Cardiovascular disease: A blueprint for understanding the leading killer

You’ve seen the stories time and again: Exercise to prevent coronary artery disease. Eat better to reduce your risk of coronary heart disease. Stop smoking to stop heart disease. Lower your cholesterol to lower your odds of developing cardiovascular disease.

Coronary artery disease? Coronary heart disease? Heart disease? Cardiovascular disease? What are all these things? And what’s the difference, anyway?

Perhaps you’ve been bombarded so often with warnings and advice about your heart that you simply don’t pay attention anymore. Or you don’t know what these conditions mean or exactly how destructive they can be to your health.

Understanding the various terms and how they’re often used — sometimes incorrectly — can help you sort through the morass. And if you know more about the various types of cardiovascular disease, and the havoc they can wreak on your body, you may be more inclined to take steps to prevent them. You’ll also know more about the ways all of the different manifestations of cardiovascular disease interact to affect your health, and you’ll learn how you can best control your risks.

Defining cardiovascular disease

First, consider cardiovascular disease. Cardiovascular disease is a broad, all-encompassing term. It’s not a single condition or disorder in itself. Rather, it’s a collection of diseases and conditions. In fact, some types of cardiovascular disease can even cause other types of cardiovascular disease.

To get technical, cardiovascular disease refers to any disorder in any of the various parts of your cardiovascular system, which is made up of your heart and the blood vessels throughout your body, explains Brooks Edwards, M.D., a cardiologist at Mayo Clinic, Rochester, Minn., and medical editor in chief of this site.

Cardiovascular disease, then, has two main components:

  • Diseases of the heart (cardio)
  • Diseases of the blood vessels (vascular)

Although you may hear a lot about preventing cardiovascular disease, sometimes you can’t prevent it. That’s because some types of cardiovascular disease are congenital — you’re born with them. Other forms are acquired — you develop them over the course of your lifetime. These acquired conditions are the forms you can often help prevent by doing such things as exercising regularly, eating a balanced diet or quitting smoking. And they make up the vast majority of cardiovascular diseases.

So, if you have something wrong with your heart, such as an abnormality of the heart muscle (cardiomyopathy), that’s a type of cardiovascular disease. Likewise, an aneurysm, a bulging section of blood vessel, also is a type of cardiovascular disease. And even varicose veins are technically classified as a cardiovascular disease.

But what about those news reports that say cardiovascular disease is the No. 1 killer of American men? What does that mean, really?

Are they getting aneurysms? Dying of varicose veins? Did they have a congenital heart defect that couldn’t be successfully treated? Just what do those reports mean? Adding to the confusion are the different ways that major organizations and agencies, including the Centers for Disease Control and Prevention and the American Heart Association, define cardiovascular disease.

It’s no wonder you’re left scratching your head. But to help sort through all of that and help you become a health-savvy consumer the next time you read one of those reports, here’s a closer look at just what cardiovascular disease is.

Diseases of the heart

The heart consists of a muscle (myocardium) that pumps blood, arteries that supply blood to the heart muscle, and valves to ensure that the blood is pumped in the correct direction. At any point in the pumping process, or in any part of the heart, something can go awry. The diseases and conditions affecting the heart are collectively known as heart disease.

Like cardiovascular disease, the term heart disease is somewhat loose and broad, and it’s often used that way. You may see reports urging you to avoid smoking so that you reduce your risk of heart disease, for instance. And you can. Or that heart disease is the leading killer of both men and women. And it is.

But neither exercise nor healthy diet nor low cholesterol can protect you against all forms of heart disease. There are many types of heart disease, and not all are the consequences of unhealthy lifestyle habits. Some forms of cardiomyopathy are caused by viruses, for instance. And some babies are born with Ebstein’s anomaly, a defect in one of the heart’s valves that causes blood to leak and prevents the heart from working at top efficiency.

Most often, when you hear a report about preventing heart disease, it’s really a call to prevent coronary artery disease or coronary heart disease.

Coronary artery disease. These are diseases of the arteries that supply the heart muscle with blood. Sometimes known as CAD, coronary artery disease is the most common form of heart disease in industrialized nations and far and away the leading cause of heart attacks.

Coronary artery disease generally means that blood flow through the arteries has become impaired. The most common way such obstructions develop is through a condition called atherosclerosis, a largely preventable type of vascular disease.

Coronary artery disease

The actively contracting heart muscle needs a steady supply of oxygen and nutrients to function. They’re delivered by blood vessels known as coronary arteries.

Over the course of your lifetime — actually starting in early childhood — these arteries, whose inner lining is normally smooth, can slowly become clogged with clumps of fats, cholesterol and other material, called atherosclerotic plaques. You may also know this as hardening or narrowing of the arteries. The inner walls of arteries become narrow slowly because of a buildup of these plaques, or suddenly by a rupture of a plaque and the formation of a blood clot around the ruptured plaque.

