Unstable Angina

Written by Rachel Nall | Published on September 10, 2012
Medically Reviewed by George Krucik, MD on September 10, 2012

What Is Unstable Angina?

Angina is a condition marked by crushing pain in your chest that may also be felt in your shoulders, neck, and arms. The pain is caused by inadequate blood supply to your heart, which leaves your heart deprived of oxygen.

There are several types of angina; stable angina occurs when you are exerting yourself physically or feeling considerable stress. Stable angina does not typically occur more frequently or worsen over time.

Unstable angina is chest pain that happens suddenly and becomes worse over time. It occurs seemingly without cause—you may be at rest or even asleep. An attack of unstable angina may lead to a heart attack. For this reason, an attack of unstable angina should be treated as an emergency, and you should seek immediate medical treatment.

What Are the Condition’s Symptoms?

The main symptom of angina is chest discomfort/pain, but this sensation can vary from person to person. Sometimes unstable angina causes sensations that feel as if you are having a heart attack.

Angina symptoms include:

  • squeezing or sharp chest pains
  • pain that radiates to extremities and/or back
  • nausea
  • anxiety
  • sweating
  • shortness of breath
  • dizziness
  • unexplained fatigue

If you have been diagnosed with stable angina, it is possible your angina can progress to unstable angina. Be aware of any chest pains you feel even when at rest, chest pains that last longer than yours typically do, or chest pains that simply feel different to you.

If you take nitroglycerin, a medication that enhances blood flow, during a stable angina attack, you may find the medicine does not work during an unstable angina attack.

What Causes the Condition?

Coronary heart disease caused by a buildup of plaque (fatty deposits) along the walls of your arteries (atherosclerosis) is the principal cause of unstable angina. The plaque causes your arteries to narrow and become rigid. That constricts blood flow to your heart. When the heart is deprived of blood and oxygen, you will feel chest pain.

Risk factors for coronary heart disease include:

  • diabetes
  • obesity
  • family history of heart disease
  • high blood pressure
  • high LDL cholesterol
  • low HDL cholesterol
  • being male
  • using any form of tobacco
  • leading a sedentary life

Men 45 and older and women 55 and older are more likely to experience unstable angina.

What Are the Condition’s Effects?

Unstable angina is a signal that your arteries are becoming very narrow and that you could experience a heart attack. If left untreated, your unstable angina can lead to heart attack, heart failure, or arrhythmias (irregular heart rhythm). These can be life-threatening conditions.

How Is the Condition Diagnosed?

You doctor will perform a physical examination that includes checking your blood pressure. He or she may use other tests to confirm unstable angina.

Some tests that may be ordered include:

  • blood tests: to check for enzymes that leak from your heart muscle if it has been damaged
  • ECG: allows your doctor to see patterns in your heartbeats that indicate reduced blood flow
  • echocardiography: uses sound waves to produce images of your heart that your doctor can check for angina-related problems
  • stress tests: causes your heart to work harder and that may make angina easier to detect
  • coronary angiography: uses X-ray imaging to study the health and caliber of your arteries

Because coronary angiography helps your physician visualize any artery narrowing and blockages, it is one of the most common tests used to diagnose unstable angina.

How Is the Condition Treated?

Treatment for unstable angina depends on the severity of your condition. One of the first treatments your physician may recommend is blood thinners such as heparin or clopidogrel. When your blood is not as thick, it can flow more freely through your arteries.

Your doctor may use other medications to reduce angina symptoms, including those to reduce blood pressure, cholesterol, anxiety, or arrhythmias.

If you have a blockage or severe narrowing in an artery, your physician may recommend more invasive procedures. These include angioplasty, where a physician opens up an artery that was previously blocked. Your physician also may insert a small tube known as a stent to keep your artery open.

In severe instances, you may require heart bypass surgery, which reroutes blood flow away from a blocked artery to help improve blood flow to your heart.

Nonmedical treatment options also are often recommended. These include taking steps to lose weight, giving up tobacco use, or exercising more regularly. Taking steps toward a healthier lifestyle can improve your heart health and reduce the risk for future unstable angina episodes.

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