Heart Attack and Unstable Angina

By Dr. Birnstiel

Although an episode of angina may seem similar to a heart attack, there is a difference. In an angina episode, the heart muscle suffers from a temporary lack of oxygen. In a heart attack, part of the heart muscle dies from lack of oxygen. Angina is called stable when the symptoms and circumstances triggering the episodes are known, the episode is not uncommon for the patient and the symptoms pass quickly with rest or medication. Nearly all other angina episodes are called unstable angina and require emergency treatment since they may be the last warning before the heart attack starts.

If rest or angina medication does not alleviate the symptoms within five minutes, call for emergency help immediately. Death or permanent damage caused by a heart attack is frequently due to fear of embarrassment, shyness or denial – any of which may cause a patient to hope for two hours (or more) that the symptoms will just go away.

Cause and Risk Factors

Angina and heart attacks occur when the heart muscle does not receive enough oxygen because it does not receive enough blood. In most but not all cases this is because of cholesterol plaques in the coronary arteries. For unknown reasons, these plaques can rupture, which may cause a blood clot to form. A blood clot can cause an acute blockage of the artery. When the heart muscle cells that depend on the blocked artery start to die, the episode of angina is then considered to be a heart attack.

Risk factors for angina and heart attacks include:

1) Previous problems with heart disease

2) Age – heart attacks occur more frequently in men older than 45 and in women older than 55

3) A family history of heart disease before age 55

4) Smoking

5) High cholesterol levels

6) High blood pressure

7) Diabetes

8) Lack of physical activity

9) Being overweight

Symptoms

The symptoms of angina or a heart attack vary in each case. They may just feel like indigestion, or there may be no symptoms at all (a “silent” heart attack). More typically, the symptoms consist of:

1) Chest pain or discomfort

2) Pain radiates into other parts of the upper body (shoulders, arms, throat, neck or back)

3) Shortness of breath

4) Nausea, dizziness, weakness and cold sweat.

Diagnosis

Diagnostic tests include:

1) blood tests for “markers” given off by dying heart muscle cells

2) an electrocardiogram, testing for abnormal electrical activity of the heart

3) a nuclear scan, testing if all areas of the heart are supplied with blood

4) a coronary arteriography (also called angiography) to test for blockages and narrowed passages in the coronary arteries

Treatment

Some common treatments and medications for angina and heart attack patients include:

1) Surgical procedures (such as coronary angioplasty to widen a narrowed passage, or bypass surgery to replace a narrowed artery)

2) Nitroglycerin to acutely widen arteries in an angina episode – this effect is quite dramatic – the patient needs to sit down first

3) Blood-pressure drugs (beta blockers, calcium antagonists and ACE inhibitors) for a more gentle, longer-lasting widening of blood vessels

4) Aspirin to prevent the formation of blood clots

5) Other medications such as digitalis to enhance heart pumping action, cholesterol-lowering drugs to reduce plaque formation, and diuretics

6) Elimination of risk factors (see above) as much as possible

 It is also important to work with a doctor on an emergency plan. Once a heart attack occurs, a lot of patients tend to deny the symptoms and refuse to get emergency aid. Therefore, tell friends and family to call on your behalf if they think you are having a heart attack – even if you don’t want them to. Once a heart attack has occurred, time is of essence for treatment with thrombolytic drugs to “bust” the blood clot and restore blood flow. These drugs need to be given within one hour after symptoms begin to be most effective.