As a result, the supply of blood — with its oxygen and nutrients — going to the heart muscle is choked off (myocardial ischemia). As less blood reaches the heart, it can’t function normally, and you begin experiencing the physical consequences.

Chest pain (angina pectoris) occurs, for instance, when the oxygen demand of the heart muscle exceeds the oxygen supply because of that narrowing in the coronary arteries. When the imbalance of oxygen supply lasts for more then a few minutes, heart muscle can begin to die, causing a heart attack (myocardial infarction). This may occur without symptoms (silent heart attack), especially in people with diabetes.

In addition, the lack of blood, even briefly, can lead to serious disorders of the heart rhythm, known as arrhythmias or dysrhythmias. Coronary artery disease can even cause sudden death from an arrhythmia without any prior warning.

These consequences of coronary artery disease are also types of cardiovascular disease in their own right and, in turn, can cause even more types of cardiovascular disease — weaving a complex interplay of cause and effect. A heart attack, for instance, can lead to congestive heart failure, and both of these conditions are types of cardiovascular disease.

There’s another confusing twist to coronary artery disease: It’s sometimes used synonymously with coronary heart disease. But you can impress your cardiologist on the next visit — if not your colleagues around the water cooler — if you know they’re not technically the same things.

Rather, coronary heart disease is a more encompassing term that refers to diseases of the coronary arteries and their resulting complications — angina, a heart attack and even scar tissue caused by the heart attack. All are technically coronary heart diseases. Remember, coronary artery disease is disease only of the arteries.

Cardiomyopathy. These are diseases of the heart muscle. Some forms of cardiomyopathy are genetic, while others occur for reasons that are less well understood. The most common type of cardiomyopathy in developed nations is ischemic cardiomyopathy, which is caused by the loss of heart muscle from a heart attack resulting from coronary artery disease. Some forms of cardiomyopathy affect the contraction of the heart (systolic dysfunction) while other forms affect the filling, or relaxation, phase of the heart (diastolic dysfunction).

Valvular heart disease. These are diseases of the valves within the heart. Blood flows in the correct direction within the heart because of a series of valves. When a valve is diseased, blood flow may become obstructed, a condition known as valvular stenosis. Or a valve may leak, causing a condition known as valvular insufficiency or valvular regurgitation. You may be born with valvular disease, or the valves can become infected and damaged by bacteria or other microorganisms, a condition known as infectious endocarditis.

Heart valve defects

Pericardial disease. These are diseases of the sac (pericardium) that encases the heart. Diseases of the pericardial sac can secondarily affect the heart itself. There are several types of pericardial disease, including inflammation (pericarditis), fluid accumulation (pericardial effusion) and stiffness (constrictive pericarditis). These forms can occur alone or together. Causes and consequences vary. For instance, pericardial effusion can occur after a heart attack and, as a result, prevent your heart from working efficiently.

Pericardial disease

Congenital heart disease. These are forms of heart disease that develop before birth (congenital). Some may be apparent right at the time of birth, while others may not be detected until later in life. Congenital heart disease can affect the formation of the heart’s chambers, muscle or valves, and include such conditions as narrowing of a section of the aorta (coarctation) and Ebstein’s anomaly.

Congenital disorders

Congestive heart failure. Congestive heart failure occurs when the heart no longer pumps normally, although it does continue to work to some degree. With less effective pumping, vital organs don’t get enough blood, causing such signs and symptoms as shortness of breath, fluid retention and fatigue. This condition may develop suddenly or over many years. Congestive heart failure occurs as a result of other cardiovascular conditions that have damaged or weakened the heart. Among them are coronary artery disease, cardiomyopathy, valvular heart disease, and some forms of congenital heart disease.

Congestive heart failure

Diseases of the blood vessels

High blood pressure. High blood pressure (hypertension) is perhaps the most common form of cardiovascular disease in the Western world, affecting about one in four Americans. It’s also one of the most preventable and treatable types of cardiovascular disease.

But it’s more than just a type of cardiovascular disease. High blood pressure is also a cause of cardiovascular disease and a risk factor for cardiovascular disease.

Blood pressure is determined by how much blood your heart pumps out and how narrow your arteries are. The more your heart pumps and the narrower your arteries — say they’re clogged from atherosclerosis — the higher your blood pressure, and the harder your heart has to work to pump the same amount of blood.

High blood pressure

High blood pressure has far-reaching and serious health consequences. For one thing, it accelerates the development of atherosclerosis, which, in turn, makes high blood pressure worse and further increases the risk of other cardiovascular complications.

