A non-ST-elevation myocardial infarction (NSTEMI) is a type of heart attack. It causes a partial or incomplete blockage of one of the body’s coronary arteries, reducing blood flow to the heart.

This can damage the heart and disrupt its ability to pump blood throughout the body.

The damage to the heart from an NSTEMI is less serious than that of a STEMI. However, any heart attack can be fatal, cause lasting damage to the heart, and increase the risk of subsequent heart problems.

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A STEMI is a more serious heart attack than an NSTEMI. This is because a STEMI causes a larger blockage of one or more coronary arteries and deprives the heart of blood. This can cause more long-term heart health problems and increases the risk of death in the short term.

An EKG is a test that healthcare professionals use to measure the heart’s electrical activity. Both NSTEMI and STEMI change electrical activity in the heart, but they do so in different ways.

An EKG reading indicating that an NSTEMI has occurred will usually show the coronary artery only partially blocked. In contrast, if a person has had a STEMI, the EKG will usually show a complete blockage in the coronary artery.

ST waves show the heart’s contraction pattern when it pushes blood out of the ventricles, which are two heart chambers. Changes in these waves correspond to the type of damage a heart attack has caused.

While doctors typically consider an NSTEMI less serious, newer research suggests that long-term outcomes may be similar and perhaps even slightly worse with this type of cardiac event. For example, a 2021 study found that 24.7% of people who had NSTEMIs died within 5 years, compared to 21.4% of those who had STEMIs. The death rates 6 months following the heart attack were similar between the two groups.

Unstable angina is a type of chest pain. Doctors class it as an acute coronary syndrome that occurs when blood flow to the heart decreases, which may cause a heart attack. It differs from stable angina, which can occur more frequently and without exertion.

Unstable angina and NSTEMI are initially difficult to tell apart, and doctors usually require a blood test to help with diagnosis. Additionally, a person cannot rule out a heart attack according to symptoms alone, so they should treat any symptom as a medical emergency, even if they have had symptoms before without having a heart attack.

Symptoms of unstable angina can feel similar to NSTEMI and may include:

  • chest pain that can occur when resting, sleeping, and without exertion
  • shortness of breath, often without exertion
  • unexpected chest pain
  • episodes of pain lasting longer than stable angina that may worsen over time
  • chest pain that medication or rest does not relieve
  • stomach pain or indigestion
  • fainting or dizziness

NSTEMI symptoms are important to recognize. A person should call 911 immediately if they experience any of them.

The following are symptoms of an NSTEMI:

  • feeling short of breath
  • pressure, tightness, or discomfort in the chest
  • pain or tightness in the jaw, neck, back, or stomach
  • dizziness or a feeling of lightheadedness
  • nausea
  • excessive sweating

The likelihood of a person having an NSTEMI or any type of heart attack increases with these risk factors:

  • smoking
  • advancing age
  • being male
  • a family history of coronary artery disease
  • a personal history of coronary artery disease or heart attack
  • diabetes
  • renal insufficiency
  • high blood pressure
  • high cholesterol
  • having obesity
  • eating a diet high in saturated and trans fats
  • excessive alcohol consumption

Certain people are more likely to have atypical NSTEMI symptoms, such as stomach pain. They include:

  • women
  • people over the age of 75 years
  • people with diabetes
  • individuals with dementia
  • people with renal insufficiency

Following an NSTEMI, a blood test will show higher than expected levels of troponin I or troponin T.

The heart releases these chemicals following an injury, and they signify damage to the organ. In comparison with STEMI, the damage from an NSTEMI is usually less severe.

While blood tests are a good indication of whether a heart attack has occurred and the degree of damage, only an ECG can reliably diagnose the type of heart attack. An ECG shows the patterns of ST segments, which a doctor can measure and analyze.

ST segments show the period of contraction when the heart pushes blood out of the ventricles. Changes in these segments can help with diagnosing the type of heart damage.

Treatment for an NSTEMI depends on how blocked the coronary artery is and the severity of the heart attack itself.

To determine this, a person’s doctor will assign them a Global Registry of Acute Coronary Events (GRACE) score, which measures whether they are low, medium, or high risk.

To find an individual’s GRACE score, a doctor will look at factors that include:

  • a person’s age
  • their systolic blood pressure
  • their heart rate or heartbeat
  • whether they have raised serum creatinine levels
  • whether there was a cardiac arrest on hospital admission
  • ST-segment deviation in their EKG
  • elevated cardiac markers
  • a person’s Killip class, or signs of heart failure from a physical exam

If the GRACE score indicates a person has a low risk after an NSTEMI, a doctor may prescribe medication.

Drugs that a doctor may prescribe include:

  • anticoagulants
  • antiplatelets
  • beta-blockers
  • nitrates
  • statins
  • angiotensin-converting-enzyme inhibitors
  • angiotensin receptor blockers

For medium-to-high risk individuals, a doctor may recommend a percutaneous coronary intervention or a coronary artery bypass graft.


There are ways to reduce the chances of having an NSTEMI and improve overall heart health.

They include:

  • consuming a nutritious and balanced diet, including fruits, vegetables, healthy fats, and whole grains
  • reducing and limiting foods that are high in saturated and trans fats
  • exercising at least 30 minutes, five times a week
  • managing stress levels
  • quitting a smoking
  • maintaining a moderate weight

If a person has diabetes, high cholesterol, or high blood pressure, it is essential to manage these conditions adequately. Not doing so could increase the risk of a heart attack.

If healthcare professionals believe a person is at risk of having a heart attack, the individual should take precautions.

They should ensure emergency contact numbers and a list of current medications and allergens are to hand whenever they are heading out or going away in case of a heart attack.

Heart attacks are often frightening. They can be fatal and cause long-term health consequences, including a reduced lifespan. This applies to an NSTEMI, even though it is a less severe type of heart attack than a STEMI. Medication and surgery may help treat an NSTEMI.

By addressing lifestyle factors, such as diet and exercise, and carefully managing any conditions that might increase the risk of an NSTEMI, a person can significantly lower the likelihood of one occurring.