Coronary heart disease affects 12 million Americans. Though it is one of the most serious diseases in the nation, there are many ways to understand and treat it. Author Barry Cohen, M.D., a cardiologist who has treated thousands of patients, addresses all of the most pressing questions, including: What causes coronary heart disease? How does cholesterol affect your heart? What medical tests will you need? What are the newest diagnostic tests available? What medications are prescribed? What is involved with an angioplasty and bypass surgery? What lifestyles changes will improve your health? What are the warning signs of a heart attack? Stay healthier by becoming an informed patient.
|Edition description:||Third edition|
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About the Author
Barry Cohen, M.D., is the medical director of the Cardiac Catherization Laboratory and co-director of the Valve and Structural Heart Program at the Morristown Medical Center’s Gagnon Cardiovascular Institute in New Jersey. He is a practicing clinical cardiologist with the Atlantic Medical Group’s Associates in Cardiovascular Disease in Springfield, New Jersey.
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Coronary Heart Disease: An Overview
When a doctor tells you that you have coronary heart disease, it can be worrisome and confusing. You undoubtedly have questions: What is coronary heart disease? Why did I get it? Do I need medication? Will I need surgery? Do I need to change my lifestyle? Hopefully, this book will answer these questions and many more.
What Is Coronary Heart Disease?
Coronary heart disease (CHD), also called ischemic heart disease, is a form of heart disease that's caused by narrowing of the coronary arteries that feed the heart. If you or someone you love has been diagnosed with CHD, it may help to know that you are not alone.
How Many People Have CHD?
CHD is the most common form of heart disease, affecting at least 16 million Americans. It is the single largest killer of both men and women in the United States, responsible for nearly a half million deaths each year, or about one out of every five deaths. CHD causes the vast majority of heart attacks (myocardial infarctions). Every forty seconds, someone in the United States suffers a coronary event, and every minute one of us will die from one. The American Heart Association estimates that this year alone, more than a million Americans will suffer from a new or recurring coronary event, and nearly 40 percent of those will die from it.
Coronary heart disease isn't just an American problem. It is also very common in Europe and other Westernized countries. Diseases of the heart and circulation, such as heart attacks and strokes, kill more people worldwide than any other cause. The World Health Organization estimates that as many as 30 percent of all deaths worldwide are caused by heart and circulation diseases such as CHD.
There is much you can do to reduce your risk of having a heart attack or dying from CHD. Sometimes just changing your lifestyle — following a heart-healthy diet, exercising regularly, and reducing the stress in your life — can prevent a heart attack or even reverse the narrowing in your arteries.
There are a number of medications — and new ones being developed every day — that can help lower your heart attack risk. Surgical procedures to open blocked arteries, or bypass surgery, can help compensate for blockages in your arteries and help keep your heart supplied with the blood it needs.
By educating yourself about treatment options with books such as this one and by working closely with your doctor, you can choose the treatments that will best enable you to live a long and healthy life.
The Circulatory System
The first step in taking charge of your CHD is to learn all you can about the disease. To understand what CHD is and how it affects your heart, you need to understand a little about your heart and how it works.
The circulatory system is made up of the heart, the lungs, and blood vessels called arteries and veins. This system carries blood, food, and oxygen to every cell in the body. It also carries waste products away from the cells and out of the body. Arteries carry blood enriched with oxygen and nutrients away from the heart to the cells in the body. Veins carry blood loaded with waste products from the cells back to the heart.
Between the blood vessels, capillaries — thinner than a strand of hair — connect the smallest arteries with the smallest veins. The walls of these tiny capillaries allow waste products from the cells to pass into the capillaries. This enables the blood to carry waste from the cells to be removed by the kidneys, liver, and lungs.
The Heart: An Amazing Pump
The heart is the pump that keeps the blood flowing around and around in an endless circle throughout the body. The heart is a hollow muscle that weighs less than a pound and is about the size of a man's fist. Despite its small size, this amazing organ beats an average of 100,000 times a day, pumping about 2,000 gallons of blood every day. By the time you are age seventy, your heart will have beaten more than 2.5 billion times.
Located in the center of the chest and protected by the breastbone and rib cage, the heart is actually a double pump that's divided into two upper chambers and two lower ones. A wall of tissue separates the left and right sides of the heart. The top chambers (atria) and lower chambers (ventricles) are connected by valves that act like one-way doors. These valves make sure blood flows only in one direction. In the heart, the blood is pumped from the left and right atria to the left and right ventricles. The right side of the heart sends blood to the lungs. The left side of the heart pumps blood out to the cells in the body.
Just like other muscles in the body, the heart needs its own supply of blood and oxygen to work properly. Even though the heart pumps blood through its chambers, the heart itself receives little nourishment from this blood. A separate set of arteries that branch off the aorta (the main artery that receives blood from the left ventricle) provide the heart's blood supply. These are called coronary arteries. The coronary arteries encircle the top and sides of the heart, bringing it oxygen-rich blood. The two major coronary arteries are the left coronary artery and the right coronary artery. These vessels divide into many smaller coronary arteries that feed the heart.
What Causes Coronary Heart Disease?
