Table of ContentsView AllTable of ContentsSymptomsCausesDiagnosisTreatment
Table of ContentsView All
View All
Table of Contents
Symptoms
Causes
Diagnosis
Treatment
Unstableangina, a form ofacute coronary syndrome (ACS), causes random or unpredictable chest pain as a result of partial blockage of an artery that supplies the heart. In contrast to stable angina, the pain or discomfort of unstable angina often occurs while resting, lasts longer, is not eased with medication, and is unrelated to any obvious trigger, such as physical exertion or emotional stress. Emergency medical attention is necessary.
Verywell / Gary Ferster
Unstable Angina Symptoms
Unstable angina is “unstable” because symptoms may occur more frequently than usual, without any discernible trigger, and may persist for a long time.
The classic symptoms of angina include chest pressure or pain, sometimes squeezing or “heavy” in character, that often radiates to the jaw or left arm.
Keep in mind, though, that many patients with angina do not have classic symptoms. Their discomfort may be very mild and localized to the back, abdomen, shoulders, or either or both arms. Nausea, breathlessness, or merely a feeling ofheartburnmay be the only symptom.
What this means, essentially, is that anyone middle-age or older, especially anyone with one or more risk factors for coronary artery disease, should be alert to symptoms that might represent angina.
In addition, people without any history of coronary artery disease can also develop unstable angina. Unfortunately, these people seem to be at higher risk of amyocardial infarction(heart attack) because they often don’t recognize the symptoms as angina.
Anybody with a history of coronary artery disease should suspect unstable angina if their angina:
If you think there is any possibility you might have unstable angina, you need to go to your healthcare provider or an emergency room immediately.
The ruptured plaque and the blood clot that is almost always associated with the rupture form a partial blockage of the artery. This may create a “stuttering” pattern as the blood clot grows and shrinks, producing angina that comes and goes in an unpredictable fashion.
Unstable angina is so-named because it no longer follows the predictable patterns typical of stable angina. Obviously, such a condition is quite uncertain and, as such, is a medical emergency.
Unstable AnginaSymptoms occur in an unpredictable fashion and without a known trigger.Often occurs at rest and make wake you from sleep.Symptoms can last 30 minutes or more.
Symptoms occur in an unpredictable fashion and without a known trigger.
Often occurs at rest and make wake you from sleep.
Symptoms can last 30 minutes or more.
Symptoms tend to follow a pattern.
Symptoms usually last about 15 minutes.
Stable vs. Unstable Angina: Differences and Similarities
Diagnosis of unstable angina is often done in the emergency room. Symptoms are critically important in making the diagnosis of unstable angina, or indeed, any form of ACS.
In particular, if you have one or more of the following three symptoms, your healthcare provider should take that as a strong clue that a type of ACS is occurring:
Once your healthcare provider suspects ACS, they should immediately order anelectrocardiogram (ECG)andcardiac enzymetesting. High-sensitivity cardiac troponins are the preferred biomarker to detect or exclude myocardial injury (heart cell damage).
The results of these tests, together with review of your symptoms, will help confirm a diagnosis.
Notably, unstable angina andnon-ST-elevation myocardial infarction (NSTEMI), a type of heart attack, are similar conditions. In each condition, a plaque rupture has occurred in a coronary artery, but the artery is not completely blocked so at least someblood flowremains.
In both of these conditions, the symptoms of unstable angina are present. The only difference is that in an NSTEMI, enough heart cell damage has occurred to produce an increase in cardiac enzymes.
