Angina Health Article

Definition

Angina is pain, discomfort, or pressure in the chest that is caused by ischemia, an insufficient supply of oxygen-rich blood to the heart muscle. It is sometimes also characterized by a feeling of choking, suffocation, or crushing heaviness. This condition is also called angina pectoris.

Description

Often described as a muscle spasm and choking sensation, the term angina is used primarily to describe chest (thoracic) pain caused by insufficient oxygen to the heart muscle. An episode of angina is not an actual heart attack, but rather pain that results when the heart muscle temporarily receives too little blood. This temporary condition may be the result of demanding activities such as exercise and does not necessarily indicate that the heart muscle is experiencing permanent damage. In fact, episodes of angina seldom cause permanent damage to heart muscle.

Angina can be subdivided into two categories: angina of effort and variant angina.

Angina of effort

Angina of effort is a common disorder caused by the narrowing of the arteries (a condition called atherosclerosis) that supply oxygen-rich blood to the heart muscle. In the case of angina of effort, the coronary arteries can provide the heart muscle (myocardium) adequate blood during rest but not during periods of exercise, stress, or excitement. The resulting pain is relieved by resting or by administering nitroglycerin, a medication that relaxes the heart muscle, opens up the coronary blood vessels, and lowers the blood pressure—all of which reduce the heart's need for oxygen. Patients with angina of effort have an increased risk of heart attack (myocardial infarction).

Variant angina

Variant angina is uncommon and occurs independently of atherosclerosis, which may incidentally be present. Variant angina occurs at rest and is not related to excessive work by the heart muscle. Research indicates that variant angina is caused by coronary artery muscle spasm that does not last long enough or is not intense enough to cause an actual heart attack.

Causes & symptoms

Angina is usually caused by an underlying obstruction to the coronary artery due to atherosclerosis. In some cases, it is caused by spasm that occurs naturally or as a result of ingesting cocaine. In rare cases, angina is caused by a coronary embolism or by a disease other than atherosclerosis that places demands on the heart.

Most episodes of angina are brought on by physical exertion, when the heart needs more oxygen than is available from the blood nourishing the heart. Emotional stress, extreme temperatures, heavy meals, cigarette smoking, and alcohol can also cause or contribute to an episode of angina.

Angina causes a pressing pain or sensation of heaviness, usually in the chest area under the breast bone (sternum). It is occasionally experienced in the shoulder, arm, neck, or jaw regions. In most cases, the symptoms are relieved within a few minutes by resting or by taking prescribed angina medications.

Diagnosis

Physicians can usually diagnose angina based on the patient's symptoms and the precipitating factors. However, other diagnostic testing is often required to confirm or rule out angina, or to determine the severity of the underlying heart disease.

Electrocardiogram (ECG)

An electrocardiogram is a test that records electrical impulses from the heart. The resulting graph of electrical activity can show if the heart muscle isn't functioning properly as a result of a lack of oxygen. Electrocardiograms are also useful in investigating other possible abnormal features of the heart, such as arrhythmia (irregular heartbeat).

Stress test

For many individuals with angina, the results of an electrocardiogram while at rest will not show any abnormalities. Because the symptoms of angina occur during stress, the heart's function may need to be evaluated under the physical stress of exercise. The stress test records information from the electrocardiogram before, during, and after exercise in search of stress-related abnormalities. Blood pressure is also measured during the stress test and symptoms are noted. In some cases a more involved and complex stress test (for example, thallium scanning) is used to picture the blood flow in the heart muscle during the most intense exercise and after rest.

Angiogram

The angiogram, which is a series of x rays of the coronary artery, has been noted as the most accurate diagnostic test to indicate the presence and extent of coronary disease. In this procedure, a long, thin, flexible tube (catheter) is inserted into an artery located in the forearm or groin. This catheter is passed further through the artery into one of the two major coronary arteries. A dye is injected through the catheter to make the heart, arteries, and blood flow clearer on the x ray. A fluoroscopic film, or series of "moving" x rays, shows the blood flowing through the coronary arteries. This will reveal any possible narrowing that can cause a decrease in blood flow to the heart muscle and associated symptoms of angina.