High blood pressure can also lead to stroke. That happens when a bit of cholesterol or other clump of arterial plaque breaks off and blocks blood flow to the brain. It may also happen when a tiny blood vessel in the brain ruptures because of damage sustained by high blood pressure. Stroke is sometimes considered a type of cardiovascular disease. But technically, it’s actually a result of cardiovascular disease.

In addition, high blood pressure can wreak havoc on the heart itself. It can cause coronary artery disease, congestive heart failure and heart attack. And the damage doesn’t stop there: High blood pressure can also damage other vital organs, such as your kidneys and eyes.

Aneurysms. An aneurysm is a bulge or weakness in the wall of an artery or vein. Aneurysms usually enlarge over time, and have the potential to rupture and cause life-threatening bleeding. Aneurysms can occur in arteries in any location in your body, but common sites include the abdominal aorta and the arteries at the base of the brain.

Aortic aneurysm

The vast majority of aneurysms occur when an artery wall becomes weak or damaged by atherosclerosis. And that means in many cases, aneurysms are another type of cardiovascular disease that’s preventable. The usual suspects in blood vessel damage are often to blame here, too — smoking, high blood pressure, and unhealthy lifestyle habits that contribute to atherosclerosis.

Brain aneurysms are a different matter and often result from a congenital weakness in the arteries at the base of the brain.

Claudication. Strictly speaking, this is a symptom of the condition occlusive arterial disease, but it’s often referred to as a disease itself. Symptoms develop when the arteries to the legs or arms become partially obstructed, compromising blood flow — similar to how coronary artery disease can cause angina. When the obstruction is mild, you may have such symptoms as extremity pain during strenuous exercise. As the disease progresses and arteries become more obstructed, you may notice symptoms with minimal or no activity at all and develop ulcers of the skin and soft tissue that don’t heal.

Walk this way: Managing the pain of intermittent claudication

As with aneurysms, claudication is most often caused by preventable atherosclerosis. Claudication isn’t just a type of cardiovascular disease. It’s also a symptom of other cardiovascular disease — the pain of claudication can be a symptom that you have atherosclerosis.

Vasculitis. This is inflammation of the blood vessels. It usually involves the arteries but may also affect small veins and capillaries. The inflammation may damage the wall of the artery or vein and impair blood flow to the region of the body supplied by that vessel. Sometimes vasculitis occurs in the presence of a generalized disorder, such as lupus or rheumatoid arthritis, but it sometimes occurs without an associated disease.

Vasculitis

Venous incompetence. This is a condition in which blood actually flows the wrong way in veins. Veins have tiny valves that are designed to promote blood flow in a forward direction, back to the heart. But if you have such conditions as infection, inflammation, abnormal blood clotting, or even high-back pressure in pregnancy, the valves may become damaged and incompetent. That allows blood to flow backward and pool in the extremities when sitting or standing, causing a variety of complications, such as prominent and painful varicose veins, skin changes and ulcers.

Venous thrombosis. This is the abnormal formation of a blood clot (thrombus) in a vein. This condition may damage the vein and its valves. In addition, clots that break off and travel in the bloodstream can lodge in the lungs, a condition known as pulmonary embolism. In some cases, this type of clot can also cause a stroke.

Varicose veins. This is a condition in which veins become gnarled, twisted and enlarged. They’re usually located on the backs of the calves or on the inside of the legs, from the groin to the ankle.

Varicose veins

When valves in your veins don’t function properly, blood can accumulate in your lower extremities, causing the veins to bulge and twist. The veins appear blue because they contain less oxygen.

Prevention power

“Cardiovascular disease is not a linear disease,” Dr. Edwards says. “People don’t usually have only one of these conditions that make up cardiovascular disease. Most of the time there’s a complex interplay of the conditions, and a primary disorder may cause a secondary disorder, which can lead to other disorders and make all of them worse, including the primary disorder.”

Furthermore, he notes, one cardiovascular disease can be a manifestation of another. Case in point: aneurysm. It can be a sign that you have atherosclerosis.

All of this underscores the complexity that is cardiovascular disease. But in the end, the most common forms of cardiovascular disease are high blood pressure and coronary artery disease, both of which are highly preventable.

Some preventive measures you can take:

  • Don’t smoke or use other tobacco products
  • Eat a varied diet, rich in fruits, vegetables and low-fat foods
  • Maintain a healthy weight
  • Get at least 30 minutes of exercise daily, most days of the week
  • Keep your cholesterol levels in normal ranges
  • Control your blood sugar if you have diabetes
  • Control your blood pressure
  • You have the power to greatly reduce your risk of cardiovascular disease, whether it’s heart disease, coronary artery disease or coronary heart disease — or any of their numerous incarnations.