ST SegmentsCardiac EnzymesDiagnosisElevatedElevated"Large" myocardial infarction (MI), a.k.a. an ST-segment elevation MI orSTEMINot elevatedElevated"Smaller" MI, a.k.a. a non-ST segment MI orNSTEMINot elevatedNot elevatedUnstable anginaTreatmentIf you have unstable angina, you will be treated with one of two general approaches:Treated aggressively with medicationsto stabilize the condition, then evaluated non-invasivelyTreated aggressively with medications to stabilize the condition and given an early invasive intervention (generally, angioplasty and stenting).Since unstable angina and NSTEMI are so similar, their treatment is identical.Stable vs. Unstable Angina: Differences and SimilaritiesMedicationsMedications are used to ease chest pain and associated ischemia (when the heart is not obtaining adequate blood flow). Medications to stop blood clot formation within the affected artery are also given.There are three main types of medications used to treat unstable angina: anti-ischemics, antiplatelets, and anticoagulants.Anti-Ischemic TherapySublingual nitroglycerin, an anti-ischemic medication, is often given to alleviate any ischemic chest pain.For persistent pain, intravenous (through the vein) nitroglycerin may be given, assuming there are no contraindications (for example, low blood pressure). Morphine may also be given for persistent pain.Abeta-blocker, another anti-ischemic medication, will also be given as long as there are no contraindications, such as signs of heart failure. This can lower blood pressure and heart rate, both of which, when high, increase the heart’s oxygen consumption requirements.Finally, a cholesterol-lowering medication called astatin, like Lipitor (atorvastatin) or Crestor (rosuvastatin), will be given. These drugs have been found to decrease the rate of heart attacks, death from coronary heart disease, need for myocardial revascularization, and stroke.Antiplatelet TherapyAntiplatelet medications, which prevent platelet clumping, will be given as well. This includes bothaspirinand aplatelet P2Y12 receptor blocker—either Plavix (clopidogrel) or Brilinita (ticagrelor).Anticoagulant TherapyAnticoagulants thin the blood. Examples include unfractionated heparin (UFH) and Lovenox (enoxaparin).Three Types of Acute Coronary Syndrome (ACS) to UnderstandPossible Invasive InterventionOnce stabilized with medication, a cardiologist will decide whether a patient needs an invasive intervention, usuallyangioplasty with stenting(a.k.a. percutaneous coronary intervention, or PCI). This procedure involves the use of a balloon catheter to unblock the artery and the subsequent placement of a stent to prop the artery open.Angioplasty Surgery: Everything You Need to KnowDetermining whether to proceed with angioplasty and stenting is a very important decision. One tool many cardiologists use to help guide this decision is called thethrombolysis in myocardial infarction (TIMI) score.The TIMI score is based on the following risk factors:Age 65 years or olderPresence of at least three risk factors forcoronary heart disease(hypertension, diabetes,dyslipidemia, smoking, or a positive family history of an early myocardial infarction)Prior coronary artery blockage of 50% or moreAt least two episodes of angina in the last 24 hoursElevated cardiac enzymesUse of aspirin in the last seven daysAlow TIMI score (0 to 1)indicates a 4.7% chance of having an adverse heart-related outcome (for instance, death, heart attack, or severe ischemia requiring revascularization).Ahigh TIMI score (6 to 7)indicates a 40.9% chance of having an adverse heart-related outcome and, thus, nearly always warrants an early intervention like PCI.A Word From VerywellIf you are experiencing new or worsening chest pain or chest pain that will not go away with rest or medication, you need to go to the emergency room right away. Even if your pain turns out to not be heart-related, it’s much better to be cautious and get evaluated.
“Smaller” MI, a.k.a. a non-ST segment MI orNSTEMI
If you have unstable angina, you will be treated with one of two general approaches:
Since unstable angina and NSTEMI are so similar, their treatment is identical.
Medications
Medications are used to ease chest pain and associated ischemia (when the heart is not obtaining adequate blood flow). Medications to stop blood clot formation within the affected artery are also given.
There are three main types of medications used to treat unstable angina: anti-ischemics, antiplatelets, and anticoagulants.
Anti-Ischemic Therapy
Sublingual nitroglycerin, an anti-ischemic medication, is often given to alleviate any ischemic chest pain.
For persistent pain, intravenous (through the vein) nitroglycerin may be given, assuming there are no contraindications (for example, low blood pressure). Morphine may also be given for persistent pain.
Abeta-blocker, another anti-ischemic medication, will also be given as long as there are no contraindications, such as signs of heart failure. This can lower blood pressure and heart rate, both of which, when high, increase the heart’s oxygen consumption requirements.
Finally, a cholesterol-lowering medication called astatin, like Lipitor (atorvastatin) or Crestor (rosuvastatin), will be given. These drugs have been found to decrease the rate of heart attacks, death from coronary heart disease, need for myocardial revascularization, and stroke.
Antiplatelet Therapy
Antiplatelet medications, which prevent platelet clumping, will be given as well. This includes bothaspirinand aplatelet P2Y12 receptor blocker—either Plavix (clopidogrel) or Brilinita (ticagrelor).
Anticoagulant Therapy
Anticoagulants thin the blood. Examples include unfractionated heparin (UFH) and Lovenox (enoxaparin).
Three Types of Acute Coronary Syndrome (ACS) to Understand
Possible Invasive Intervention
Once stabilized with medication, a cardiologist will decide whether a patient needs an invasive intervention, usuallyangioplasty with stenting(a.k.a. percutaneous coronary intervention, or PCI). This procedure involves the use of a balloon catheter to unblock the artery and the subsequent placement of a stent to prop the artery open.
Angioplasty Surgery: Everything You Need to Know
Determining whether to proceed with angioplasty and stenting is a very important decision. One tool many cardiologists use to help guide this decision is called thethrombolysis in myocardial infarction (TIMI) score.
The TIMI score is based on the following risk factors:
Alow TIMI score (0 to 1)indicates a 4.7% chance of having an adverse heart-related outcome (for instance, death, heart attack, or severe ischemia requiring revascularization).
Ahigh TIMI score (6 to 7)indicates a 40.9% chance of having an adverse heart-related outcome and, thus, nearly always warrants an early intervention like PCI.
