Your heart is an amazing organ. It continuously pumps oxygen and nutrient-rich blood throughout your body to sustain life. This fist-sized powerhouse beats (expands and contracts) 100,000 times per day, pumping 5 or 6 quarts of blood each minute, or about 2,000 gallons per day.
Blood is essential. In addition to carrying fresh oxygen from the lungs and nutrients to your body's tissues, it also takes the body's waste products, including carbon dioxide, away from the tissues. This is necessary to sustain life and promote the health of all the body's tissues.
Looking at the outside of the heart, you can see that the heart is made of muscle. The strong muscular walls contract (squeeze), pumping blood to the arteries. The major blood vessels connected to your heart are the aorta, the superior vena cava, the inferior vena cava, the pulmonary artery (which takes oxygen-poor blood from the heart to the lungs where it is oxygenated), the pulmonary veins (which bring oxygen-rich blood from the lungs to the heart), and the coronary arteries (which supply blood to the heart muscle).
On the inside, the heart is a four-chambered, hollow organ. It is divided into the left and right side by a wall called the septum. The right and left sides of the heart are further divided into two top chambers called the atria, which receive blood from the veins, and two bottom chambers called ventricles, which pump blood into the arteries.
The atria and ventricles work together, contracting and relaxing to pump blood out of the heart. As blood leaves each chamber of the heart, it passes through a valve. There are four heart valves within the heart:
Each valve has a set of flaps, called leaflets or cusps. The mitral valve has two leaflets; the others have three. The leaflets are attached to and supported by a ring of tough, fibrous tissue called the annulus. The annulus helps to maintain the proper shape of the valve.
The leaflets of the mitral and tricuspid valves are also supported by tough, fibrous strings called chordae tendineae. These are similar to the strings supporting a parachute. They extend from the valve leaflets to small muscles, called papillary muscles, which are part of the inside walls of the ventricles.
Once blood travels through the pulmonic valve, it enters your lungs. This is called the pulmonary circulation. From your pulmonic valve, blood travels to the pulmonary artery to tiny capillary vessels in the lungs.
Here, oxygen travels from the tiny air sacs in the lungs, through the walls of the capillaries, into the blood. At the same time, carbon dioxide, a waste product of metabolism, passes from the blood into the air sacs. Carbon dioxide leaves the body when you exhale. Once the blood is purified and oxygenated, it travels back to the left atrium through the pulmonary veins.
Like all organs, your heart is made of tissue that requires a supply of oxygen and nutrients. Although its chambers are full of blood, the heart receives no nourishment from this blood. The heart receives its own supply of blood from a network of arteries, called the coronary arteries.
When the coronary arteries narrow to the point that blood flow to the heart muscle is limited (coronary artery disease), a network of tiny blood vessels in the heart that aren't usually open called collateral vessels may enlarge and become active. This allows blood to flow around the blocked artery to the heart muscle, protecting the heart tissue from injury.
At rest, a normal heart beats around 50 to 99 times a minute in an adult. Exercise, emotions, fever, and some medications can cause your heart to beat faster, sometimes to well over 100 beats per minute.
The term "heart disease" refers to several types of heart conditions. The most common type of heart disease in the United States is coronary artery disease (CAD). CAD affects the blood flow to the heart. Decreased blood flow can cause a heart attack.
Sometimes heart disease may be "silent" and not diagnosed until a person experiences signs or symptoms of a heart attack, heart failure, or an arrhythmia. When these events happen, symptoms may include:1
High blood pressure, high blood cholesterol, and smoking are key risk factors for heart disease. About half of people in the United States (47%) have at least one of these three risk factors.2 Several other medical conditions and lifestyle choices can also put people at a higher risk for heart disease, including
Cardiac rehabilitation is an important program for anyone recovering from a heart attack. This can also include heart failure, or some types of heart surgery. Cardiac rehabilitation is a supervised program that includes
The National Heart, Lung, and Blood Institute (NHLBI) provides global leadership for a research, training, and education program to promote the prevention and treatment of heart, lung, and blood disorders and enhance the health of all individuals so that they can live longer and more fulfilling lives.
Coronary artery disease is a common heart condition that affects the major blood vessels that supply the heart muscle. Cholesterol deposits (plaques) in the heart arteries are usually the cause of coronary artery disease. The buildup of these plaques is called atherosclerosis (ath-ur-o-skluh-ROE-sis). Atherosclerosis reduces blood flow to the heart and other parts of the body. It can lead to a heart attack, chest pain (angina) or stroke.
