Cochin Cardiac Club

Health Blog by Dr.Uday Nair


What is Unstable angina?

Unstable angina is a pain in your chest that happens if your heart is not getting enough oxygen.

You might have never had chest pain before. Or you might have had a type of chest pain called stable angina. 

Stable angina usually happens when you are active and lasts only a few minutes. It stops when you rest and take your angina medicine.
But unstable angina can happen any time, and may not go away when you take your medicine.

If you get unstable angina, it is an emergency.You should get medical help.

Most people get unstable angina because they have coronary artery disease. Coronary arteries carry blood and oxygen to the heart muscle. Coronary artery disease happens when clumps of fat build up on the lining of a coronary artery. Over time, they make the artery narrower.

If you have unstable angina, a clump of fat in one of your coronary arteries tears open.A blood clot forms over the tear to try to patch it up and partly blocks the artery. Not enough oxygen gets to your heart. This is what causes the pain.The clot may get bigger. If it completely blocks the artery and no oxygen gets to your heart muscle, it's called a heart attack. This can permanently damage your heart.

Risk factors

Risk factors for coronary artery disease include:

  • Being male
  • Diabetes
  • Getting older
  • Family history of coronary heart disease before age 50
  • High blood pressure
  • High LDL cholesterol
  • Low HDL cholesterol
  • Not getting enough exercise
  • Smoking
  • Obesity


Symptoms associated with unstable angina include,
  • Severe and sudden pain the chest with radiating pain to the jaws, neck, arms, shoulder or back
  • A sensation of burning, tightness, chocking and aching in the chest region
  • Pain can occur on rest and is associated with shortness of breath
  • The pain may last for 15 to 25 minutes depending upon the severity


History: In an individual with new onset of chest pain, it is important to distinguish coronary artery disease from other possible causes. A definitive diagnosis often cannot be made immediately. In such cases, angina is presumed until it can be ruled out, due to the seriousness of the diagnosis.

Unstable angina is presumed if the symptoms are described by any of the above criteria. In an individual with previously diagnosed angina, the diagnosis of unstable angina is usually straightforward. The pain is similar in nature, but comes more frequently than before. In cases of prolonged angina at rest that is not relieved by sublingual nitrates, unstable angina may be difficult to differentiate from acute myocardial infarction. 

The doctor will perform a physical examination and check your blood pressure. The doctor may hear abnormal sounds, such as a heart murmur or irregular heartbeat, when listening to your chest with a stethoscope.
Tests to diagnose angina include:
  • Blood tests to check the levels of creatine phosphokinase (CPK),myoglobin, and troponin I and T
  • Coronary angiography
  • ECG
  • Echocardiography
  • Stress tests
    • Exercise or chemically-induced stress test (adenosine, dobutamine)
    • Non-imaging (exercise treadmill) or imaging (nuclear stress test, echo stress test)

  • Treatment

    Your doctor may want you to check into the hospital to get some rest and prevent complications.
    Blood thinners (antiplatelet drugs) are commonly used to treat and prevent unstable angina. Such medicines include aspirin and the prescription drug clopidogrel. The two medicines are often used together. Aspirin (and sometimes clopidogrel) may reduce the chance of heart attack in certain patients.
    During an unstable angina event, you may receive heparin and nitroglycerin. Other treatments may include medicines to control blood pressure, anxiety, abnormal heart rhythms, and cholesterol.
    Some people may need CABG (coronary artery bypass grafting) orangioplasty with stenting. Angioplasty with stenting does not help you live longer than just taking medicine, but it can reduce angina or other symptoms of coronary artery disease. Angioplasty with stenting, however, can be a life-saving procedure if you are having a heart attack.

    Please Note:

    The incidence of unstable angina is growing and nearly one million people receive this diagnosis. Risk of death, myocardial infarction and various complications is due to varied clinical spectrum which is covered by the term unstable angina. Studies show that the incidence of death in the first week after admission is 4% and the incidence of myocardial infarction is 10%. Negative prognostic factors are: old age, left ventricular dysfunction and enlargement of the disease.

    Women with unstable angina are old and have a high prevalence of hypertension, diabetes, congestive heart failure and a family history of heart disease richer than men. Men tend to present high incidence of myocardial infarction and revascularization, increased levels of cardiac enzymes and high rates of diagnostic catheterization and revascularizations. The prognosis is still more dependent on the severity of the disease than sex. The average age of presentation of patients is 62 years. Women are 5 years older than this at diagnosis.

Please read posts-"Heart Attack"and "Emergency Chest Pain"for more information.

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