The most common cause is coronary artery disease. A less common cause of angina is spasm of the coronary arteries. 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. When the coronary arteries are narrowed by more than 50 to 70%, they can not 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).

Angina is usually felt as a squeezing, pressure, heaviness, tightening, or aching across the chest, particularly behind the breastbone.

Other characteristic symptoms of angina include:

• Pain that radiates to the neck, jaw, arms, back or even teeth.
  
• Indigestion, heartburn, weakness, sweating, nausea, cramping and shortness of breath
  
• Many times angina symptoms occur after a heavy meal, during exertion or severe emotional stress
  
• Angina typically lasts 1 to 15 minutes and is relieved by rest or by placing a nitroglycerin tablet under the tongue. Resting and nitroglycerin decrease the heart muscle's demand for oxygen, thus relieving angina.

IMPORTANT NOTE: Angina is usually a warning sign of the presence of significant coronary artery disease. Patients with angina are at risk of developing a heart attack (myocardial infarction).

A complete history and physical are a normal part of a chest pain workup for angina. Many times the history can strongly suggest angina. A resting EKG is usually not very helpful in angina patients, since the chest pain and lack of oxygen supply to the heart only become evident during exertion or excitement.

Lab Studies

Exercise treadmill

During an exercise treadmill test, EKG recordings of the heart are performed continuously as the patient undergoes increasing levels of exercise. The occurrence of chest pain during exercise can be correlated with changes on the EKG, which demonstrate the lack of oxygen to the heart muscle. When the patient rests, the angina and the changes on the EKG, which indicate lack of oxygen to the heart, can both disappear. Accuracy of this test is between 60 to 70%.
(See this link for an overview of exercise treadmill testing: http://www.yourhealth.com/bin/build_result_doc.pl?SEARCHTERM=cardiac+stress+tests+&page=/ahl/1532.html)

Thallium stress test

A nuclear agent (thallium) is given intravenously during an exercise treadmill test. The addition of thallium allows nuclear imaging of blood flow to different regions of the heart, using an external camera. If reduced blood flow in an area of the heart is present during exercise with normal blood flow to other parts of the heart, this signifies significant artery narrowing in that region of the heart.
(See this link for an overview of thallium treadmill testing: http://www.americanheart.org/Heart_and_Stroke_A_Z_Guide/thallium.html)

Stress Echocardiography

This test combines echocardiography (ultrasound imaging of the heart muscle) with exercise treadmill testing. Areas of blockage of the coronary arteries can be detected as abnormalities in muscle contraction of the heart. Both stress echocardiography and thallium stress tests are both about 80 to 85% accurate in detecting significant coronary artery disease.
(See this link for an overview of stress-echo treadmill testing: http://www.auhs.edu/continuing/cme/medicine/v1n1/introduction_frame.htm)

Cardiac Catheterization with Angiography

This is a technique that allows x-ray pictures to be taken of the coronary arteries. It is the most accurate test to detect coronary artery narrowing. Coronary arteriography gives a picture of the location and severity of coronary artery disease.
(See this link for an overview of cardiac catheterization: http://www.vh.org/Patients/IHB/IntMed/Cardio/Cath/Intro.html)

Treatment options include rest, medications (nitroglycerin, beta-blockers, calcium channel blockers), percutaneous transluminal coronary angioplasty (PTCA), or coronary artery bypass graft surgery (CABG).

Resting, sublingual (placed under the tongue) nitroglycerin tablets, and nitroglycerin sprays all relieve angina by reducing the heart muscle's demand for oxygen. Nitroglycerin also relieves spasm of the coronary arteries and can redistribute coronary artery blood flow to areas that need it most. Short-acting nitroglycerin can also be used before exertion to prevent angina.

