the first place.

The Normal and Aging Heart

Let’s talk about the basics. First of all, what is the heart…really?

The Normal Heart

The heart is an organ made completely of muscle, roughly the size of your fist. In a lifetime, it can pump enough blood to fill three Olympic-sized swimming pools. If you have ever wondered whether a higher power existed, seeing a heart beating inside the chest would make you believe. This miraculous organ is linked to an intricate system of blood vessels, the arteries and veins, which together are known as the circulatory, or vascular, system.

The heart, the driving force of this system, is actually a two-sided pump. The right side of the heart pumps the “used” blood (without life-sustaining oxygen but with carbon dioxide, the body’s waste product) it receives from the body to the lungs. The left side of the heart receives the “fresh” blood (with oxygen but without carbon dioxide) from the lungs, and pumps it to the body and the blood vessels, including to the blood vessels that feed the heart, known as the coronary arteries. All this pumping of the heart, also known as “contracting” or “beating,” is done in an orderly and synchronized way, creating your pulse.

What keeps the heart beating? An electrical system, influenced by the brain and nerves, regulates the rate and rhythm of the contractions. When the electrical system becomes damaged, or doesn’t work properly, the contractions of the heart may become irregular, too fast, or too slow, or a contraction may be skipped; all of which will be experienced as an abnormal pulse. It’s important to know that an irregular pulse does not always mean there is a problem with your heart; some pulse rhythms or rates that are abnormal for others may be normal for you. That’s why it is imperative to learn what is normal for your body.

Because the heart is made up of muscle tissue, it needs to be treated just like any other muscle in your body; kept in shape in order to stay healthy so that it maintains a good, strong blood flow. When this blood flow is compromised, disease occurs. Compromise of the blood flow to the heart itself results in a heart attacks.

The Aging Heart

How an individual’s heart ages is as unique as she is, and depends on many factors including genetic risks for heart disease, and the sum total of her lifetime experiences and choices. Physical activity, body weight, diet, smoking history, presence of other diseases and how well they are managed, and stress levels are among the many factors that influence the aging of the heart. Therefore, from one person to another, there is much variability in how the heart ages.

Having said that, the heart and blood vessels, with no disease, do very well with aging. Some changes in this system related to aging include stiffening of the blood vessels which causes the systolic blood pressure (top number) to increase and the heart to pump harder. A decrease in the number of muscle cells causes the heart itself to stiffen; and, as in the aging brain, the death of some of its nerve cells results in changed electrical transmissions and a slowed, or irregular, heartbeat.

Despite these changes brought about by aging, the heart continues to function well in “normal” times. It is only when the heart is stressed, for instance, during a sudden emotional upset or when running or rushing up the stairs, that you may notice more difficulty than when you were younger; you may become short of breath or tire more quickly, or you may need to stop and catch your breath. However (and you can guess what’s coming next), if you’ve kept your heart muscle in shape with regular physical activity, both aerobic and strength training exercise, your heart will not show even the signs of aging when stressed. Yet another reason to exercise.

The Healthy Heart

For a healthy heart, you need healthy blood vessels, a healthy electrical system, and healthy heart muscle. Since diseases of the blood vessels and the electrical system are common in our age group—women over fifty—we’ll discuss how to keep these two components of the cardiovascular system healthy in this chapter.