Coronary Artery Disease
Coronary artery disease develops when your coronary arteries (the major blood vessels that supply your heart with blood, oxygen and nutrients) become damaged or diseased. Cholesterol-containing deposits (plaque) on your arteries are usually to blame for coronary artery disease.
When plaques build up, they narrow your coronary arteries, causing your heart to receive less blood. Eventually, the decreased blood flow may cause chest pain (angina), shortness of breath, or other coronary artery disease signs and symptoms. A complete blockage can cause a heart attack.
Because coronary artery disease often develops over decades, it can go virtually unnoticed until you have a heart attack. But there's plenty you can do to prevent and treat coronary artery disease. Start by committing to a healthy lifestyle.
If your coronary arteries become narrowed, they can't supply enough oxygen-rich blood to your heart — especially when it's beating hard, such as during exercise. At first, the decreased blood flow may not cause any coronary artery disease symptoms. As the plaques continue to build up in your coronary arteries, however, you may develop coronary artery disease symptoms, including:
Chest Pain (Angina) You may feel pressure or tightness in your chest, as if someone were standing on your chest. The pain, referred to as angina, is usually triggered by physical or emotional stress. It typically goes away within minutes after stopping the stressful activity. In some people, especially women, this pain may be fleeting or sharp and noticed in the abdomen, back or arm.
Shortness of Breath If your heart can't pump enough blood to meet your body's needs, you may develop shortness of breath or extreme fatigue with exertion.
Heart Attack If a coronary artery becomes completely blocked, you may have a heart attack. The classic signs and symptoms of a heart attack include crushing pressure in your chest and pain in your shoulder or arm, sometimes with shortness of breath and sweating. Women are somewhat more likely than men are to experience less typical signs and symptoms of a heart attack, including nausea and back or jaw pain. Sometimes a heart attack occurs without any apparent signs or symptoms.
When to see a doctor
If you suspect you're having a heart attack, immediately call 911 or your local emergency number. If you don't have access to emergency medical services, have someone drive you to the nearest hospital. Drive yourself only as a last resort.
If you have risk factors for coronary artery disease — such as high blood pressure, high cholesterol, diabetes or obesity — talk to your doctor. He or she may want to test you for the condition, especially if you have signs or symptoms of narrowed arteries. Even if you don't have evidence of coronary artery disease, your doctor may recommend aggressive treatment of your risk factors. Early diagnosis and treatment may stop progression of coronary artery disease and help prevent a heart attack.
Coronary artery disease is thought to begin with damage or injury to the inner layer of a coronary artery, sometimes as early as childhood. The damage may be caused by various factors, including:
High blood pressure
High cholesterol Diabetes
Radiation therapy to the chest, as used for certain types of cancer
Once the inner wall of an artery is damaged, fatty deposits (plaques) made of cholesterol and other cellular waste products tend to accumulate at the site of injury in a process called atherosclerosis. If the surface of these plaques breaks or ruptures, blood cells called platelets will clump at the site to try to repair the artery. This clump can block the artery, leading to a heart attack.
Risk factors for coronary artery disease include:
Age, Simply getting older increases your risk of damaged and narrowed arteries.
Sex, Men are generally at greater risk of coronary artery disease. However, the risk for women increases after menopause.
Family history, A family history of heart disease is associated with a higher risk of coronary artery disease, especially if a close relative developed heart disease at an early age. Your risk is highest if your father or a brother was diagnosed with heart disease before age 55, or your mother or a sister developed it before age 65.
Smoking, Nicotine constricts your blood vessels, and carbon monoxide can damage their inner lining, making them more susceptible to atherosclerosis. The incidence of heart attack in women who smoke at least 20 cigarettes a day is six times that of women who've never smoked. For men who smoke, the incidence is triple that of nonsmokers.
High blood pressure, Uncontrolled high blood pressure can result in hardening and thickening of your arteries, narrowing the channel through which blood can flow.
High blood cholesterol levels, High levels of cholesterol in your blood can increase the risk of formation of plaques and atherosclerosis. High cholesterol can be caused by a high level of low-density lipoprotein (LDL), known as the "bad" cholesterol. A low level of high-density lipoprotein (HDL), known as the "good" cholesterol, also can promote atherosclerosis.
Diabetes, Diabetes is associated with an increased risk of coronary artery disease. Both conditions share similar risk factors, such as obesity and high blood pressure.
Obesity, Excess weight typically worsens other risk factors.
Physical inactivity, Lack of exercise also is associated with coronary artery disease and some of its risk factors, as well.
High stress. Unrelieved stress in your life may damage your arteries as well as worsen other risk factors for coronary artery disease.
Risk factors often occur in clusters and may build on one another, such as obesity leading to diabetes and high blood pressure. When grouped together, certain risk factors put you at an ever greater risk of coronary artery disease. For example, metabolic syndrome — a cluster of conditions that includes elevated blood pressure, high triglycerides, elevated insulin levels and excess body fat around the waist — increases the risk of coronary artery disease.
Sometimes coronary artery disease develops without any classic risk factors. Researchers are studying other possible factors, including: Sleep apnea. This disorder causes you to repeatedly stop and start breathing while you're sleeping. Sudden drops in blood oxygen levels that occur during sleep apnea increase blood pressure and strain the cardiovascular system, possibly leading to coronary artery disease.
C-reactive protein, C-reactive protein (CRP) is a normal protein that appears in higher amounts when there's swelling somewhere in your body. High CRP levels may be a risk factor for heart disease. It's thought that as coronary arteries narrow, you'll have more CRP in your blood. Homocysteine. Homocysteine is an amino acid your body uses to make protein and to build and maintain tissue. But high levels of homocysteine may increase your risk of coronary artery disease.
Fibrinogen. Fibrinogen is a protein in your blood that plays a central role in blood clotting. But too much may increase clumping of platelets, the type of blood cell largely responsible for clotting. That can cause a clot to form in an artery, leading to a heart attack or stroke. Fibrinogen may also be an indicator of the inflammation that accompanies atherosclerosis. Lipoprotein (a). This substance forms when a low-density lipoprotein (LDL) particle attaches to a specific protein. Lipoprotein (a) may disrupt your body's ability to dissolve blood clots. High levels of lipoprotein (a) may be associated with an increased risk of cardiovascular disease, including coronary artery disease and heart attack.
Coronary artery disease can lead to:
Chest Pain (Angina) When your coronary arteries narrow, your heart may not receive enough blood when demand is greatest — particularly during physical activity. This can cause chest pain (angina) or shortness of breath.
Heart Attack If a cholesterol plaque ruptures and a blood clot forms, complete blockage of your heart artery may trigger a heart attack. The lack of blood flow to your heart may damage to your heart muscle. The amount of damage depends in part on how quickly you receive treatment.
Heart Failure If some areas of your heart are chronically deprived of oxygen and nutrients because of reduced blood flow, or if your heart has been damaged by a heart attack, your heart may become too weak to pump enough blood to meet your body's needs. This condition is known as heart failure. Abnormal heart rhythm (arrhythmia). Inadequate blood supply to the heart or damage to heart tissue can interfere with your heart's electrical impulses, causing abnormal heart rhythms.