Longer-acting nitroglycerin preparations, such as Isordil tablets, Nitro-Dur transdermal systems (patch form) and Nitrol ointment are useful in preventing and reducing the frequency and intensity of episodes in patients with chronic angina. Headaches and lightheadedness due to excess lowering of blood pressure can limit the use of nitroglycerin preparations.

Beta-blockers relieve angina by inhibiting the effect of adrenaline on the heart. Inhibiting adrenaline decreases the heart rate, lowers the blood pressure, and reduces the pumping force of the heart muscle, all of which reduce the heart muscle's demand for oxygen. Examples of beta-blockers include propranolol (Inderal), metoprolol (Lopressor), and atenolol (Tenormin). Side effects include worsening of asthma, excess lowering of the heart rate and blood pressure, depression, fatigue, impotence, increased cholesterol levels, and shortness of breath due to diminished heart muscle function.

Calcium channel blockers relieve angina by lowering blood pressure, and reducing the pumping force of the heart muscle, thereby reducing muscle oxygen demand. Calcium channel blockers also relieve coronary artery spasm. Examples of calcium channel blockers include nifedipine (Procardia), verapamil (Calan), and diltiazem (Cardiazem). Verapamil and diltiazem also lower the heart rate. Side effects include swelling of the legs, excess lowering of the heart rate and blood pressure, and depressing heart muscle function, thereby causing an increased shortness of breath.

IMPORTANT NOTE: When patients continue to have angina despite maximally tolerated combinations of nitroglycerin medications, beta-blockers and calcium-blockers, cardiac catheterization with coronary arteriography is indicated. Depending on the location and severity of the disease in the coronary arteries, patients can be referred for balloon angioplasty (percutaneous transluminal coronary angioplasty or PTCA) or coronary artery bypass graft surgery (CABG) to increase coronary artery blood flow.

A client with a history of angina presents underwriting problems for the life insurance carrier. In many cases these clients are declined for individual coverage. However, there are clients with a history of angina who are insurable based on a "favorable" risk factor profile. The following questions will allow you to quickly screen any client with a history of angina:

1) Does the client currently smoke?

Underwriting Comment: Clients who have a history of angina and continue to smoke may not be insurable for individual coverage. Smoking is a major risk factor for heart disease and one that can have a dramatic impact on outcome (i.e. life expectancy). The good news is that clients who have angina and quit smoking have better survival rates and better pricing for life insurance.

2) When was the client first diagnosed with angina and have the symptoms remained stable?

Underwriting Comment: There are basically two kinds of angina: stable and unstable. Stable angina is usually related to physical effort (i.e. walking up a hill or stairs), stable and managed by medications and lifestyle changes. Clients with stable angina are insurable. Unstable angina is not related to effort (i.e. chest pain at rest), is unstable (i.e. progressively worse despite medications) and usually signals the onset of a cardiac event (i.e. heart attack, coronary angioplasty, coronary bypass). Clients with unstable angina are uninsurable for individual coverage.

3) What medications is the client taking?

Underwriting Comment: Stable angina can be managed by a variety of medications. Beta blockers (i.e. Tenormin), calcium channel blockers (i.e. Cardizem) and nitroglycerin preparations (i.e. Isordil, Imdur) are all used to manage chest pain. Unstable angina may require more frequent use of nitroglyercin preparations (i.e. Nitrostat, Nitropaste, Minitran, etc.).

4) Does the client have any history of other cardiac problems?

Underwriting Comment: Angina superimposed on other forms of cardiac disease almost universally renders the client uninsurable for individual coverage. Clients who have had a heart attack, coronary angioplasty, or coronary bypass surgery and go on to have angina on not insurable on an individual basis.

5) Is the client currently involved in any form of cardiac rehabilitation or undergone any lifestyle changes?

Underwriting Comment: Lifestyle changes such as quitting smoking, exercise, diet, and stress reduction are major components to the successful management of angina. They are also major components in the final risk analysis.

Featured Topic in August 2001 Newsletter:

Abdominal Aortic Aneurysm (AAA)