STEMI

Exam Cram

• STEMI: ST Elevation Myocardial Infarction

• Aetiology: coronary artery clot causing transmural infarction

• Diagnosis: ECG- ST elevation

• Management: primary percutanous coronary intervention within 2 hours

Outline

Assessment

History: 

• Severe central chest pain at rest, radiating to left/ right chest or carotids

• Vasculopath background

Examination

• Tachy or bradycardic

• Hypotensive

Investigations

• ECG: ST elevation or equivalent

• Troponin immediately & repeat in 3hrs- can be very high

• Chest XR

• Baseline bloods: FBC, EUC, LFT +- CRP

• Consider d-dimer/ CTPA or CT-Angio

Diagnosis & Classification

Diagnostic Criteria: ECG

Differential Diagnoses: NSTEMI , Aortic Dissection , Pulmonary Embolus 

Management

Acute:

• Call Cardiology Consultant / Registrar to arrange

  1. Primary PCI < 2hrs

  2. Antiplatelets as per trust policy

Long Term: secondary prevention

• Atorvastatin 80mg nocte

• ACE inhibitor 

• Beta blocker

• Aspirin 100mg OD

• SGLT-2 inhibitor if signs of CHF or hyperglcaemia

Med Reg Notes

Localise the Lesion

LBBB- LAD

No GTN in Right Coronary Artery Occulsion

GTN can drop the preload

Myocardial Complications

Bradycardias

• 48hrs tolerate, if persist insert pacing wire

• Insert trans-cutaneous pacing if within 48hrs, RCA infarction causing unstable features (heart failure, infarction, syncope, hypotension) prior to PCI

Papillary Muscle Rupture

• Usually two days post MI

• Acute Mitral Regurgitation & LV failure

• Management

  • Reduce afterload with Sodium Nitropruside & duiretics (limited by hypotension)

  • Intra-aortic balloon pumps commonly required

  • Surgical valve repair

Dressler's Syndrome

Death

Differentials

Aortic Dissection can dissect down to the coronary arteries and is rarely detected during PCI. A type A aortic dissection can present with ST elevation in the inferior leads

Posterior STEMI

Can present with ST depression in anterior leads, requires posterior leads V7-9. 

STEMI Equivalents

• new LBBB

Fibrinolytic therapy

Option for those unable to access PCI, most commonly due to geography. 

References & Resources

1. Alsaad AA, Odunukan OW, Patton JN. Ascending aortic dissection presented as inferior myocardial infarction: a clinical and diagnostic mimicry. BMJ Case Rep. 2016 Dec 20;2016:bcr2016217543. doi: 10.1136/bcr-2016-217543. PMID: 27999129; PMCID: PMC5174843.

Written in 2025