Angina

Angina pectoris is a Latin phrase that means “strangling in the chest.” Patients often say that angina feels like a squeezing, suffocating, or burning sensation in their chest. An episode of angina is not a heart attack. Unlike a heart attack, the heart muscle is not damaged forever, and the pain often resolves with rest.

What Causes Angina?

Angina is heart muscle pain caused by ischemia, or a lack of oxygen. It occurs when blood vessels in the heart (coronary arteries) do not deliver enough blood to the heart muscle to meet its need for oxygen. The muscle’s deprivation of this oxygen-rich blood is called ischemia. Angina usually occurs when the heart muscle demands extra blood, such as during exercise. Other causes of angina can be emotional stress, extreme cold or hot temperatures, heavy meals, alcohol, and smoking.

Angina attacks in men usually happen after the age of 30 and are nearly always caused by coronary artery disease (CAD). Patients with angina have a greater chance of having a heart attack than those who have no symptoms of CAD.

For women, angina tends to happen later in life and can be caused by many different factors. Causes besides CAD include narrowing of the aortic valve in the heart (aortic stenosis), a low number of red blood cells in the bloodstream (anemia), or an overactive thyroid gland (hyperthyroidism).

Symptoms
Angina tends to start in the center of the chest, but may spread to the left arm, neck, back, throat, or jaw. Patients may experience numbness or loss of sensation in their arms, shoulders, or wrists. An episode only lasts a few minutes. Pain that lasts longer than a few minutes may indicate a sudden total blockage of a coronary artery or a heart attack.

Types of Angina

Stable Angina. Patients with stable angina usually know the level of activity or stress that causes an attack. These patients should keep track of how long their attacks last, if the attacks feel different from other attacks they have had, and whether medicine helps ease the symptoms. Sometimes the pattern changes—attacks occur more often, last longer, or happen without exercise.

Unstable Angina. A change in the pattern of attacks may indicate unstable angina. In this case, the patient should see their doctor as soon as possible. Patients who have new, worsening, or constant chest pain have a greater risk of heart attack, an irregular heartbeat (arrhythmia), and even sudden death.

Variant Angina Pectoris or Prinzmetal Angina. This rare form of angina is caused by coronary artery spasm (vasospasm). The spasm temporarily narrows the coronary artery and prevents the heart muscle from getting enough blood. It may occur in patients who have severe atherosclerosis in at least one major blood vessel. Unlike typical angina, variant angina usually occurs during times of rest. These attacks, which may be extremely painful, tend to regularly appear at certain times of the day.

Microvascular Angina or Cardiac Syndrome X. This type of angina occurs in patients who have chest pain but no coronary artery disease. The angina is caused when the tiny blood vessels that feed the heart, arms, and legs are not working properly. Patients generally cope well with this type of angina and have very few long-term side effects.

Diagnosis

Angina is usually diagnosed using the patient’s history of symptoms and patterns. Diagnostic tests performed may include x-rays, exercise electrocardiography (ECG), a nuclear stress test, and coronary angiography.

Variant angina can be diagnosed using a Holter monitor test. With certain types of monitors, the patient can push a “record” button to capture the rhythm when the angina symptoms occur.

Treatment

The most common ways to control angina are through changes in lifestyle and by taking medicine. A revascularization procedure may be necessary in severe cases.

Lifestyle

Although angina may occur during exercise, this does not mean that exercise should be avoided. In fact, the opposite is true. Patients should begin or continue an exercise program approved by their doctor. Risk factors for CAD (usually atherosclerosis) should be controlled, including high blood pressure, cigarette smoking, high cholesterol, and obesity. Patients who eat healthfully, stop smoking, limiting alcohol, and avoid stress live more comfortably and with fewer episodes of angina.

Medicine

Certain medicines may prevent or relieve angina symptoms. The most well-known medicine for angina is nitroglycerin. It works by dilating the blood vessels, which improves blood flow and allows more oxygen-rich blood to reach the heart muscle. Nitroglycerin works in seconds. Patients are usually instructed to sit or lie down and take their nitroglycerin as soon as an angina attack begins. If an activity such as climbing the stairs precedes angina, patients can take nitroglycerin beforehand to prevent an attack.

Other medicines used to control typical angina and microvascular angina are beta blockers and calcium channel blockers. These medicines reduce the oxygen needs of the heart by slowing the heart rate or lowering blood pressure. They also reduce the likelihood of an arrhythmia. Calcium channel blockers and nitrates may also be used to prevent the spasms that cause variant angina.

Patients with unstable angina are often prescribed bed rest and a  blood-thinning medicine (such as heparin).

Intervention and Surgery

If typical angina or variant angina is caused by severe coronary artery disease, then a revascularization procedure may be needed to improve blood supply to the heart. Procedures may include either a percutaneous coronary intervention (such as balloon angioplasty, atherectomy, or stenting) or coronary artery bypass surgery.


Resources

Texas Heart Institute www.texasheartinstitute.com/HIC/Topics/Cond/Angina.cfm

American Heart Association www.americanheart.org/presenter.jhtml?identifier=4472

Medline Plus www.nlm.nih.gov/medlineplus/angina.html

National Heart, Lung, and Blood Institute