Introduction to Heart Disease
Your heart is one of your body's most important organs. Essentially a pump, the heart is a muscle made up of four chambers separated by valves and divided into two halves. Each half contains one chamber called an atrium and one called a ventricle. The atria (plural for atrium) collect blood, and the ventricles contract to push blood out of the heart. The right half of the heart pumps oxygen-poor blood (blood that has a low amount of oxygen) to the lungs where blood cells can obtain more oxygen. Then, the newly oxygenated blood travels from the lungs into the left atrium and the left ventricle. The left ventricle pumps the newly oxygen-rich blood to the organs and tissues of the body. This oxygen provides your body with energy and is essential to keep your body healthy.
The general term used to cover malfunctions of the heart is Heart Disease, or sometimes Cardiac Disease ("Cardiac" is a Latin term for the heart). Though there are multiple forms of heart disease, our discussion focuses on the two most common: Heart Attack and Heart Failure. This document is designed to teach you about heart attacks and heart failure: what causes these diseases, what forms these diseases take, and what can be done to treat these diseases when they occur. As both of these diseases are to some extent avoidable, we have also provided a discussion of preventative steps you can take to decrease your chances of having to deal with heart disease, or to minimize the negative effects of existing heart disease.
Please note that though this information is as accurate as possible, it is no substitute for a qualified physician's advice. Consult with your doctor before making changes to any treatment regimen you may be prescribed, and before beginning any program of exercise or other significant lifestyle change, especially if you have a known heart problem or are a middle-aged or older adult. There is no substitute for your doctor's advice.
Although heart disease can occur in different forms, there is a common set of core risk factors that influence whether someone will ultimately be at risk for heart disease or not. We start our discussion of heart disease by describing these common risk factors, and then move on to cover specific conditions.
There are many factors that can increase your risk of getting heart disease. Some of these factors are out of your control, but many of them can be avoided by choosing to live a healthy lifestyle. Some of the risk factors you cannot control are:
Gender: Men have a greater risk than women for developing heart disease. Men also are at greater risk of having a heart attack at a younger age. Unfortunately, these facts often mislead women into believing that they are not at risk for heart disease. This is not true; heart disease is the number one killer of women (just like men). Women and men should both take steps to prevent heart disease.
Age: Simply put, the older you get, the greater risk you run for developing heart disease. It is estimated that four out of five individuals who die of coronary heart disease are 65 years of age or older. Further, at older ages women are much more likely to have a fatal heart attack than men.
Family History: A family history of heart disease, high blood pressure (hypertension), and diabetes increases the chance you will develop heart disease. People with biological relatives who have heart attacks at a young age (i.e., less than fifty-five years old) are considered to have a "strong" family history of heart disease and are at much higher individual risk.
A person's family history of heart disease risk factors may also be affected by their ethnic background. For example, African Americans have a higher rate of hypertension. Since having uncontrolled high blood pressure increases an individual's chance of developing heart disease, African Americans tend to have a higher risk of developing heart disease. While your family background is not a certain indication that you will get heart disease, it can greatly increase your chances.
Fortunately, there are many other risk factors for heart disease that can be addressed by lifestyle habits and regular preventative medical care. Some of the more controllable risk factors include:
Obesity: People who are overweight are more likely to have high blood pressure, which increases the heart's overall workload. They also tend to have high cholesterol levels, which increases the chances of developing a blockage in blood flow to the heart. Furthermore, obesity increases a person's chance of developing diabetes, another major risk factor for heart disease. Getting regular exercise and eating a healthy diet are some of the best ways to control obesity and associated medical complications. Any complications caused by obesity should be evaluated and treated by your physician.
High Cholesterol: Cholesterol, a type of fat molecule, is an essential part of healthy cell membranes, and as such, is an essential part of a healthy body. Too much cholesterol in your blood, however, puts you at increased risk of heart disease. High levels of cholesterol and other fatty substances can cause atherosclerosis, a disease in which fatty plaques build up on blood vessel walls, restrict blood flow to the heart and can ultimately cause a heart attack.
There are two different types of cholesterol: low density lipoprotein (LDL, the so-called "bad cholesterol") and high density lipoprotein (HDL, the "good" cholesterol). High levels of LDLs increase your chance of having a heart attack. In contrast, the higher your HDLs, the more protection you have against heart attacks. Your cholesterol levels are determined by a combination of age, gender, heredity, dietary choices and exercise. LDL cholesterol can be decreased through exercise and dietary changes such as avoiding saturated and trans fats. The best way to raise your HDL cholesterol is through exercising.
If your cholesterol levels cannot be kept at a safe level (the optimal number depends on your age, family history, and medical history such as whether you have diabetes or a history of heart attacks) with diet and exercise changes, then you and your physician can consider a prescription for cholesterol-lowering medications. People with a history of diabetes or heart attacks need to keep their LDL cholesterol lower than individuals who do not have that history.
Smoking: Smoking is a major risk factor for heart attacks. Among other health consequences, smoking causes people's blood to clot more easily, and raises blood pressure, thereby putting their heart at risk. In terms of a heart disease prevention strategy, your best protection is to never start, or to quit smoking altogether if you already smoke.
High Blood Pressure: Uncontrolled blood pressure increases your risk of heart disease. The higher your blood pressure, the harder it is for your heart to pump blood throughout your body. Like any other stressed muscle, an overloaded heart responds to exertion by growing bigger; by thickening its walls and increasing it's overall size. While these changes sound positive, they actually are harmful and are signs of heart disease. As the walls of the heart thicken, the heart chamber's volume becomes greatly reduced and less blood can be pumped each time the heart beats. Also, the thickened muscle walls make it harder for the heart to pump out what blood it is able to collect. Exercise, a healthy diet and medication (if needed) can all help maintain a healthy blood pressure and therefore, a healthy heart.
Diabetes: As mentioned above, diabetes is a major risk factor for heart disease. A diabetic person's risk of developing heart disease is equivalent to the risk of a person who has had a previous heart attack. Diabetes is a disease of blood sugar regulation. People with diabetes are at greater risk for heart disease if their blood sugar is not kept under good control. In addition, diabetics also need to control their blood pressure and cholesterol levels. In fact, the cholesterol goal for a diabetic is as low as the goal for a person who has had a previous heart attack.
Other Factors: Stress, drinking too much alcohol, and depression have all been linked to cardiovascular disease. Stress may cause some individuals to overeat, smoke, and/or drink excessively. Drinking can lead to higher blood pressure and obesity. While some studies have suggested that daily moderate alcohol intake (one drink a day) can reduce the risk of heart disease, there is a balance. Alcohol can be an addictive drug, and it is a source of 'empty' (i.e., with limited nutritional value) calories. These extra calories can cause weight problems and diabetes, both of which are associated with heart risks of their own. Any decisions about alcohol consumption as it relates to your heart should be discussed with your doctor.