Table of ContentsView AllTable of ContentsTypes of ACSNSTEMI vs. STEMIEmergency TreatmentAfter StabilizationFrequently Asked Questions
Table of ContentsView All
View All
Table of Contents
Types of ACS
NSTEMI vs. STEMI
Emergency Treatment
After Stabilization
Frequently Asked Questions
Many people do not realize that there is more than one form of aheart attack, also known as amyocardial infarction. Some only involve a partial obstruction of blood flow. Heart specialists refer to this type as non-ST-segment elevation myocardial infarction (NSTEMI). NSTEMI is a milder form of heart attack and accounts for around two-thirds of all cases.
This article explains what NSTEMI is and how it differs from a “classic” heart attack. It also describes how NSTEMI is diagnosed and how treatment can vary based on the assessment of a person’s risk factors for a severe heart attack.
Types of Acute Coronary Syndrome
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Recap
Mini Heart Attack: Don’t Doubt Yourself With Suspected Symptoms
A diagnosis of NSTEMI is typically made when the person has symptoms of unstable angina. These include:
Doctors can differentiate STEMI from NSTEMI using anelectrocardiogram (ECG), which records the heart’s electrical activity.
In an ECG, there will typically be a flat line between heartbeats called the “ST segment.” During a classic heart attack, the ST segment will be raised. With NSTEMI, there will be is no evidence of ST-segment elevation.
Because NSTEMI causes damage to the heart muscle, it is still considered a heart attack. Even so, NSTEMI has more in common with unstable angina and usually has better outcomes.
NSTEMI rarely leads to STEMI because they tend to involve different blood vessels. NSTEMI is more likely in people with diffuse coronary disease. This form ofheart diseaseinvolves a network of tiny blood vessels (called collateral vessels) that service the heart only occasionally. By contrast, STEMI will involve the major coronary arteries.
Even so, if NSTEMI involves the partial blockage of a major coronary artery, it can progress to STEMI within hours, weeks, or months if not properly treated.
RecapNSTEMI is differentiated from STEMI using an electrocardiogram (ECG). NSTEMI rarely progresses to STEMI because it tends to affect minor blood vessels servicing the heart.
NSTEMI is differentiated from STEMI using an electrocardiogram (ECG). NSTEMI rarely progresses to STEMI because it tends to affect minor blood vessels servicing the heart.
NSTEMI treatment is identical to that for unstable angina. If you havecardiac symptoms, the emergency medical team will start intensive treatment to stabilize the heart and prevent further damage to the heart muscle.
Stabilization will primarily focus on two things:
Acute Ischemia
The drugs work in different ways:
Oxygen and morphine may be given to improve respiration and reduce pain.
Nitratesare also often used for patients who have continued ischemic pain.
Blood Clot Formation
During NSTEMI, the emergency medical team will provide medications to prevent the formation of blood clots around the site of the obstruction. Doing so prevents a “complete occlusion” in which a vessel is completely blocked.
This may involve medications like aspirin, Plavix (clopidogrel), and other drugs that thin the blood and prevent the clumping of blood cells calledplatelets. Other types of medication, such as enoxaparin, which slows blood clotting, may also be prescribed. This is an important part of the treatment protocol for NSTEMI.
The treatment does not include thrombolytic drugs (“clot busters”) used for STEMI. The drugs are avoided because they often do not help and can lead to a medical emergency known ascardiogenic shock. This occurs when theventricles of the heartfail to pump adequate blood to the body, causing a dangerous drop in blood pressure.
RecapNSTEMI is treated with beta-blockers and statins that improve circulation and prevent further damage to the heart muscle. At the same time, blood thinners like aspirin or Plavix (clopidogrel) are used to prevent blood clots and the complete blockage of the vessel. Other types of medication may also be prescribed.
NSTEMI is treated with beta-blockers and statins that improve circulation and prevent further damage to the heart muscle. At the same time, blood thinners like aspirin or Plavix (clopidogrel) are used to prevent blood clots and the complete blockage of the vessel. Other types of medication may also be prescribed.
How Many People Survive a Heart Attack?
