Angina is temporary moderate to severe pain or pressure in the chest. Sometimes the pain extends to the left shoulder and down the left arm or to the throat, jaw, and lower teeth. Occasionally it will reach the right side of the body. Many peo- ple describe their symptoms as discomfort rather than pain. Angina is caused by a lack of oxygen to the heart muscle.
Healthy coronary arteries can readily meet the heart’s demands for oxygen. However, if the coronary arteries have become narrowed or hardened as a result of atherosclerosis, they cannot supply adequate blood to the heart muscle during times of increased demand, resulting in angina.
Angina associated with coronary artery disease usually occurs during times of exertion, emotional stress, or after a large meal, when the heart pumps faster and harder, trying to keep up with the body’s increased oxygen demands. Often angina is worse when exertion follows a meal. Angina usually is worse in cold weather; walking into the wind or moving from a warm room to the cold air out- doors can trigger angina.
An episode of angina usually lasts fewer than 15 minutes and subsides with rest. Symptoms of angina that last longer than this may actually be a heart attack in progress, and you should seek immediate help. (See “Warning Signs of a Heart Attack,” page 209.) Since heart disease develops unnoticed in many peo- ple, angina is considered to be a beneﬁcial warning sign. If you experience angina, see your doctor as soon as possible.
Unstable angina refers to angina in which the established pattern of symptoms changes, or suddenly worsens. For example, angina pain usually remains con- stant and predictable from one episode to the next. But with unstable angina, the person may experience unpredictable changes, such as more severe pain, more frequent attacks, or attacks occurring with less exertion or during rest. These kinds of changes usually signal a rapid progression of coronary artery disease,
with increasing blockage of the coronary artery, possibly because a blood clot has formed or a piece of plaque has broken away from the artery wall. The risk of heart attack is high. Unstable angina is a medical emergency that requires immediate treatment.
Although angina is most often caused by coronary artery disease, it also can result from other factors, such as defects in the aortic valve. Because the aortic valve is near the opening of the coronary arteries, these abnormalities may reduce blood ﬂow into the coronary arteries and limit the amount of oxygen that goes to the heart. Another possible cause of angina is arterial spasm, in which, for reasons not fully understood, sudden temporary constriction or spasms occur in a coronary artery. Also, severe anemia (see page 238) may reduce the supply of oxygen to the heart, resulting in angina. Not everyone with an inadequate blood supply to the heart muscle experiences angina. Doctors do not yet under- stand why.
Angina is usually easy to recognize, but there are times when it mimics other conditions unrelated to the heart and blood vessels, such as indigestion and gas- troesophageal reﬂux disease (GERD; see page 262). Diagnosis can often be made by a physical examination and an exercise stress test (which evaluates heart rate, blood pressure, electrical activity of the heart, and symptoms of angina and other problems related to inadequate blood supply to the heart while a person walks or runs on a treadmill or rides a stationary bicycle).
Treatment for angina includes learning to reduce and deal positively with stress, decreasing cholesterol intake, and losing weight if you are overweight. A wide variety of medications are available that reduce blood pressure, slow the heart rate, or widen the blood vessels. In addition, other medications are avail- able that can help prevent the buildup of plaque in the arteries. If necessary, sur- gical procedures can be performed to bypass, clear, or widen the diseased coronary arteries.