A Word From Verywell
If you are experiencing new or worsening chest pain or chest pain that will not go away with rest or medication, you need to go to the emergency room right away. Even if your pain turns out to not be heart-related, it’s much better to be cautious and get evaluated.
4 SourcesVerywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Amsterdam EA, Wenger NK, Brindis RG, et al.2014 AHA/ACC guideline for the management of patients with non-ST-elevation acute coronary syndromes.J Am Coll Cardiol. 2014;64(24):e139-e228. doi:10.1016/j.jacc.2014.09.017Hamm CW, Braunwald E.A classification of unstable angina revisited.Circulation. 2000;102(1):118-22. doi:10.1161/01.CIR.102.1.118Gulati M, Levy PD, Mukherjee D, et al.2021 AHA/ACC/ASE/CHEST/SAEM/SCCT/SCMR guideline for the evaluation and diagnosis of chest pain: a report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines.Circulation. 2021;144(22). doi:10.1161/CIR.0000000000001029Antman EM et al.The TIMI risk score for unstable angina/non-ST elevation MI: A method for prognostication and therapeutic decision making.JAMA. 2000;284(7):835-42. doi:10.1001/jama.284.7.835Additional ReadingMeier MA, Al-Badr WH, Cooper JV, et al.The new definition of myocardial infarction: diagnostic and prognostic implications in patients with acute coronary syndromes.Arch Intern Med. 2002;162(14):1585-9. doi:10.1001/archinte.162.14.1585
4 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Amsterdam EA, Wenger NK, Brindis RG, et al.2014 AHA/ACC guideline for the management of patients with non-ST-elevation acute coronary syndromes.J Am Coll Cardiol. 2014;64(24):e139-e228. doi:10.1016/j.jacc.2014.09.017Hamm CW, Braunwald E.A classification of unstable angina revisited.Circulation. 2000;102(1):118-22. doi:10.1161/01.CIR.102.1.118Gulati M, Levy PD, Mukherjee D, et al.2021 AHA/ACC/ASE/CHEST/SAEM/SCCT/SCMR guideline for the evaluation and diagnosis of chest pain: a report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines.Circulation. 2021;144(22). doi:10.1161/CIR.0000000000001029Antman EM et al.The TIMI risk score for unstable angina/non-ST elevation MI: A method for prognostication and therapeutic decision making.JAMA. 2000;284(7):835-42. doi:10.1001/jama.284.7.835Additional ReadingMeier MA, Al-Badr WH, Cooper JV, et al.The new definition of myocardial infarction: diagnostic and prognostic implications in patients with acute coronary syndromes.Arch Intern Med. 2002;162(14):1585-9. doi:10.1001/archinte.162.14.1585
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
Amsterdam EA, Wenger NK, Brindis RG, et al.2014 AHA/ACC guideline for the management of patients with non-ST-elevation acute coronary syndromes.J Am Coll Cardiol. 2014;64(24):e139-e228. doi:10.1016/j.jacc.2014.09.017Hamm CW, Braunwald E.A classification of unstable angina revisited.Circulation. 2000;102(1):118-22. doi:10.1161/01.CIR.102.1.118Gulati M, Levy PD, Mukherjee D, et al.2021 AHA/ACC/ASE/CHEST/SAEM/SCCT/SCMR guideline for the evaluation and diagnosis of chest pain: a report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines.Circulation. 2021;144(22). doi:10.1161/CIR.0000000000001029Antman EM et al.The TIMI risk score for unstable angina/non-ST elevation MI: A method for prognostication and therapeutic decision making.JAMA. 2000;284(7):835-42. doi:10.1001/jama.284.7.835
Amsterdam EA, Wenger NK, Brindis RG, et al.2014 AHA/ACC guideline for the management of patients with non-ST-elevation acute coronary syndromes.J Am Coll Cardiol. 2014;64(24):e139-e228. doi:10.1016/j.jacc.2014.09.017
Hamm CW, Braunwald E.A classification of unstable angina revisited.Circulation. 2000;102(1):118-22. doi:10.1161/01.CIR.102.1.118
Gulati M, Levy PD, Mukherjee D, et al.2021 AHA/ACC/ASE/CHEST/SAEM/SCCT/SCMR guideline for the evaluation and diagnosis of chest pain: a report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines.Circulation. 2021;144(22). doi:10.1161/CIR.0000000000001029
Antman EM et al.The TIMI risk score for unstable angina/non-ST elevation MI: A method for prognostication and therapeutic decision making.JAMA. 2000;284(7):835-42. doi:10.1001/jama.284.7.835
Meier MA, Al-Badr WH, Cooper JV, et al.The new definition of myocardial infarction: diagnostic and prognostic implications in patients with acute coronary syndromes.Arch Intern Med. 2002;162(14):1585-9. doi:10.1001/archinte.162.14.1585
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