Heart Disease

hink of a heart attack victim and you'll probably picture a middle-aged man, perhaps a little paunchy, most likely a workaholic executive type. It's a stereotype that has been reinforced by the media and by the medical profession itself, which in the past has focused much of its research into heart disease on this type of patient.

Not Just a Man's Disease

The facts, however, tell quite a different story. Heart disease is more than just a man's disease—much more. One in 9 women between the ages of 45 and 64 has some form of cardiovascular disease, ranging from coronary artery disease to stroke or renal vascular disease. By the time a woman reaches 65, she has a 1 in 3 chance of developing cardiovascular disease. And a number of studies show that African­American women are at even greater risk than these averages.

Heart disease, in its various forms, is the leading killer of American women. The following statistics paint a graphic picture:

• One-third of all deaths of American women each year are attributable to heart disease. Heart disease kills more women each year than cancer, accidents, and diabetes combined.
• All forms of cardiovascular disease kill nearly 500,000 American women a year. Stroke alone kills 88,000.
• Myocardial infarction, commonly known as a heart attack, kills 244,000 women a year.
• Forty percent of women with heart disease will eventually die of it.

The reason that so much more attention has been focused on men is that they are much more likely to be stricken with heart disease in their prime middle years, whereas women tend to get it 10 to 20 years later. For most women, it is only after menopause that heart disease becomes a problem. But a woman of 60 is about as likely to get heart disease as a man of 50, and by time they are in their 70s, men and women get heart disease at equal rates.

CARDIOVASCULAR DISEASE: THE FATE OF EVERY THIRD WOMAN

Incidence of cardiovascular disease in selected age groups, by gender; Source: American Heart Association

The significance of these facts is clear when you consider the aging of the American population. By the year 2000, 38 percent of American women will be 45 years of age or older. By 2015, that percentage will rise to 45 percent. This means that heart disease in women will be an even bigger problem in the future than it is now.

Until now, treatment of women with heart disease has been based primarily on what is known about men. Given the many factors unique to a woman's health, this is not satisfactory. Treatment cannot adequately take account of these factors until they have been systematically studied and evaluated.

Until that happens, it is likely that women will continue to pay with delayed diagnosis, inadequate treatment, and a toll that can be counted in disabilities and deaths. In fact, some studies have shown that despite the fact that women with heart disease are often sicker than men with the same disease, they are frequently treated less aggressively.

The good news is that things are changing. Greater attention to women's health in general and a growing awareness of the risks of heart disease in women are replacing the disregard of the past. An increasing number of scientific studies are focusing on how heart disease affects women. Gradually, doctors are becoming better informed about the dangers to women from heart disease, so that they are less likely to attribute chest pain to anxiety or other non-heart-related problems. And women themselves are learning that their own attention to their health must not be limited to an annual visit to the gynecologist.

So why is this important? If nothing could be done about heart disease, all of this attention might be academic. However, heart disease is both preventable and treatable; and as doctors learn more about what causes the problem, it is becoming increasingly apparent that there is much that you can do to prevent it from ever occurring. Diet and lifestyle changes can be very effective preventive efforts for some forms of heart disease. To work best, these efforts should begin early in life, long before you perceive yourself to be at risk. And if heart disease does strike, modern science and technology have an ever­ growing arsenal of weapons available to successfully fight it and restore its victims to healthy and productive lives.

Statistics reflect an encouraging trend. Better understanding of preventative measures and increasing sophistication in diagnosis and treatment have resulted in decreasing rates of heart disease in both men and women. For example, in the 1980s, death rates from heart disease went down 27 percent for white women and 22 percent for African­American women.

Inside the Circulatory System

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When we talk about heart disease we are talking about not just disorders of the heart itself but of a variety of conditions that affect the body's circulatory system. To understand heart disease, and the confusing jargon that describes it—cardiovascular disease, coronary artery disease, myocardial infarction, heart failure, and so on—it helps to have some knowledge of the basic components of this system, and how they work.

A quick lesson in anatomy can help. The heart is the central organ of the circulatory system, a muscular pump a little larger than your fist that continuously forces blood through the lungs, where it takes on oxygen, and then through the arteries, capillaries, and veins that make up the rest of the circulatory system. The expansion and contraction of the heart as it sends blood through the body is your heartbeat. To get an idea of what a tireless workhorse the heart is, consider this: the average heart beats about 100,000 times every day, pumping about 2,000 gallons of blood.

The heart is made up primarily of muscle tissue, called myocardium, and is divided vertically by the septum. It consists of four chambers: two atria in the upper half and two ventricles in the lower half. The pumping of blood through the chambers is aided by four valves that open and close, allowing blood to flow through the heart in only one direction when it contracts. The four heart valves are:

• The tricuspid valve, located between the right atrium and the right ventricle.
• The pulmonary or pulmonic valve, between the right ventricle and the pulmonary artery leading to the lungs.
• The mitral valve, between the left atrium and the left ventricle.
• The aortic valve, between the left ventricle and the aorta, the main artery from the heart to the rest of the body.

It is important to be familiar with these valves because women are more likely than men to have valvular disease, particularly mitral valve prolapse, which is discussed in greater detail below.

The healthy heart operates in a highly organized fashion, triggered by electrical signals. Oxygen-depleted blood comes into the right atrium through the superior and inferior vena cava, the body's largest veins. It is pumped into the right ventricle, then into the pulmonary artery and on into the lungs, where it receives fresh oxygen. Oxygenated blood, a brighter red in color than before, flows back to the heart, entering the left atrium, then moving into the left ventricle, and finally pushing through the aorta into the network of arteries that branches out through the body. The first two arteries that branch from the aorta are the major coronary arteries, which supply blood to the heart muscle itself, enabling it to continue pumping.

THE GEOGRAPHY OF THE HEART

Surprisingly small given its importance, the heart is a fist-sized mass of muscle that pumps blood first through the lungs to pick up oxygen, then on through the rest of the body to deliver that oxygen to the body's cells. The heart lies at the center of an elaborate circulatory system that branches out in an intricate network of ever smaller vessels, ending in microscopic capillaries throughout all the body's tissues. The arteries, which conduct blood out from the heart, give the circulation an added boost, expanding with every heartbeat and contracting while the heart is at rest. The veins, which return blood to the heart, are equipped with a series of valves designed to keep the blood from flowing backward as it finishes its round trip through the system. Of all the vessels in the body, the coronary arteries are the most important, for it is their job to supply life-sustaining oxygen to the heart muscle itself.

The veins, arteries, and tiny capillaries that connect them are the blood vessels that make up the vascular system. These blood vessels are more than just tubes through which the blood flows as it circulates throughout the body. The muscular walls of the arteries act as mini­ pumps themselves, expanding with every heartbeat to help push the blood along, while veins are equipped with a type of one­ way valve, to prevent blood from flowing backwards.

As is the case with many illnesses, heart disease in women can be complicated by other factors. The two most important are diabetes and pregnancy.

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