Coronary artery disease symptoms may be different for men and women. For instance, men are more likely to have chest pain. Women are more likely to have other symptoms along with chest discomfort, such as shortness of breath, nausea and extreme fatigue.
You might not be diagnosed with coronary artery disease until you have a heart attack, angina, stroke or heart failure. It's important to watch for heart symptoms and discuss concerns with your health care provider. Heart (cardiovascular) disease can sometimes be found early with regular health checkups.
Stephen Kopecky, M.D., Cardiovascular Disease, Mayo Clinic: I'm Dr. Stephen Kopecky, a cardiologist at Mayo Clinic. In this video, we'll cover the basics of coronary artery disease. What is it? Who gets it? The symptoms, diagnosis and treatment. Whether you're looking for answers for yourself or someone you love, we're here to give you the best information available.
Coronary artery disease, also called CAD, is a condition that affects your heart. It is the most common heart disease in the United States. CAD happens when coronary arteries struggle to supply the heart with enough blood, oxygen and nutrients. Cholesterol deposits, or plaques, are almost always to blame. These buildups narrow your arteries, decreasing blood flow to your heart. This can cause chest pain, shortness of breath or even a heart attack. CAD typically takes a long time to develop. So often, patients don't know that they have it until there's a problem. But there are ways to prevent coronary artery disease, and ways to know if you're at risk and ways to treat it.
Anyone can develop CAD. It begins when fats, cholesterols and other substances gather along the walls of your arteries. This process is called atherosclerosis. It's typically no cause for concern. However, too much buildup can lead to a blockage, obstructing blood flow. There are a number of risk factors, common red flags, that can contribute to this and ultimately lead to coronary artery disease. First, getting older can mean more damaged and narrowed arteries. Second, men are generally at a greater risk. But the risk for women increases after menopause. Existing health conditions matter, too. High blood pressure can thicken your arteries, narrowing your blood flow. High cholesterol levels can increase the rate of plaque buildup. Diabetes is also associated with higher risk, as is being overweight. Your lifestyle plays a large role as well. Physical inactivity, long periods of unrelieved stress in your life, an unhealthy diet and smoking can all increase your risk. And finally, family history. If a close relative was diagnosed at an early age with heart disease, you're at a greater risk. All these factors together can paint a picture of your risk for developing CAD.
When coronary arteries become narrow, the heart doesn't get enough oxygen-rich blood. Remember, unlike most pumps, the heart has to pump its own energy supply. It's working harder with less. And you may begin to notice these signs and symptoms of pressure or tightness in your chest. This pain is called angina. It may feel like somebody is standing on your chest. When your heart can't pump enough blood to meet your body's needs, you might develop shortness of breath or extreme fatigue during activities. And if an artery becomes totally blocked, it leads to a heart attack. Classic signs and symptoms of a heart attack include crushing, substernal chest pain, pain in your shoulders or arms, shortness of breath, and sweating. However, many heart attacks have minimal or no symptoms and are found later during routine testing.
Diagnosing CAD starts by talking to your doctor. They'll be able to look at your medical history, do a physical exam and order routine blood work. Depending on that, they may suggest one or more of the following tests: an electrocardiogram or ECG, an echocardiogram or soundwave test of the heart, stress test, cardiac catheterization and angiogram, or a cardiac CT scan.
Treating coronary artery disease usually means making changes to your lifestyle. This might be eating healthier foods, exercising regularly, losing excess weight, reducing stress or quitting smoking. The good news is these changes can do a lot to improve your outlook. Living a healthier life translates to having healthier arteries. When necessary, treatment could involve drugs like aspirin, cholesterol-modifying medications, beta-blockers, or certain medical procedures like angioplasty or coronary artery bypass surgery.
Discovering you have coronary artery disease can be overwhelming. But be encouraged. There are things you can do to manage and live with this condition. Reducing cholesterol, lowering blood pressure, quitting tobacco, eating healthier, exercising and managing your stress can make a world of difference. Better heart health starts by educating yourself. So don't be afraid to seek out information and ask your doctors about coronary artery disease. If you'd like to learn even more about this condition, watch our other related videos or visit Mayoclinic.org. We wish you well.
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