Angina pectoris

Angina pectoris is chest pain caused by inadequate circulation of blood to the heart muscle tissues. The most common cause of angina is coronary artery disease (CAD).


Causes/associated factors
The coronary arteries supply blood and oxygen to the heart. Coronary artery disease is a condition that develops when these arteries become lined with deposits called plaque. The plaque narrows the diameter of the blood vessels, which reduces the amount of blood flow. This, in turn, decreases the oxygen supply to the heart. This reduced blood flow can produce chest pain, especially when accompanied by exercise or emotional stress. This type of chest pain is known as stable angina.
For unknown reasons, the plaque inside the artery may also break and form a clot at the rupture site. This clot can suddenly cause reduced blood flow to the heart, which may result in unstable angina. Severely reduced blood flow can cause a heart attack.

Stable angina has consistent symptoms and a more predictable pattern than unstable angina, which is associated with a higher heart attack risk. Unstable angina is often characterized by chest pain that's more frequent, more severe and less responsive to medication. It may occur at rest, at night or with minimal exertion.

Coronary artery disease is more common among older adults. CAD affects men at a younger age than women, however. In fact, about 70 percent of all people who have angina pectoris are men. For women, the risk of CAD increases after menopause. By age 60 to 65, women develop CAD at the same rate as men.

A family history of CAD is a significant risk factor. Other major risk factors for CAD include:

smoking
high blood pressure
high cholesterol
diabetes
obesity
physical inactivity
During an episode of angina, the nerves in the heart send a message of pain to the brain. An angina attack can be triggered by activities or situations that make the heart work harder and demand more oxygen, including:

exercise
emotional upset
stress
exposure to extreme temperatures
a heavy meal

Signs/symptoms
Symptoms vary when chest pain is caused by a cardiac problem.
The classic symptoms of stable angina are chest pain or shortness of breath triggered by exercise, exertion or emotional stress. These symptoms are relieved within minutes by rest or prescribed nitroglycerin tablets.

Some people describe angina as a tight, band-like crushing or squeezing sensation often located in the center of the front of the chest. Pain can spread to the throat, neck, jaw, shoulder, back, either arm or any part of the body in a radius around the heart.

Women and people who have certain medical conditions, such as diabetes, often have different symptoms. In these cases, symptoms may include shortness of breath (sometimes with very little exertion), fatigue with exertion or pain in the left shoulder. Or, there may be no symptoms at all. Unfortunately, atypical symptoms may cause treatment to be delayed or less aggressive.

Other symptoms may include:

Levine's sign, a feeling of heaviness or constriction in the chest that may be distinguished by clenching a fist over the midchest
choking sensation
indigestion, gas pain, or burning sensation in the midchest or upper abdomen
chest pain at rest (This is often a symptom of unstable angina or even a heart attack.)
Some noncardiac conditions may cause chest pain as well, including:

esophagitis or irritation to the esophagus (Potential causes may include reflux, when stomach acid or gases flow upward into the esophagus, medications that weren't completely swallowed and are still in the esophagus, esophageal spasm and hiatal hernia, the protrusion of part of the stomach from its normal position in the abdomen through the diaphragm.)
anxiety attacks or panic disorders
pulmonary embolism (a blood clot in the lungs) or pulmonary hypertension (high blood pressure in the pulmonary arteries)
spontaneous pneumothorax (rupture of the lung or a portion of it)
aortic dissection (rupture of layers of the large artery from the heart)
cholecystitis (inflammation of the gallbladder), with or without gallstones
joint disease of the shoulder
costochondritis (inflammation of rib cartilage)
Symptoms that require emergency medical attention
Seek emergency medical help immediately if you have severe chest pain or discomfort that's not relieved by rest and nitroglycerin tablets. Don't hesitate to seek help if the pain is worse than you've experienced before or increases with each breath.

Other symptoms that require emergency medical attention include chest pain or discomfort accompanied by any of the following symptoms or conditions:

sweating or clamminess
nausea or vomiting
shortness of breath
dizziness or weakness
fainting
feelings of impending doom or distress
rapid or irregular heartbeat
rapid breathing
pain that radiated to the arm, jaw, back, shoulder or neck
blue nail beds
change in level of consciousness
pain that's unaffected by movement or a change in position
recent cocaine use
loss of arm or leg function, speech or vision

