I am a cardiac PCU nurse and I see STEMI’s and NSTEMI’s all the time.

An NSTEMI is NSTEMI (Non-ST-Elevation Myocardial Infarction) is a type of heart attack where a coronary artery is partially blocked, reducing blood flow and damaging heart muscle, but without the significant ST-segment elevation seen in a STEMI on an EKG. Diagnosed by elevated cardiac enzymes (like troponin) in blood tests despite normal or subtle EKG changes (like ST depression/T-wave inversion), NSTEMI still requires urgent treatment with medications and possibly procedures to restore blood flow, as it carries serious risks, including future heart attacks.  

Key Characteristics

• Partial Blockage: A blood clot partially blocks a heart artery, not completely. 
• ECG Findings: Doesn’t show ST elevation but might show ST depression or T-wave inversion. 
• Biomarkers: Blood tests reveal elevated cardiac troponin, indicating heart muscle damage. 
• Symptoms: Similar to other heart attacks: chest pain, shortness of breath, nausea, lightheadedness, pain radiating to jaw/back. 

How it Differs from STEMI

• STEMI (ST-Elevation MI): Complete blockage, significant ST elevation on EKG, more severe immediate emergency. 
• NSTEMI: Partial blockage, no ST elevation, diagnosed with blood tests, less immediately dramatic but still very serious. 

Treatment & Management

Immediate: Aspirin, heparin (blood thinners), beta-blockers, nitrates (nitroglycerine) to stabilize the patient.

Aspirin acts as a antiplatelet medication. It is one of the medications that stops plateletes from sticking together to form dangerous blood clots. That is why they have you chew aspirin during chest pain.

Heparin is a fast-acting anticoagulant (blood thinner) medication used to prevent and treat blood clots in veins, arteries, and lungs. It is administered via injection (intravenous or subcutaneous) and does not break down existing clots, but prevents them from growing and new ones from forming. 

Function: Heparin works by binding to a naturally occurring protein in the blood called antithrombin III, which enhances antithrombin’s ability to inactivate key blood clotting factors, such as thrombin and factor.

Beta-blockers are prescription drugs that slow your heart rate and lower blood pressure by blocking adrenaline (epinephrine), reducing the heart’s workload, and are used for heart conditions like angina and heart failure, high blood pressure, and migraines, as well as anxiety symptoms, working by blocking beta-adrenergic receptors in the body. Common examples include metoprolol, atenolol, and propranolol, but they can cause fatigue, dizziness, and cold hands, and should be taken exactly as prescribed.  

How they work

• Block Adrenaline: They stop adrenaline or epinephrine from binding to beta receptors, reducing the heart’s speed and force. 
• Lower Blood Pressure: By slowing the heart and relaxing blood vessels, they decrease blood pressure and the heart’s demand for oxygen. 
• Kidney Hormone: Some also block a hormone that narrows blood vessels, further helping blood pressure. 

NORMAL EKG tracing

ST Elevation

ST DEPRESSION

Further Steps: 
Cardiac catheterization (angiogram) to find blockages, potentially stenting (PCI) or bypass surgery (CABG or Cornonary Artery Bipass Graft) .