Unstable and Stable Angina

There are two different kinds of angina. Stable angina occurs due to a fixed or stable obstruction of blood supply in one or more of the coronary arteries. Unstable angina refers to angina that is less predictable and doesn’t appear to be tied to what you are doing at the time of the attack. In these cases angina can occur even when you are resting or asleep. Many of these cases of angina are due to blood clots forming in the coronary arteries. Unstable angina also refers to angina that cannot be controlled by medication. When angina does not respond to medication, hospitalization may be necessary.

The diagnosis of angina is usually made by your doctor after discussing with you:

  • your symptoms
  • test results

Helpful tests may include:

  • an ECG
  • a graded exercise test
  • a stress mibi or thallium scan
  • a stress echocardiogram
  • coronary angiography

The correct test or combination of tests varies from individual to individual. Your doctor can discuss with you the relative merits of these tests and help you have the most appropriate study.

Medications for Angina Pectoris

Treatment for angina usually involves medications that affect either the supply of blood to the heart muscle or the heart’s demand for oxygen. Drugs that affect the supply of blood to the heart muscle include vasodilators, nitrate compounds and calcium channel blockers. Beta blockers are drugs that reduce the demand of the heart muscles for oxygen. Effective treatment for people with severe angina often involves using a combination of medications. Invasive techniques (procedures that involve entering the body) that improve the blood supply to the heart may also be used to treat angina. These include angiography, angioplasty and bypass surgery.

Lifestyle Changes

Changes in lifestyle are often required when angina develops. A healthier lifestyle which includes:

  • Avoid smoking
  • Weight loss
  • Regular exercise
  • Healthy Diet and avoid large meals
  • Rarely adjustments in activities are required

Medications to treat angina act primarily in one of two ways. Some medications try to improve the blood supply to the heart muscle. There agents are known as coronary. These drugs cause the coronary vessels to relax. When this happens, the diameter of the blood vessel or lumen gets bigger, allowing more blood through. Other medications act on the heart to reduce its demand for oxygen by controlling the heart rate and the power of each heart contraction. Some of the agents used to treat angina both increase the blood supply to the heart muscle and reduce the demand of heart muscle for blood and oxygen In addition many cardiac medications used to treat angina may have other roles and are often used to treat other conditions such as high blood pressure.

The common classes of agents used in the treatment of angina are:

  • Nitrate compounds are a class of drugs commonly used to dilate the blood vessels: the best known is nitroglycerin. Nitrates relax both the veins (reducing the amount of blood that returns to the ventricles of the heart and thus lessening the work of pumping) and the coronary arteries (increasing the blood supply to the heart muscle).
  • Calcium channel blockers (eg Norvasc) work by blocking the constriction of the arteries, thus keeping the vessels dilated (open) and improving blood flow. They are often prescribed as an addition to a regimen consisting of a beta blocker and a nitrate.
  • Beta blockers were introduced during the early 1970s, and are now commonly used to treat coronary artery disease. They work by blocking or inhibiting certain adrenaline receptors in the heart, thereby reducing the demand of the heart muscle for oxygen during physical activity or excitement. Beta blockers also help to lower blood pressure, which further reduces the work of the heart.

Effective treatment for people with severe angina often involves using a combination of drugs, such as a nitrate, a beta blocker, and a calcium channel blocker.

Other Treatment

Your doctor may need more information about the status of the blood supply of your heart. This is commonly provided achieved by Angiography, which involves using x-rays to record the passage of a contrast dye in the heart. Angiography enables doctors to see any problems in blood flow in the coronary arteries, such as atherosclerosis (“hardening of the arteries”), regurgitation or pooling of blood in a chamber because of heart valve or muscle malfunction. Depending on the results of the angiogram, your doctor may advise other invasive techniques (procedures that involve entering the body) that may improve the blood supply to the heart. One of these is percutaneous transluminal coronary angioplasty. This procedures is also known as PTCA, angioplasty, balloon dilation, or balloon angioplasty. Angioplasty is not a form of open heart surgery, but uses a catheter to re-open a narrow artery. Another invasive procedure that can reduce or eliminate angina is coronary artery bypass surgery.