NSTEMI or non-ST segment elevation myocardial infarction is a type of heart attack. An NSTEMI differs from a STEMI, which is the most common type of heart attack, by causing less damage to a person's heart.
An electrocardiogram or ECG that displays each heartbeat as a waveform is used to determine if an NSTEMI or a STEMI has occurred in a person. When looking at the waveforms of a person who has had an NSTEMI, they appear very distinct from those of someone who has had a STEMI.
The damage to the heart from an NSTEMI is less serious than that from a STEMI. However, any heart attack can be very frightening.
Fast facts on NSTEMI:
- A person who has had any heart attack is said to have acute coronary syndrome.
- A doctor will take a blood test and do an ECG if they suspect an NSTEMI.
- The severity of any heart attack determines the type of treatment that is given.
Treatment for an NSTEMI depends on how blocked the coronary artery is, as well as the severity of the heart attack itself.
To determine this, a person will be given a GRACE score, which will decide if they are low, medium, or high risk.
To find a person's GRACE score, a doctor will look at factors that include:
- the age of the person
- their systolic blood pressure
- their heart rate or heartbeat
- whether their serum creatinine level is raised
- whether there was a cardiac arrest on hospital admission
- ST-segment deviation in their ECG
- elevated cardiac marker
- Killip class, or signs of heart failure from a physical exam
If the GRACE score indicates a person is a low risk after an NSTEMI, a doctor may prescribe medication.
Drugs that are commonly given include:
- angiotensin-converting-enzyme (ACE) inhibitors
- angiotensin receptor blockers (ARBs)
For those that are considered medium to high risk, a percutaneous coronary intervention or PCI, or a coronary artery bypass graft or CABG may be performed.
There are ways to reduce the chances of having an NSTEMI and improving overall heart health.
Steps people can take to reduce their risk of an NSTEMI include:
- having a healthy, 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 regularly, recommended as at least 30 minutes five times a week
- managing stress levels
- quitting a smoking habit
- remaining at a healthy weight
If a person is deemed to be at risk of having a heart attack, it is advisable for them to take precautions so that they are prepared.
They should ensure emergency contact numbers, a list of current medications and any allergens are to hand whenever they are heading out or going away, in case a heart attack occurs.
Symptoms of an NSTEMI 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
- experiencing nausea
- excessive sweating
If an NSTEMI has occurred, a blood test will show higher than normal levels of creatinine kinase-myocardial band (CK-MB), troponin I, and troponin T.
If found, these indicate that damage to the heart cells has happened, though this will be less severe than in the case of a STEMI.
While blood tests are a good indication of whether a heart attack has occurred, an ECG must still be carried out. This will show the patterns of ST segments, which can then be measured and analyzed. ST segments show the area of damage that has been done to the heart.
An ECG in the case of an NSTEMI will show:
- a depressed ST segment or T-wave inversion
- no progression to Q wave
- the coronary artery only partially blocked
If a person has had a STEMI, the ECG will show:
- an elevated ST segment
- progression to Q wave
- the coronary artery completely blocked
A blockage of blood supply to the heart muscle can result in damage to the heart tissue.
Unstable angina, also known as UA, and NSTEMI are difficult to tell apart initially.
UA is a heart condition where the heart does not get adequate blood or oxygen, which can result in a heart attack. It differs from stable angina, which can occur more frequently and without exertion. UA may also be more severe with more significant damage being done.
Symptoms of unstable angina can feel similar to NSTEMI and may include:
- chest pain that can occur when resting, sleeping, and without exertion
- chest pain that comes unexpectedly
- episodes of pain lasting longer than stable angina and may worsen over time
- chest pain that is not relieved by medication or rest
The likelihood of a person having an NSTEMI or any type of heart attack is substantially increased if:
Heart attacks are often frightening and are considered serious. This applies to an NSTEMI even though it is considered a less severe type of heart attack than a STEMI. Medication and, in some cases, surgery, may be required to treat an NSTEMI.
By paying attention to lifestyle factors, such as diet and exercise, as well as carefully managing any conditions that might increase the risk of an NSTEMI, a person can significantly lower their chances of one occurring.