Diagnosis
The doctor will review your medical history and do a physical exam. To determine the presence and extent of CAD, other heart disease or circulatory problems, you may also need one or more of the following tests:
electrocardiogram (a recording of the electrical activity of the heart)
blood and urine tests
chest X-ray
exercise stress test (with heart monitoring and often radioactive thallium, a substance that will appear on an X-ray to help doctors diagnose impaired coronary blood flow)
medication stress test (for people who are unable to walk)
echocardiogram (using sound waves to study the heart), possibly in combination with an exercise stress test
coronary angiogram (an imaging technique that allows the study of blood vessels through injection of contrast dye, a substance used with various imaging techniques)
electrophysiologic heart studies (tests that use a catheter threaded into the heart to detect and map irregular heartbeats)
electron beam tomography (EBT, a computed tomography scan of the heart that can detect calcium deposits on the coronary arteries)

Treatment
You can help prevent heart attacks and other complications of angina and coronary artery disease by seeking early treatment. Your doctor may recommend lifestyle modifications to reduce any risk factors. Any underlying conditions will also be corrected. In some cases, medication, surgery or other procedures are needed.
Lifestyle modifications
To minimize your heart's workload, maintain a healthy weight. If you're overweight, lose the excess pounds. Your doctor may also recommend a diet high in fiber and low in fat, cholesterol and sodium.

Weight loss and dietary benefits: Obesity increases the risk of coronary artery disease, high blood pressure and diabetes. Maintaining an optimal weight puts less stress on your heart. Low-fat, low-cholesterol, low-sodium diets have been shown to lower blood pressure and cholesterol, as well as slow the progression of atherosclerosis.

Weight loss and dietary risks: Changing your lifelong eating habits can be difficult to do and maintain. You must be committed to making the change. You may need to learn about nutrition as well.
Work with your doctor to coordinate a safe aerobic exercise program.

Exercise benefits: Exercise improves insulin resistance and increases HDL or "good" cholesterol. Aerobic exercise and getting in shape will condition your muscles, lower your heart rate, and lower the oxygen demands placed on your heart. It can decrease your symptoms and improve your quality of life. It can also decrease the risk of dying from heart conditions. Some exercise is better than none at all. Always check with your doctor before beginning an exercise program.

Exercise risks: Only about half of all people who begin exercise programs continue for more than six months. Improper form may lead to injuries. Isometric exercise (such as weight training) can raise blood pressure and increase oxygen demand on the heart.
Learn to manage your stress.

Stress management benefits: Biofeedback and other relaxation techniques can help control or reduce stress and anger, which have been shown to trigger angina as well as other heart-related events. Reducing stress may help you smoke less and resist the temptation to eat "comfort food."

Stress management risks: Studies give mixed results on the relationship between psychological interventions and heart-related events.
If you smoke, quit.

Smoking cessation benefits: Smoking worsens atherosclerosis, increases the heart's demand for oxygen, and can make angina more severe. Quitting smoking reduces the risk of dying from heart disease.

Smoking cessation risks: Smoking can be a difficult habit to break.
Medications
Medication can help control symptoms of angina. Although medications may not clear blocked arteries, they help relieve angina by increasing the blood supply to your heart or decreasing your heart's workload. Three types of medications, known as beta blockers, nitrates and calcium channel blockers, are generally effective in relieving angina pain.

Beta blockers slow heart rate and lower blood pressure.

Beta blocker benefits: Beta blockers reduce the amount of oxygen required by the heart and decrease the heart's workload.

Beta blocker risks: Side effects include dizziness. Beta blockers aren't recommended for people who have certain respiratory problems, such as asthma. Other possible side effects may include drowsiness, fatigue, lower libido or, for men, erectile dysfunction (impotence).
Nitrates (such as isosorbide and nitroglycerin) open the coronary arteries so more blood can flow to the heart muscle. Nitrates also open other vessels, which lowers blood pressure and eases the heart's workload.

Nitrate benefits: Nitrates relieve chest pain quickly and can be taken under the tongue (sublingual), through a spray (translingual), or held between the cheek and gum (intrabuccal). Oral capsules are also available. For maintenance therapy, cream can be applied to the skin or a skin patch can be worn. Nitrates are an option for people who have Prinzmetal's angina (chest pain caused by a coronary artery spasm that usually occurs while resting).
Note: If the pain doesn't respond to nitroglycerin within 15 minutes, seek emergency medical attention.


