Heart disease is the leading cause of death in the U.S. At some point in your life, either you or one of your loved ones will be forced to make decisions about some aspect of heart disease. Knowing something about the anatomy and functioning of the heart, in particular how angina and heart attacks work, will enable you to make informed decisions about your health. Heart disease can strike suddenly and require you to make decisions quickly. Being informed prior to an emergency is a valuable asset to you and your family.

We will discuss various heart diseases and how they can lead to a heart attack, or even a stroke. We will also look at how heart attacks are treated and what you should do to prevent heart disease.

Coronary Artery Disease (CAD), Coronary Heart Disease (CHD), Ischemic Heart Disease (IHD), Arteriosclerotic Cardiovascular Disease (ASCVD), are all different names for the same disease. CAD is caused by atherosclerosis, which is a buildup of fatty deposits (atheroma) in the coronary arteries. See figure below:

Coronary arteries supply blood to the heart muscle. When a blockage occurs in one of these arteries, blood flow to the heart muscle is decreased. This becomes most evident during exertion. During exertion, the heart muscle is working harder and needs more oxygen enriched blood than usual. By preventing the much needed increase in blood flow, the blockage deprives the heart muscle of oxygen thereby causing the heart muscle to hurt. This chest pain is called angina or Angina Pectoris. When the heart muscle goes without sufficient oxygen, the muscle is said to be ischemic. If cell death occurs it is called infarction. Since a heart attack is cell death of heart muscle (myocardium) it is called a Myocardial Infarction (MI). The condition that causes CAD, angina and heart attacks is called atherosclerosis.

Atherosclerosis
Arteriosclerosis is a more general term for hardening of the arteries. Atherosclerosis is a type of arteriosclerosis that causes a buildup of fatty material (referred to as atheromas and plaques) along the inner lining of arteries. Depending on where these blockages occur, they can cause a number of different outcomes:

• If the blockage occurs in a coronary artery, it causes chest pain (angina).
• If the blockage is complete, it can cause a heart attack (Myocardial Infarction or MI).
• If the blockage occurs in one of the arteries near the brain, a stroke can occur.
• If a blockage occurs in a leg artery, it causes Peripheral Vascular Disease (PVD) and can cause pain while walking called intermittent claudication.

Atherosclerosis takes many years, even decades to develop and the condition can easily go unnoticed. Sometimes symptoms such as angina will gradually indicate the condition. However, it can also become evident in a sudden and severe way, in the form of a heart attack.

Let's take a look at some of the risk factors for atherosclerosis. Some of these factors are things you can control. By being proactive, you could reduce your risk.

Are You at Risk?
There are many risk factors that increase the likelihood of developing atherosclerosis and CAD. These include:

• hypertension (high blood pressure)
• diabetes
• elevated cholesterol
• smoking
• sedentary lifestyle
• stress
• obesity
• male sex
• family history of heart disease
• older age

Obviously, some of these risk factors can be changed or controlled (on your own or with the help of your physician) and some cannot. And, some of these risk factors have an effect on each other. For example, many people can lower their blood pressure by simply giving up smoking. Also losing weight can help:

• control blood sugar in diabetes
• lower blood pressure
• lower cholesterol

Age, Sex, Family history
You cannot control your age, family history, or gender. However, you can use these risk factors as impetous to take control of those risk factors you can change. Because heart disease is more common as we age, it is even more important to pay attention to your weight, blood sugar, cholesterol levels, blood pressure and exercise regimen. Men, in general, are at increased risk for coronary artery disease. When women reach menopause and the protective effect of the estrogen hormone is lost, the risk among genders becomes equalized. Keep in mind that while estrogen replacement may reduce a woman's risk of heart disease, there's a slightly increased risk of some cancers. Also, CAD is more common if you have a close relative (mother, father, sibling) who has had CAD at an early age.

Hypertension
Hypertension (elevated blood pressure) is a risk factor for CAD. Hypertension can also lead to strokes, kidney disease, and aneurysms. Also, hypertension causes the heart to work harder and can lead to Congestive Heart Failure. Your blood pressure (BP) has two numbers. In a blood pressure reading, the upper number is called the systolic blood pressure. A systolic BP less than 140 is considered normal. The lower number is called the diastolic BP. A diastolic BP less than 90 is considered normal. Blood pressure that is slightly higher than this is called mild hypertension and can sometimes be reduced by weight loss, cessation of smoking, and decreased salt intake. However, medications may sometimes be necessary.

Smoking
Smoking leads to CAD as well as many other illnesses such as COPD (chronic obstructive pulmonary disease which includes emphysema, asthma and chronic bronchitis). It also causes lung cancer, strokes and many other illnesses. Smoking may increase atherosclerosis as well. The nicotine in cigarettes causes constriction in blood vessels which causes an increase in blood pressure thereby causing the heart to work harder. Furthermore, nicotine may constrict coronary arteries and reduce blood flow to the heart muscle.

There are many ways to stop smoking. Usually it is best to quit completely either by yourself or with the help of support groups, along with the use of nicotine gum or a nicotine patch.

Elevated cholesterol
There is a definite relationship with elevated cholesterol and CAD. Cholesterol is transported in the blood by lipoproteins. Two of these lipoproteins are low density lipoprotein (LDL) and high density lipoprotein (HDL). An elevated level of LDL (the bad cholesterol) is associated with an increased risk of CAD. An elevated level of HDL (the good cholesterol) is associated with a decreased risk of CAD. Cholesterol levels can be lowered by eating a diet low in meat, eggs and dairy products. However, most of the cholesterol in the blood is produced in the liver. If a low fat diet does not sufficiently reduce your cholesterol, then your physician can prescribe medications to do so.

Obesity
Obesity is defined as being 20% over maximum desirable weight for your height. The Body Mass Index (BMI) is the most widely used formula for determining obesity: (weight/height²). A BMI of 20-25 is considered good, over 27 is considered overweight, and over 30 is considered obese. Obesity increases the risk of heart disease by increasing other risk factors such as high blood pressure, diabetes, and lowering HDL (good cholesterol).

Diabetes Mellitus
Diabetes Mellitus increases the risk of heart disease because it elevates cholesterol levels and increases atherosclerosis. Furthermore, people with diabetes are often overweight thereby exacerbating their diabetes and increasing the risk of heart disease. There are two types of Diabetes, Type I (insulin dependent) and Type II (non-insulin dependent). In Type I diabetes, very little or no insulin is produced by the pancreas so this condition is treated with insulin. In Type II diabetes, insulin is still being produced by the pancreas but the body is resistant to it. Type II diabetes can be treated by weight loss, a modified diet and an exercise regimen. If these methods are unsuccessful, medications called Oral Hypoglycemics are used. By increasing the secretion of insulin by the pancreas, these medications usually work. However, if these fail, insulin may be necessary.

Stress
High levels of stress and having what is known as a "Type A personality" may be risk factors for heart disease. Stress can cause your heart to work harder by increasing your blood pressure and pulse. Learning to calm down, slow down, and relax can help ease the effects of stress. It can also be beneficial to avoid caffeine and nicotine, and incorporate some type of exercise regimen into your daily routine.

Sedentary Lifestyle
Having a sedentary lifestyle leads to being overweight which can then lead to diabetes and elevated blood pressure -- both are risk factors for CAD. Exercise may lower LDL and increase HDL. It also strengthens the heart and increases its efficiency as well as the efficiency of the body's use of oxygen. People who exercise generally have a slower pulse and this puts less strain on the heart.