Angina pectoris

Definition

Angina pectoris Definition Angina pectoris is chest pain, often experienced as feelings of tightness, squeezing, heaviness or vise-like pressure that occurs when the heart does not get an is usually relieved quickly by rest or nitrate drugs.

Description

Angina pectoris, often referred to as angina, is the medical term for chest pain that usually results from coronary heart disease. Other kinds of chest pain, such as heartburn resulting from acid reflux disease, or pain from an infection of the lungs, are not considered angina.

There are two broad classes of angina: stable angina and unstable angina. Stable angina, also called chronic stable angina, describes the condition where people experience a predictable pattern of chest pain that results from an existing degree of insufficient blood flow to the heart. For example, many people experience angina on exertion, such as when running or lifting a heavy object, or in times of emotional stress .

Unstable angina generally occurs at rest, without an obvious trigger or causative event. Unstable angina is usually a response to sharply reduced blood flow to the heart muscle, which may be caused by constriction or blockage of one or more coronary arteries, the blood vessels that supply the heart. Obstructions, hardening and narrowing of the coronary arteries may be due to atherosclerosis (the buildup of fatty substances called plaque on the walls of the coronary arteries) or may be caused by a new blood clot.

Unstable angina also describes the situation in which a person has the new occurrence of angina (called new onset angina) or angina provoked by much less exertion than had previously been required (sometimes called crescendo angina). Unstable angina may be caused by inflammation or infection. New or worsening unstable angina is considered a medical emergency because patients are at increased risk of heart attack , serious heart rhythm problems, and cardiac arrest.

Another, much less common variation of angina pectoris is called Prinzmetal's angina. It occurs at rest and without warning and it is not triggered by exertion or emotional stress. Most attacks of Prinzmetal's angina occur at night, between midnight and 8 A.M. This type of angina is caused by a coronary artery spasm that sharply limits blood flow to the heart. Many patients have atherosclerosis; coronary artery spasms frequently occur near blockages in the coronary arteries.

Demographics

Angina is a symptom of ischemic heart disease , which is the leading cause of death in the United States and the developed world. Angina affects about nine million people in the United States.

The incidence of angina increases with advancing age. About 40% of people with angina are age 65 or older, and men are more likely to develop the disease than women. Smoking, high cholesterol levels, high blood pressure , diabetes, obesity , and a family history of ischemic heart disease all act to increase the risk of developing angina.

Causes and symptoms

Angina pectoris is not a disease; it is a symptom of myocardial ischemia , inadequate flow of blood and oxygen to the heart muscle. Narrowing or obstruction of one or more of the arteries that supply blood to the heart muscle often causes angina pectoris. Less frequently, angina may be caused by valvular heart disease, an enlarged heart, or uncontrolled high blood pressure. Because it is a symptom of underlying coronary artery disease, a person with angina is considered at increased risk of serious heart problems such as heart attack, cardiac arrest, and sudden cardiac death.

Angina often occurs when the heart makes an increased demand for blood as it does during exercise or in extreme temperatures. Angina may be triggered by sudden or strong emotions. Angina also may occur when a person is at rest, when the heart has not increased its demand for blood and oxygen. This instance of angina may be caused by worsening blockage of a coronary artery, or by a coronary artery spasm, which temporarily sharply reduces or entirely stops blood flow to the heart.

The pain or discomfort associated with angina is often experienced as pressure, fullness, or squeezing in the center of the chest below the breastbone. Although the heart is the origin of the pain, the pain and discomfort may radiate, spreading to the neck, jaw, shoulder, back or arm. Other symptoms of angina include shortness of breath, breaking out in a cold sweat, and feeling lightheaded or nauseated.

Diagnosis

Angina pectoris is diagnosed on the basis of a physical examination and medical history with special attention to the occurrence of symptoms. One or more of the following diagnostic tests may be performed:

• Electrocardiogram (ECG) and treadmill exercise tests record and document the heart's electrical activity, including changes that may occur when the heart has to work harder.
• Blood tests to measure fasting blood glucose, lipid profile, and serum hemoglobin may be used to identify the presence of associated risk factors, such as diabetes, high cholesterol, and anemia.
• Chest x rays can detect heart failure, enlarged heart, and aortic dissection, as well as valvular heart disease and serious lung disease.
• Stress echocardiogram is an exercise test that uses ultrasound to evaluate the heart's ability to contract and pump when increased demands are placed on it.
• Nuclear heart scans show how well blood is pumped through the heart and can assess the overall pumping strength of the heart.
• Coronary angiogram is a test using contrast dye and x rays trace blood flow through the heart and determine if and where the coronary arteries are clogged.

Treatment

Angina treatment often involves treating its underlying causes. Angina caused by coronary artery disease is often treated with lifestyle measures that include:

• smoking cessation
• weight loss
• regular exercise
• reducing elevated blood pressure
• reducing elevated blood sugar
• reducing elevated blood cholesterol
• effectively managing stress

Angina may be treated with prescription drugs such as nitroglycerin, which increases blood flow to the heart by dilating the coronary blood vessels and lowering blood pressure slightly. Beta blockers and calcium channel blockers are also prescribed to treat angina. Other drugs that may be used to control angina include angiotensin-converting enzyme (ACE) inhibitors, aspirin , and cholesterol-lowering medicines.