Once a person with NSTEMI is stabilized, the heart specialist, called acardiologist, will assess whether further interventions are needed. Many cardiologists will use a TIMI (thrombosis in myocardial infarction) score to make the determination.
The TIMI score assesses whether the person has any of the following risk factors for a classic heart attack:
If you have two risk factors or less (TIMI score 0-2), you may not need further intervention. If the score is higher, the cardiologist may want to take more aggressive steps.
This includescardiac catheterizationwithangioplastyandstenting. This procedure involves the insertion of a flexible tube (called a catheter) through an artery in the arm or leg to the site of the obstruction. The end of the catheter is then inflated to widen the vessel, after which a narrow length of tubing (called a stent) is left behind to keep the vessel open.
Acardiac stress testmay also be used to determine the need for aggressive treatments. The test measures blood pressure, blood oxygen, and the heart’s electrical activity while you are running on a treadmill or riding a stationary cycle.
RecapOnce a person with NSTEMI is stabilized, the cardiologist may use a TIMI score (which assesses a person’s risk of a severe heart attack) and a cardiac stress test to determine if further treatment is needed.
Once a person with NSTEMI is stabilized, the cardiologist may use a TIMI score (which assesses a person’s risk of a severe heart attack) and a cardiac stress test to determine if further treatment is needed.
How Heart Disease Is Treated
Summary
Non-ST-segment elevated myocardial infarction (NSTEMI) is a type of heart attack in which a minor artery of the heart is completely blocked or a major artery of the heart is partially blocked. It is less serious than a “classic” heart attack, known as an ST-segment elevation myocardial infarction (STEMI).
NSTEMI can cause the same symptoms as STEMI but is generally less damaging to the heart. It is differentiated from STEMI with an electrocardiogram (ECG), which can tell if the electrical activity between heartbeats—called the ST segment—is either elevated or non-elevated.
The treatment of NSTEMI is focused on restoring blood circulation and preventing the formation of blood clots. This typically involves beta-blockers, statin drugs, and blood thinners like aspirin or Plavix (clopidogrel). After the individual is stabilized, the cardiologist will determine if further treatment is needed.
NSTEMI stands for non-ST-segment myocardial infarction. A type of acute coronary syndrome, NSTEMI occurs when blood flow to the heart is suddenly reduced or blocked. NSTEMI is also referred to as a mild heart attack.
Yes, NSTEMI is a type of heart attack that is relatively mild. It occurs when there is a partial obstruction of a major coronary artery or a complete blockage of a minor coronary artery.NSTEMI has the same symptoms as other types of heart attacks—pain or tightness in the chest that may spread to the shoulder or other parts of the upper body, shortness of breath, anxiety, and sweating—but does not cause as much damage to the heart muscle.
Yes, NSTEMI is a type of heart attack that is relatively mild. It occurs when there is a partial obstruction of a major coronary artery or a complete blockage of a minor coronary artery.
NSTEMI has the same symptoms as other types of heart attacks—pain or tightness in the chest that may spread to the shoulder or other parts of the upper body, shortness of breath, anxiety, and sweating—but does not cause as much damage to the heart muscle.
Correction-November 8, 2022:This article was updated to correct the description of unstable angina.
7 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.
Khera S, Kolte D, Aronow WS, et al.Non‐ST‐elevation myocardial infarction in the United States: contemporary trends in incidence, utilization of the early invasive strategy, and in‐hospital outcomes.J Am Heart Assoc. 2014;3(4):e000995. doi:10.1161/JAHA.114.000995
Smith JN, Negrelli JM, Manek MB, Hawes EM, Viera AJ.Diagnosis and management of acute coronary syndrome: an evidence-based update.J Am Board Fam Med. 2015;28(2):283-293. doi:10.3122/jabfm.2015.02.140189
American Heart Association.Unstable Angina.
Amsterdam EA, Wenger NK, Brindis RG, et al.2014 AHA/ACC guideline for the management of patients with non-ST-elevation acute coronary syndromes: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines.Circulation. 2014;130(25):e344-426. doi:10.1161/CIR.0000000000000134
American Heart Association.Cardiac catheterization.
American Heart Association.Exercise stress test.
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