The NSTEMI medical abbreviation stands for non ST elevation myocardial infarction, a heart attack in which blood tests show heart muscle damage but the electrocardiogram does not show the ST segment rising that marks the other main type. It is usually caused by a narrowed coronary artery that is partly blocked.
NSTEMI belongs to the group called acute coronary syndrome, written ACS. You will see it in emergency notes, cardiology consults and discharge summaries. This page explains each piece of the name, compares it with STEMI and unstable angina, and decodes the shorthand that tends to follow it, from troponin to cath lab.
At a glance
Stands for
Non ST elevation myocardial infarctionWritten as
NSTEMI, non STEMI, NSTE MIBelongs to
Acute coronary syndrome (ACS), the NSTE ACS groupKey tests
Troponin blood test and EKGDo not confuse with
STEMI (ST elevation MI) and unstable anginaSpecialty
Cardiology, emergency medicine
Taking the name apart
Each part of the abbreviation has a job. Myocardial means heart muscle, from myo for muscle and cardi for heart. Infarction means tissue death from a lack of blood flow. ST elevation refers to a part of the EKG tracing, the ST segment, rising above its baseline. Non says that rise is absent.
So NSTEMI is a heart attack confirmed by blood tests, without ST elevation on the tracing. The EKG may still show other changes, such as ST depression or flipped T waves, or it may look close to normal.
NSTEMI medical abbreviation versus STEMI and unstable angina
These three sit side by side in emergency care, and the difference comes down to the EKG and the troponin result.
| Condition | ST elevation on EKG | Troponin raised |
|---|---|---|
| STEMI | Yes | Yes |
| NSTEMI | No | Yes |
| Unstable angina | No | No |
STEMI usually means an artery is fully blocked and needs to be opened as fast as possible. NSTEMI usually reflects a partial blockage. That does not make it minor; it is still a heart attack and needs prompt hospital care. Both fall under the wider heading MI.
Reading an NSTEMI admission note
Emergency department note: "64 yo F, CP x 3 hr, EKG with ST depression V4 to V6, hs trop 85 then 240, NSTEMI, start ASA, heparin, cards consult." This says a 64 year old woman had chest pain for three hours, the EKG showed ST depression in certain leads, a high sensitivity troponin rose between two draws, and the team diagnosed NSTEMI, started aspirin and heparin, and called cardiology.
CP here means chest pain, though it has other meanings on its own CP page. Troponin cutoffs depend on the lab and the test used, so each report lists its own reference range. Lines like this show the style of a note, not a treatment plan.
Treatment shorthand after an NSTEMI
Hospital teams commonly start medicines to stop the clot from growing, such as aspirin plus a second antiplatelet medicine, together called DAPT, and a blood thinner such as heparin. Many patients then have a coronary angiogram, often timed within a day or so depending on risk, to look at the arteries.
- Cath or LHC: a left heart catheterization to image the arteries
- PCI: a catheter procedure that props a narrowed artery open with a stent
- CABG: bypass surgery if several arteries are involved
The order and timing are decided by the cardiology team.
Where NSTEMI fits in a long term history
After discharge, NSTEMI stays in the history as an earlier event, often written h/o NSTEMI or s/p NSTEMI. It usually sits beside CAD or ischemic heart disease and risk factors such as high blood pressure and diabetes. Cardiac rehabilitation is often recommended after a heart attack.
Other heart condition shorthand, including AMI and ACS, is grouped in the diagnosis abbreviations section.
Questions for the cardiology team
- Which artery was involved, and was a stent placed?
- How much did the heart muscle pumping change?
- How long should the antiplatelet medicines continue?
- Is cardiac rehabilitation recommended, and when does it start?
- What symptoms mean I should call emergency services?
What you read here describes the term in general. Decisions about tests, medicines and recovery after an NSTEMI belong to your cardiologist and care team, so bring your questions to them.
Frequently asked questions
Is an NSTEMI a real heart attack?
Yes. An NSTEMI is a heart attack, confirmed by a rise in troponin showing heart muscle damage. It differs from a STEMI in the EKG pattern, not in whether damage occurred.
What is the difference between NSTEMI and STEMI?
A STEMI shows ST segment elevation on the EKG and usually means a fully blocked artery. An NSTEMI does not show ST elevation and often reflects a partially blocked artery. Both raise troponin.
How do you pronounce NSTEMI?
Most clinicians say it as a word, EN stem ee. Some spell out non STEMI instead.
What does type 2 NSTEMI mean?
Some notes describe a type 2 MI, where the heart muscle is damaged because oxygen demand outstrips supply, for example during severe anemia or a very fast heart rate, rather than from a ruptured plaque. Your care team can explain which type applies.