When angina is the result of blocked arteries it may be treated with procedures aimed at clearing the obstruction. Percutaneous coronary intervention and bypass surgery are procedures that aim to improve blood flow in the coronary arteries. Percutaneous coronary intervention, also called coronary angioplasty or PCI, is a non-surgical procedure. A catheter tipped with a balloon is threaded through an artery in the groin into the blocked coronary artery. The balloon is inflated, compressing the plaque to enlarge the blood vessel and open the blocked artery. The balloon is deflated, and the catheter is removed. PCI is less invasive and less expensive than coronary artery bypass surgery.

In coronary artery bypass graft (CABG) surgery, a healthy vein from an arm, leg, or the internal mammary artery is used to build a detour (bypass) around the coronary artery blockage. Bypass surgery is appropriate for patients with blockages in two or three major coronary arteries, those with severely narrowed left main coronary arteries, and those who have not responded to other treatments. CABG is performed in a hospital under general anesthesia . A heart-lung machine is used to support the patient while the healthy vein or artery is attached around the blockage to the coronary artery. About 70% of patients who have bypass surgery experience complete relief from angina; about 20% experience partial relief.

Nutrition/Dietetic concerns

Patients with angina who are overweight are advised to begin a weight-loss program under the supervision of a health professional. Patients who are at a healthy weight are counseled to eat a varied, well-balanced diet and to avoid foods high in cholesterol or saturated fat,

Prognosis

The outlook for patients with angina is usually very good. By making appropriate lifestyle changes and adhering to prescribed treatment, most patients with angina can minimize the frequency of attacks and can lead active, normal lives.

Prevention

Preventing angina attacks involves taking measures to lead a healthy lifestyle and following prescribed treatment. Several actions can help prevent angina:

• embarking on a regular exercise program under the supervision of a health professional
• maintaining a healthy weight; persons who are overweight should begin a weight-loss program under the supervision of a health professional
• eating a balanced, varied diet and avoid consumption of foods that are high in cholesterol and saturated fat
• getting regular blood pressure checks, because high blood pressure increases risk of angina
• avoiding stressful situations and learning to manage stress effectively
• adhering to prescribed medication regimens

When slowing down or stopping an activity does not relieve angina or if pain occurs at rest nitroglycerin can be taken. Some patients with angina prevent symptoms by taking nitroglycerin before activities that usually cause angina.

QUESTIONS TO ASK YOUR DOCTOR

• What is the best action to take when an angina attack occurs?
• How can the frequency of angina attacks be reduced?
• Is it safe to engage in sports or sexual activity?
• Is it safe to use drugs for erectile dysfunction, such as sildenafil (Viagra), if I have a history of angina?

KEY TERMS

Angina —Chest pain that occurs when diseased blood vessels restrict the flow of blood to the heart muscle. Angina is often the first symptom of coronary artery disease.

Atherosclerosis —A process in which the walls of the coronary arteries thicken due to the accumulation of plaque in the blood vessels. Atherosclerosis is the cause of coronary artery disease.

Coronary arteries —The two arteries that provide blood to the heart. The coronary arteries surround the heart like a crown, coming out of the aorta, arching down over the top of the heart, and dividing into two branches. These are the arteries in which coronary artery disease occurs.

Myocardial ischemia —Insufficient blood flow to part of the heart.

Caregiver concerns

Persons diagnosed with angina and coronary artery disease frequently develop depression as well. They may fear that their careers or lives will be compromised and may experience anxiety about the occurrence of angina attacks. Support and reassurance from caregivers may help to ease these fears.

Resources

BOOKS

Gibbons, R. J., J. Abrams, K. Chatterjee, et al. ACC/AHA 2002 Guideline Update for the Management of Patients with Chronic Stable Angina: A Report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Committee to Update the 1999 Guidelines). Bethesda, MD: American College of Cardiology Foundation, 2002.

PERIODICALS

Snow, V., et al. “Evaluation of Primary Care Patients with Chronic Stable Angina: Guidelines from the American College of Physicians”. Annals of Internal Medicine 141, no.1 (July 6, 2004).

Snow, V., et al. “Primary Care Management of Chronic Stable Angina and Asymptomatic Suspected or Known Coronary Artery Disease: A Clinical Practice Guideline from the American College of Physicians.” Annals of Internal Medicine 141, no.1 (July 6, 2004).

OTHER

“Heart Disease: Angina.” WebMD December 1, 2006 [cited April 2, 2008]. The Cleveland Clinic Heart Center. http://www.webmd.com/heart-disease/guide/heart-disease-angina

Kelly, Robert B. ed. “Angina and Heart Disease.

” familydoctor.org. November 2006 [cited April 2, 2008]. http://familydoctor.org/online/famdocen/home/common/heartdisease/basics/233.html.

ORGANIZATIONS

American Heart Association, 7272 Greenville Avenue, Dallas, TX, 75231, (301) 592-8573, (800) 242-8721, (301) 592-8563, www.americanheart.org.

National Heart, Lung, and Blood Institute, PO Box 30105, Bethesda, MD, 20824-0105, (301) 592-8573, (800) 242-8721, (301) 592-8563, www.nhlbi.nih.gov.

Barbara Wexler MPH