Unstable Angina

Unstable angina is a heart problem that causes sudden chest pain, often while resting. It’s usually due to reduced blood flow to the heart because of arteries narrowed from fatty deposits. These deposits can rupture, leading to blood clots that can block the flow of blood to the heart.

Unstable angina should be treated as an emergency. If you have new, worsening or persistent chest discomfort, call 911. It could be a heart attack or other serious heart condition.

Causes of Unstable Angina

Blood clots that block an artery cause unstable angina. Typically, the artery will have plaque buildup (atherosclerosis) that has narrowed the blood vessel. The plaque may have damaged areas that make it easier for blood clots to form. Angina can occur each time a clot blocks blood flow in an artery. Learn more about excessive blood clotting.

Symptoms of Unstable Angina

• Unstable angina pain or discomfort:
  • May happen while you’re resting, sleeping or with little physical activity
  • Comes as a surprise
  • May last longer than 15 minutes
  • Usually isn’t relieved by rest or medication
  • May get worse over time
  • Can lead to a heart attack
• Other symptoms include:
  • Shortness of breath
  • Dizziness
  • Anxiety
  • Sweating
  • Nausea and vomiting

To diagnose unstable angina, your health care professional will give you a physical exam and check your blood pressure. They may also do testing, including an EKG, blood tests, echocardiogram or coronary angiogram.

Treatment for Unstable Angina

Your health care team will discuss treatment options with you:

Medications such as:

• Nitrates
• Blood thinners
• Beta blockers
• Cholesterol-lowering medications
• Medications to regulate heart rhythm
• Blood pressure medications

Surgery

• Percutaneous coronary intervention (PCI) may be needed to open a blocked artery. This involves a cardiac catheterization where a catheter with a small balloon is used. The balloon is inflated to open the blockage, then deflated and removed. A stent is often placed to keep the artery open and improve blood flow to the heart.
• Coronary artery bypass graft surgery may be needed if there are severe blockages. In this procedure, a blood vessel is used to bypass the blocked part of the artery, improving blood flow to the heart.

View an illustration of a cardiac catheterization(link opens in new window).

You can help prevent unstable angina by making healthy lifestyle changes, including:

• Eat a healthy diet
• Reach and stay at a healthy weight
• Be physically active
• Quit smoking
• Seek help for substance use disorders

For more information, talk to your health care team.