Nitrate risks: After you take a dose of nitroglycerin under the tongue, you may get a headache. The headaches usually subside with continued use. Other possible side effects of nitrates (taken in any fashion) include flushing, a pulsating sensation in the head, dizziness upon standing and, sometimes, nausea and vomiting. If you notice these side effects, sit up in bed or a chair. Nitrates can also cause reflex tachycardia (when the heartbeat accelerates in response to a stimulus outside the heart). Men who take certain erectile dysfunction medications should not take nitrates. Discuss the risk of any potential medication interactions with your doctor.
Antiplatelet medications help prevent blood from clotting. Antiplatelet therapy is usually recommended for people who have coronary artery disease and stable or unstable angina. Aspirin and clopidogrel bisulfate (Plavix, for example) are common choices. A new class of medications, glycoprotein antagonists, are given intravenously in the hospital to treat unstable angina. They're often used in combination with angioplasty. Examples include tirofiban (Aggrastat, for example), eptifibatide (Integrilin, for example) and abciximib (ReoPro, for example).

Antiplatelet benefits: Antiplatelet medications may prevent angina from becoming unstable and progressing to a heart attack.

Antiplatelet risks: Antiplatelet medications may increase the risk of bleeding.
Calcium channel blockers lower blood pressure and open coronary arteries.

Calcium channel blocker benefits: Calcium channel blockers decrease the heart's workload, reduce pressure in the arteries by widening them, and then increase the amount of oxygen delivered to the heart.

Calcium channel blocker risks: Some calcium channel blockers are dangerous for people who have heart failure or had a heart attack.
The most common side effects of calcium channel blockers are fatigue and leg swelling, but side effects vary depending on the specific medication taken. Contact your doctor if you have any of these symptoms. If other medications are prescribed, discuss the risk of any potential medication interactions with your doctor. Since alcohol may cause an excessive drop in blood pressure, it's best to avoid alcohol when taking calcium channel blockers.

Surgical and nonsurgical procedures
Coronary artery bypass grafting (CABG, a surgical procedure) or angioplasty (a nonsurgical procedure) may be recommended if you have CAD or severe or unstable angina (a condition in which the heart muscle is deprived of oxygen, causing chest pain).

Coronary artery bypass graft surgery is open-heart surgery. Before surgery, the blocked area of the coronary arteries is first identified through coronary arteriography (injecting contrast dye into the arteries for X-ray imaging) during cardiac catheterization (passing a special tube into the heart through an artery in the arm or leg). The procedure involves taking a blood vessel from another part of the body or using a synthetic tube to direct blood flow around a coronary artery blockage. Several blood vessels, or "grafts," may be used, depending on the number of blockages.

CABG benefits: CABG improves blood flow to the heart, which decreases or eliminates anginal pain. People who have left coronary artery blockages may get better results with CABG vs. angioplasty. Studies have shown that people who have diabetes fare better with CABG than with percutaneous transluminal coronary angioplasty (PTCA, see below). Newer techniques are available that are less invasive than traditional open-heart surgery.

CABG risks: The recovery time is longer than PTCA. If you're older than age 70, have had the procedure before, or have other major health problems, the risk for complications increases. Common surgical risks include possible anesthesia reactions, bleeding and infection. Rarely, the complications may be fatal.
Angioplasty (also known as percutaneous transluminal coronary angioplasty, PTCA, balloon dilation and balloon angioplasty) is a nonsurgical option. As with CABG, the blocked area of the coronary artery is first identified through coronary arteriography during cardiac catheterization. Then, a small catheter with a balloon at its tip is threaded through a vessel in the groin to the blocked artery in the heart. The balloon is inflated, usually several times, to help widen the artery and then the balloon is removed. Stents (metal mesh tubes that hold vessels open) may be used to help prevent residual and future narrowing in the artery. Long-term medication therapy is typically prescribed. For most people, this involves aspirin and another antiplatelet medication (such as clopidogrel), and a statin (a cholesterol-lowering medication), a beta blocker and an ACE inhibitor.

Angioplasty benefits: Angioplasty can improve blood flow through the coronary arteries. It's less invasive than coronary artery bypass surgery, and the recovery time is faster. General anesthesia can be avoided, and removing a blood vessel from the leg or chest isn't necessary. Angioplasty may be an option for people considering bypass surgery, as well as those who've already had bypass surgery.

Angioplasty risks: About 30 to 40 percent of cleared blockages return within six months. A repeat angioplasty is often successful. The rate of repeat blockages after stent placement may be as low as 15 to 20 percent. It's not as successful in reopening vein grafts used in CABG. A medication-coated stent designed to further reduce a recurrent blockage was approved by the U.S. Food and Drug Administration (FDA) in 2003. Although side effects associated with these stents present a slight risk, original problems with the stents have largely been resolved through the use of medication and meticulous implantation technique. Another medication-coated stent is showing promising results in clinical trials.
Other risks of angioplasty may include:


an allergic reaction to the dye
excessive bleeding that may require treatment or a transfusion
spasm of the coronary artery
damage to the coronary artery that requires emergency bypass surgery
interrupted blood flow to the heart or area where the catheter is inserted, causing a heart attack
stroke
Rarely, complications of angioplasty may be fatal.