The walls of the arteries that provide blood to the heart have a smooth, flexible surface. However, over many years, these walls can become progressively irritated and damaged. The damage may result from substances such as fats, cholesterol, calcium, cellular debris, and platelets — the tiny cells responsible for blood clotting. When the artery walls become damaged, these substances can stick to them; coronary heart disease occurs when the arteries become narrowed and clogged.
Buildup of Plaque
This buildup of substances inside the artery walls is a process called atherosclerosis, which produces a substance known as plaque. As it accumulates, plaque acts a lot like the dirt and minerals that build up inside your home's plumbing. As the buildup becomes thicker, the flow through the pipes becomes clogged and may eventually stop.
Similarly, when your heart doesn't get enough oxygen, due to narrowed arteries, you may feel chest pressure or pain called angina. If the blood supply to part of the heart is completely cut off, the result is often a heart attack.
Everyone has a certain amount of atherosclerosis as they age. For many of us, atherosclerosis begins in childhood. Some people have a rapid increase in the buildup of atherosclerotic plaque after age thirty. For others, plaque buildup doesn't become a problem until they're in their fifties or sixties. You may hear the word arteriosclerosis being used interchangeably with atherosclerosis. The difference in the two words is technical. Arteriosclerosis refers to hardening of the arteries.
Why Atherosclerosis Develops
It's not fully understood why atherosclerosis occurs, but there are several theories. Some medical experts believe that the atherosclerotic buildup in the inner layers of the arteries may be caused by several conditions, including:
elevated levels of LDL cholesterol (low-density lipoprotein) and triglycerides (a type of blood fat in the blood)
low levels of HDL cholesterol (high-density lipoprotein)
high blood pressure
high blood sugar levels (diabetes)
inflammation in the artery walls
It's likely that more than one process is involved in the buildup of plaque. Many researchers believe that when excess fats combine, they become trapped in the artery walls. Then, any injury to the artery wall, such as damage caused by smoking, can cause more damage. Plaque grows, causing narrowing of arteries or causing blood clots to form. Advanced plaque consists of cell debris, calcium, smooth muscle cells, fatty deposits, connective tissue, and foam cells, which are white blood cells that have digested fat.
Cells containing plaque can be easily damaged. This can lead to blood clots forming on the outside of the plaque. Small clots can further damage other layers of the blood vessel wall and stimulate more plaque growth. Larger blood clots can partially or totally block the artery.
In addition to blocking blood flow, plaque can hinder the arteries' ability to dilate and contract. In order to respond to the body's ever-changing need for blood, the arteries need to be strong and elastic. For instance, when you exercise, your body needs more blood. The heart responds by pumping faster, and the arteries respond by expanding to accommodate the increased volume of blood coming from the heart. As the artery becomes narrowed and hard, that elasticity is lost. Arteries that have atherosclerotic plaque are more apt to spasm (temporarily narrow), causing even less blood to flow to the heart and possibly causing chest pain or a heart attack.
Inflammation and High Blood Pressure
Other conditions that may also damage the arteries include inflammation and high blood pressure. Inflammation refers to the body's natural defense to foreign invaders such as bacteria, toxins, or viruses. The tissues become inflamed.
High blood pressure occurs when the pressure of blood flowing through arteries is too high. Arteries are strong and elastic, enabling them to withstand pressure as the heart pumps; however, when blood pressure is too high, there is a chance that the extra pressure could weaken an artery. And, if your arteries are narrowed, there is a greater risk that they could become blocked. High blood pressure can lead to a heart attack, stroke, and other heart ailments.
Metabolic Syndrome and CHD
One of the conditions associated with the development of coronary heart disease is metabolic syndrome. Not an actual disease itself, metabolic syndrome is a cluster of disorders. According to current guidelines from the American Heart Association and the National Cholesterol Education Program, you have metabolic syndrome if you have three or more of the following conditions:
high-fasting blood sugar levels (insulin resistance)
high blood pressure
low HDL cholesterol
abdominal obesity — a waist circumference of forty inches or more in men, thirty-five inches or more in women.
Each of these disorders is associated with cardiovascular disease, stroke, and diabetes and the collective effect of metabolic syndrome significantly increases the risk of death from these diseases. One study reports that those with metabolic syndrome are 3.5 times more likely to die of a heart-related problem and 5 times as likely to develop type 2 diabetes.
High Blood Sugars
The core disorder of metabolic syndrome is insulin resistance, which explains why the condition is sometimes referred to as insulin resistance syndrome. Insulin is a hormone that controls the amount of sugar (glucose) in your bloodstream. When your body doesn't make enough insulin or use insulin efficiently, the result is higher levels of glucose in your blood. The high blood sugars increase the risk for CHD. The high glucose levels can damage blood vessels and nerves that control the heart. Individuals with diabetes tend to develop heart disease at a younger age.
How Common Is Metabolic Syndrome?
