Many different body organs must stay in good working order for you to enjoy good health. But one organ in particular—your heart—is primarily responsible for keeping all the others alive and well. Your heart circulates the blood that provides life-sustaining oxygen to your body’s tissues and removes carbon dioxide, the by-product of healthy cell activity. Cardiologists diagnose and treat cardiovascular diseases, by far the leading cause of death among Americans. 

How Your Heart Works

While the workings of the heart involve many intricate processes, the basic principle is very simple. Your heart is a muscle that acts as a pump. As it beats, rhythmically contracting and relaxing, it pumps blood infused with oxygen by your lungs to all parts of your body. After delivering the oxygen and picking up waste carbon dioxide, the blood then returns to the heart, which pumps it back into the lungs where the carbon dioxide is replaced with a new supply of oxygen. Without this continuous cycle, the tissues in your body would begin to die very soon.

The heart has four chambers. Blood from the lungs is drawn into the left atrium. It then flows through the mitral valve into the left ventricle. The most powerful part of your heart muscle, the left ventricle pumps blood through the aortic valve out to the rest of your body. When it returns, the blood enters the right atrium. Passing through the tricuspid valve, blood enters the right ventricle, which then pumps it through the pulmonary valve to the lungs. All this pumping action requires continuous muscle contractions triggered by small electrical impulses from nodes in the heart. The opening and closing of the heart valves coincide precisely with the contractions.

What Is Cardiovascular Disease?

It’s important to remember that one of the organs requiring a constant supply of nourishing blood is the heart itself. When oxygenated blood leaves the left ventricle, one of its first destinations is the coronary arteries within the heart muscle tissues. A common and dangerous form of cardiovascular disease occurs when one or more of the coronary arteries becomes clogged with fatty deposits, called plaque.  Decreased blood flow to the heart muscle can cause tissues to weaken and die. If enough tissue dies, the heart begins to fail, resulting in a heart attack.

Other types of heart disease involve faulty heart valves, malfunctions of the electrical conduction system, infection and inflammation of heart tissues, and problems with the structure of the heart or surrounding blood vessels.

What to Watch For

No single symptom indicates heart disease. Some of the common signs include pain or tightness around the chest, shortness of breath, fatigue, palpitations (unusual heart rhythms), and light-headedness or fainting. Unfortunately, though, heart disease may cause no symptoms at all until it becomes very serious. That’s why regular check-ups are essential.

For More Information

Select a link below for more information on commonly treated diseases and conditions.  For other conditions not listed visit our Health Encyclopedia.

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