Atherectomy is a nonsurgical procedure in which plaque is removed from the arteries. It may be beneficial to insert a stent when removing calcified plaque or for difficult blockages, but research on the long-term benefit doesn't support this.

Other treatments are currently being studied, and new procedures may be considered when conventional methods are unsuccessful, not possible or not tolerated. For example, transmyocardial revascularization is a surgical procedure that users lasers to open tiny holes in the heart muscle to improve blood flow. Other possible treatments include gene therapy and stem-cell injections.

A new noninvasive procedure known as enhanced external counterpulsation (EECP) helps return blood back to the heart through the use of cuffs around the legs that inflate between heartbeats. EECP may help relieve angina as well. It's not appropriate for people who have unstable angina, heart failure and various other medical conditions.


Complications
If left untreated, angina can lead to serious or life-threatening conditions, including:
heart attack and potential cardiac arrest (During a heart attack, there's a critical time period when appropriate treatment can reverse or minimize damage to the heart muscle. The degree of injury and reversibility of heart damage depends on how long the blood flow was blocked.)
congestive heart failure
cardiogenic shock (very low blood pressure due to weak heart pumping)
ventricular dysrhythmia (severe disturbances in heart rhythm)
In severe cases, untreated angina can be fatal.


Pregnancy-specific information
Coronary artery disease is rare in pregnancy. As maternal age increases, however, so can the risk factors associated with CAD. If your doctor suspects you have CAD, a stress echocardiogram may be done.
If you're diagnosed with angina, consult a cardiologist (a heart specialist) who can coordinate care with your primary doctor throughout the pregnancy. The increased demands of pregnancy on your body may aggravate your angina symptoms and pose treatment challenges. Increased blood volume, blood pressure changes, fluid retention and possible pregnancy complications may also influence your heart's stability.

Throughout the pregnancy, your doctor will assess the risk of any angina medications to both you and your baby. Sometimes, the need for medication outweighs inherent risks. If necessary, nitrates and beta blockers may be prescribed to help control your symptoms.


Senior-specific information
Older adults may not have the classic chest pain symptoms of angina. Older women, in particular, typically have more complaints of upper abdominal pain and shortness of breath. In some cases, older adults aren't quick to recognize the severity of their symptoms, which may lead to a delay in care.
Initial treatment involves identifying other treatable illnesses that increase oxygen demand to the heart, such as infection, arrhythmias (irregular heartbeat), thyroid disorders and anemia (a condition marked by a decreased number of red blood cells or hemoglobin, a protein in red blood cells that contains iron).

Medication choice and dose is influenced by:

age-related changes that affect cardiovascular response to medication
increased likelihood for interactions with other medications
how the medication will be absorbed
how long the medication will be effective
how the medication is taken
how the medication is excreted
Older adults may also be more sensitive to medication side effects, particularly a tendency for lightheadedness or dizziness when getting up from a bed or chair (a condition known as orthostatic hypotension).


Considerations
In addition to coronary artery disease, other rare cardiac causes of chest pain may include:
aortic stenosis (narrowing of the aortic valve) or insufficiency
arrhythmia
pericarditis (a painful inflammation of the membrane surrounding the heart)
severe high blood pressure
Prinzmetal's angina
aortic dissection
rarely, cardiomyopathy (any disease affecting the heart muscle)
Remember, significant chest pain of any cause requires a medical evaluation. Remember that chest pain is often be described as pressure, shortness of breath, burning or even gas.


Prevention
Work with your doctor to identify and treat individual risk factors or underlying conditions. Consider the following suggestions to modify your risk of heart disease:
If you smoke, quit.

Exercise regularly, and maintain a normal weight for your age and height.

If you're overweight, ask your doctor for help creating a weight loss plan.

Reduce stress levels.

Avoid excessive alcohol (no more than 2 to 3 ounces a day) and caffeine.

Eat a diet high in fiber and low in fat, cholesterol and sodium.

If you have high cholesterol or high blood pressure, ask your doctor about screening for diabetes.

Ask your doctor about vitamin supplements. Their benefit hasn't been supported in studies, but your doctor may recommend them anyway.