Metabolic syndrome is becoming increasingly common. It's estimated that 34 percent of the American population has metabolic syndrome; 85 percent with type 2 diabetes have it. Two other key actors that cause metabolic syndrome — obesity and physical inactivity — are related to lifestyle. Other factors include aging, genetic predisposition, hormonal imbalance, and a history of diabetes.CHAPTER 2
Risk Factors for Coronary Heart Disease
Perhaps you've wondered why you developed coronary heart disease. It's not fully known why some people develop CHD while others do not. We do know that certain factors — traits or lifestyle habits — increase your chance of having a heart attack or stroke. The more risk factors you have, the higher the likelihood that you'll have a buildup of atherosclerotic plaque. That's why it's important to understand and control the risk factors for CHD.
According to the National Heart, Lung, and Blood Institute of the National Institutes of Health, having multiple risk factors for CHD doesn't just add to your risk, it multiplies it. If, for instance, you're a smoker who has high blood pressure and high blood cholesterol, your risk for CHD is eight times greater than someone with no risk factors.
Most risk factors for CHD can be changed. Others, such as increasing age, family history, your race or gender, obviously, cannot.
Risk Factors You Can't Control
The older you are, the greater your risk for CHD, heart attack, and stroke. Four out of five people who die from CHD are sixty-five or older. If you're a man forty-five years or older, you're at increased risk for heart attack or stroke. If you're a woman fifty-five years or older, or you're past menopause, or you have had your ovaries removed at a young age, you are at increased risk.
The aging process itself is partly to blame. As we age, the connective tissues in our artery walls naturally become less flexible. As mentioned earlier, this is called arteriosclerosis, or "hardening of the arteries." This loss of flexibility in the arteries can cause blood pressure to increase, which can damage arteries and lead to the buildup of plaque. Rising blood pressure and hardened arteries can also make the heart work harder, which can cause the heart muscle to thicken and stiffen. When this occurs, the heart cannot function efficiently.
Family History of Heart Disease
If members of your family suffered from heart disease, you have a greater risk for CHD, heart attack, and stroke. You have even greater risk if your father or brother had a heart attack before age fifty-five or if your mother or sister had one before age sixty-five. You're also at increased risk if you have a relative who had a stroke.
Some people inherit genes that make them susceptible to the underlying causes of CHD such as diabetes, obesity, high blood cholesterol, or high blood pressure. For instance, diabetes or high blood pressure tends to run in some families. Other people may inherit risk factors such as familial hypercholesterolemia, a genetic disorder that causes excessively high LDL or "bad" blood cholesterol. For others, family lifestyle factors such as smoking, overeating, eating high-fat or processed foods, and not exercising may contribute to increased risk.
If you already have CHD, you're at increased risk for heart attack or stroke. If you've already had a heart attack or stroke, you are at risk for having a second one.
Some ethnic groups are at greater risk for CHD, heart attacks, and stroke. African Americans have higher rates of high blood pressure, a major risk factor for CHD. Mexican Americans, Native Americans, native Hawaiians, and some Asian Americans also have a higher risk for heart disease. Heart experts suspect higher risk among people in these groups may be related, in part, to their increased rates of obesity, diabetes, and smoking. Being economically disadvantaged or lacking access to good health care may also play a part in higher rates of heart disease and poorer prognosis among some groups.
In Japan, the incidence of CHD is lower than in Western countries, yet when Japanese immigrate to North America, their CHD risk climbs, though not as high as other Americans. This suggests that genetics, race, and environment all play a role in CHD.
Men have a greater chance of having a heart attack and having one earlier than women. Although this may be due to hormonal differences between men and women, men's rate of heart disease is greater even when compared to postmenopausal women who have lost their gender protection against heart attack.
Risk Factors You Can Control
High Blood Cholesterol
Cholesterol is a waxy, fatlike substance that's found in every cell in the body. It's a necessary substance that helps digest fats, strengthens cell linings, and makes up part of some types of hormones and vitamins. However, too much cholesterol can be bad for you, causing artery-clogging plaque.
Having high blood cholesterol is one of the most important risk factors for CHD and subsequent heart attacks and strokes. However, risk depends on the type of cholesterol you have. The higher your level of LDL cholesterol (low-density lipoprotein) — "bad" cholesterol — the greater your risk. When you have too much LDL cholesterol in your blood, the excess builds up on the walls of the coronary arteries. The opposite is true for "good" cholesterol, HDL cholesterol (high-density lipoprotein): having high HDL cholesterol protects against CHD; having low HDL cholesterol is a CHD risk factor.(Continues…)
Excerpted from "Coronary Heart Disease"
Copyright © 2019 Barry M. Cohen, M.D..
Excerpted by permission of Addicus Books, Inc..
All rights reserved. No part of this excerpt may be reproduced or reprinted without permission in writing from the publisher.
Excerpts are provided by Dial-A-Book Inc. solely for the personal use of visitors to this web site.
Table of Contents
1 Coronary Heart Disease: An Overview 1
2 Risk Factors for Coronary Heart Disease 11
3 Understanding Cholesterol 22
4 Symptoms of Coronary Heart Disease 29
5 Understanding Heart Attack 34
6 Heart Disease in Women 41
7 Getting a Diagnosis 46
8 Medications for Coronary Heart Disease 70
9 Stents and Bypass Surgery 81
10 Making Lifestyle Changes 98
About the Author 145