What Is Angina?
Angina pectoris is the medical term for chest pain or discomfort due to coronary heart disease. Angina is a symptom of a condition called myocardial ischemia. It occurs when the heart muscle (myocardium) doesn't get as much blood (hence as much oxygen) as it needs. This usually happens because one or more of the heart's arteries (coronary blood vessels that supply blood to the heart muscle) is narrowed or blocked. Insufficient blood supply is called ischemia.
Angina also can occur in people with valvular heart disease, hypertrophic cardiomyopathy (this is an enlarged heart due to disease) or uncontrolled high blood pressure. These cases are rare, though.
Typical angina is uncomfortable pressure, fullness, squeezing or pain in the center of the chest. The discomfort also may be felt in the neck, jaw, shoulder, back or arm. Many types of chest discomfort aren't related to angina. Acid reflux (heartburn) and lung infection or inflammation are examples.
What causes angina?
The most common cause of angina is coronary artery disease. A less common cause of angina is spasm of the coronary arteries.
Coronary artery disease
Coronary arteries supply oxygenated blood to the heart muscle. Coronary artery disease develops as cholesterol is deposited in the artery wall, causing the formation of a hard, thick substance called cholesterol plaque. The accumulation of cholesterol plaque over time causes narrowing of the coronary arteries, a process called arteriosclerosis. Arteriosclerosis can be accelerated by smoking, high blood pressure, elevated cholesterol, and diabetes. When coronary arteries become narrowed by more than 50% to 70%, they can no longer meet the increased blood oxygen demand by the heart muscle during exercise or stress. Lack of oxygen to the heart muscle causes chest pain (angina).
Coronary artery spasm
The walls of the arteries are surrounded by muscle fibers. Rapid contraction of these muscle fibers causes a sudden narrowing (spasm) of the arteries. A spasm of the coronary arteries reduces blood to the heart muscle and causes angina. Angina as a result of a coronary artery spasm is called "variant" angina or Prinzmetal angina. Prinzmetal angina typically occurs at rest, usually in the early morning hours. Spasms can occur in normal coronary arteries as well as in those narrowed by arteriosclerosis.
Coronary artery spasm can also be caused by use/abuse of cocaine. The spasm of the artery wall caused by cocaine can be so significant that it can actually cause a heart attack.
How Is Angina Treated?
Treatments for angina include lifestyle changes, medicines, medical procedures, and cardiac rehabilitation (rehab). The main goals of treatment are to:
- Reduce pain and discomfort and how often it occurs
- Prevent or lower the risk of heart attack and death by treating the underlying heart condition
Lifestyle changes and medicines may be the only treatments needed if your symptoms are mild and aren't getting worse. When lifestyle changes and medicines don't control angina, you may need medical procedures or cardiac rehab.
Unstable angina is an emergency condition that requires treatment in the hospital.
Lifestyle Changes
Making lifestyle changes can help prevent episodes of angina. You can:
- Slow down or take rest breaks if angina comes on with exertion.
- Avoid large meals and rich foods that leave you feeling stuffed if angina comes on after a heavy meal.
- Try to avoid situations that make you upset or stressed if angina comes on with stress. Learn ways to handle stress that can't be avoided.
You also can make lifestyle changes that help lower your risk of heart disease. An important lifestyle change is adopting a healthy diet. This will help prevent or reduce high blood pressure, high blood cholesterol, and obesity.
Follow a heart healthy eating plan that focuses on fruits, vegetables, whole grains, low-fat or no-fat diary products, and lean meat and fish. The plan also should be low in salt, fat, saturated fat, trans fat, and cholesterol.
Examples of healthy eating plans are the National Heart, Lung, and Blood Institute's Therapeutic Lifestyle Changes (TLC) diet and the Dietary Approaches to Stop Hypertension (DASH) eating plan.
Your doctor may recommend TLC if you have high cholesterol or the DASH eating plan if you have high blood pressure. Even if you don't have these conditions, you can still benefit from these heart healthy plans.
Other important lifestyle changes include:
- Quitting smoking, if you smoke. Avoid secondhand smoke.
- Being physically active. Check with your doctor to find out how much and what kinds of activity are safe for you.
- Losing weight, if you're overweight or obese.
- Taking all medicines as your doctor prescribes, especially if you have diabetes.
Medicines
Nitrates are the most commonly used medicines to treat angina. They relax and widen blood vessels. This allows more blood to flow to the heart while reducing its workload.
Nitroglycerin is the most commonly used nitrate for angina. Nitroglycerin that dissolves under your tongue or between your cheeks and gum is used to relieve an angina episode. Nitroglycerin in the form of pills and skin patches is used to prevent attacks of angina. These forms of nitroglycerin act too slowly to relieve pain during an angina attack.
You also may need other medicines to treat angina. These medicines may include beta blockers, calcium channel blockers, ACE inhibitors, oral antiplatelet (an-ty-PLAYT-lit) medicines, and anticoagulants (AN-te-ko-AG-u-lants). These medicines can help:
- Lower blood pressure and cholesterol levels
- Slow the heart rate
- Relax blood vessels
- Reduce strain on the heart
- Prevent blood clots from forming
Medical Procedures
When medicines and other treatments don't control angina, you may need a medical procedure to treat the underlying heart disease. Angioplasty (AN-jee-oh-plas-tee) and coronary artery bypass grafting (CABG) are both commonly used to treat angina.
Angioplasty opens blocked or narrowed coronary arteries. During angioplasty, a thin tube with a balloon or other device on the end is threaded through a blood vessel to the narrowed or blocked coronary artery. Once in place, the balloon is inflated to push the plaque outward against the wall of the artery. This widens the artery and restores blood flow.
Angioplasty can improve blood flow to your heart, relieve chest pain, and possibly prevent a heart attack. Sometimes a small mesh tube called a stent is placed in the artery to keep it open after the procedure.
During CABG, healthy arteries or veins taken from other areas in your body are used to bypass (that is, go around) your narrowed coronary arteries. Bypass surgery can improve blood flow to your heart, relieve chest pain, and possibly prevent a heart attack.
Your doctor will help decide which treatment is right for you.
Cardiac Rehabilitation
Your doctor may prescribe cardiac rehab for angina or after angioplasty, CABG, or a heart attack.
The cardiac rehab team may include doctors, nurses, exercise specialists, physical and occupational therapists, dietitians, and psychologists or other behavioral therapists.
Rehab has two parts:
- Exercise training. This part helps you learn how to exercise safely, strengthen your muscles, and improve your stamina. Your exercise plan will be based on your individual abilities, needs, and interests.
- Education, counseling, and training. This part of rehab helps you understand your heart condition and find ways to reduce your risk of future heart problems. The cardiac rehab team will help you learn how to cope with the stress of adjusting to a new lifestyle and to deal with your fears about the future.