A heart attack (myocardial infarction, or MI) happens when blood flow to part of the heart muscle is blocked. Every minute counts, because heart muscle dies without oxygen.
Signs
- Classic: chest pressure or pain that may spread to the arm, jaw, neck, or back, plus sweating, shortness of breath, and nausea.
- Atypical: women, older adults, and people with diabetes may only have fatigue, indigestion, nausea, or shortness of breath.
First actions
- Call for help and stay with the patient.
- 12-lead ECG within 10 minutes of arrival or of the chest pain starting.
- Oxygen if SpO2 is below 90%.
- Aspirin 162 to 325 mg, chewed, unless the patient is allergic or the provider says no.
- Nitroglycerin 0.4 mg under the tongue every 5 minutes, up to 3 doses, if ordered and BP allows.
- IV access and labs, including troponin.
When to hold nitroglycerin
- Systolic BP below 90 mm Hg
- Use of sildenafil, tadalafil, or similar drugs in the last 24 to 48 hours
- Suspected right ventricular MI, as directed by the provider
STEMI vs. NSTEMI
| STEMI | NSTEMI | |
|---|---|---|
| ECG | ST elevation | No ST elevation (may have ST depression or T wave changes) |
| Troponin | Elevated | Elevated |
| Treatment | Emergency cath lab to open the artery, ideally within 90 minutes of arrival | Medications, then cath based on risk |
Troponin
Troponin is the main lab for heart muscle damage. It rises within hours and stays up for days, so it is usually checked more than once.
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Quick answers
What is the first thing to do for a patient with chest pain?
Stay with the patient, call for help, and get a 12-lead ECG within 10 minutes, then give oxygen if SpO2 is under 90%, aspirin, and nitroglycerin as ordered.
When should nitroglycerin be held?
Hold it if systolic BP is below 90 mm Hg, if the patient took sildenafil or a similar drug recently, or if the provider suspects a right ventricular MI.
Evidence & Clinical Sources
- ACC/AHA clinical guidelines
- American Heart Association CPR and ECC Guidelines
- Hinkle & Cheever, Brunner & Suddarth's Textbook of Medical-Surgical Nursing, Wolters Kluwer
Reviewed against current guidelines and drug labels. Always follow your program, a current drug reference, and facility policy. Our sources policy
For learning only. Lab ranges and policies vary. Always follow your nursing program, a current drug reference, and your facility's policies.