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FORGE CARD #01 — ACS: STEMI & NSTEMI

Aspirin — unless contraindicated

1,544 words ~7 min

FORGE CARD #01 — ACS: STEMI & NSTEMI

Medicine › Cardiology › Acute Coronary Syndromes Yield: ★★★★★ | Frequency: VERY HIGH (Q1+Q3 repeat) | Syllabus: CVS-IHD/ACS

🔑 ONE-LINE ANSWER

ST elevation on ECG in a patient with ischemic chest pain = STEMI = immediate reperfusion (Primary PCI if <90 min, else fibrinolysis if <12h and no contraindications). Do NOT wait for troponin.

🎯 EXAM ATTACK MAP

How the NRE tests this:

  • Pattern 1: Classic chest pain + ST elevation → “Best next step?” → Reperfusion (PCI vs fibrinolysis based on time/distance)
  • Pattern 2: Chest pain + ST depression/T-wave inversion + elevated troponin → NSTEMI → antithrombotics + risk stratification
  • Pattern 3: Post-MI patient with new murmur + shock/pulmonary edema → mechanical complication (discriminate VSD vs acute MR vs free-wall rupture)
  • Pattern 4: Inferior STEMI + hypotension + clear lungs + raised JVP → RV infarct → NO nitrates, give fluids

Favorite disguise: Atypical chest pain in diabetic/elderly woman (silent ischemia) — the “atypical presentation” is actually classic for diabetes. Pain may be dyspnea, fatigue, or epigastric discomfort without chest pain.

Classic distractor: “Wait for troponin before starting treatment” — troponin rises 4-6h after onset. A diagnostic STEMI ECG demands immediate action regardless of troponin.

What discrimination rewards: ECG-first thinking. The ECG is the single most important discriminator. Match management intensity to syndrome severity.

📋 CORE CONCEPT — MUST KNOW

The ACS Spectrum

Feature Stable Angina Unstable Angina NSTEMI STEMI
Trigger Exertion Rest/new/accelerating Rest Rest
ECG ST depression (during pain) ST depression / T inversion ST depression / T inversion / normal Regional ST elevation
Troponin Negative Negative Elevated Elevated (don’t wait)
Priority Outpatient workup Admit + antithrombotics Risk-stratify + early invasive Reperfusion NOW
Reperfusion No No No (usually) YES — immediate

Reperfusion Decision (STEMI)

Factor Primary PCI Fibrinolysis
When preferred Available within 90 min of first medical contact PCI delay >90 min AND symptom onset <12h
Contraindications None absolute Active bleeding, recent stroke, intracranial malignancy, aortic dissection, recent surgery
If fibrinolysed Rescue PCI if reperfusion failure (persistent pain, <50% ST resolution at 60-90 min) —

Immediate ACS Bundle (All ACS Patients)

  1. Aspirin — unless contraindicated
  2. Anticoagulation — per ACS protocol
  3. Nitrates — for pain IF BP allows AND no RV infarct AND no recent PDE-5 inhibitor use
  4. Oxygen — ONLY if hypoxic (SpO2 < 90%) or distressed; NOT routine

Post-MI Mechanical Complications — Discriminator Table

Complication Timing Murmur Hemodynamics Key Clue
Acute MR (papillary muscle rupture) 2-7 days Pansystolic, apex → axilla Pulmonary edema Murmur + pulmonary edema
VSD 3-5 days Harsh pansystolic, left sternal border Shock Harsh murmur + shock
Free-wall rupture 3-5 days None Tamponade, PEA, collapse Sudden collapse

Right Ventricular Infarct

  • Setting: Inferior STEMI (RCA occlusion)
  • Triad: Hypotension + clear lungs + raised JVP
  • Trap: Nitrates → catastrophic preload drop → cardiovascular collapse
  • Management: FLUIDS (preload dependent), NO nitrates

⚠️ TRAP FIELD — ERROR SHIELD

❌ Trap 1: Wait for troponin before acting in STEMI

✅ Reality: A diagnostic STEMI ECG (regional ST elevation with ischemic symptoms) demands immediate reperfusion. Troponin confirms necrosis but rises 4-6h after onset. Delaying reperfusion for enzymes increases myocardial damage. The ECG is the decision-changing clue.

❌ Trap 2: Oxygen for every chest pain patient

✅ Reality: Routine oxygen in normoxic patients (SpO2 > 90%) is NOT indicated and may cause harm (coronary vasoconstriction). Give oxygen ONLY if hypoxic or clinically distressed. Normal saturation = no routine oxygen.

❌ Trap 3: Nitrates in RV infarct

✅ Reality: Inferior STEMI with hypotension, clear lungs, and raised JVP = RV infarction. The RV is preload-dependent. Nitrates drop preload → cardiovascular collapse. Give FLUIDS, not nitrates. This is a classic NRE trap.

❌ Trap 4: All post-MI murmurs are the same

✅ Reality: Discriminate by associated features:

  • Murmur + pulmonary edema → acute MR (papillary muscle rupture)
  • Harsh murmur + shock → VSD
  • Sudden collapse/tamponade → free-wall rupture The associated hemodynamic picture tells you which complication.

❌ Trap 5: Fibrinolysis in NSTEMI

✅ Reality: Fibrinolysis is for STEMI (complete occlusion), NOT NSTEMI. NSTEMI management is antithrombotics + risk stratification. Fibrinolysing NSTEMI increases bleeding benefit without reperfusion benefit. No ST elevation = no fibrinolysis.

🧠 MEMORY ANCHOR

“STEPS” for STEMI Reperfusion Decision:

  • ST elevation confirmed → act NOW
  • Time to PCI < 90 min? → Primary PCI
  • Else if < 12h symptoms → Fibrinolysis (if no contraindications)
  • Post-fibrinolysis: reassess → Rescue PCI if failure
  • Serial ECGs to monitor

“HARSH” for post-MI murmur discrimination:

  • Harsh murmur + shock = VSD
  • Apical murmur + pulmonary edema = acute MR
  • Rupture (free-wall) = sudden collapse/Silent (no murmur)

“NOSE” for RV infarct:

  • Nitrates = NO (contraindicated)
  • Observe JVP (raised)
  • Supine/legs elevated
  • Extend fluids (preload dependent)

🏥 CLINICAL REASONING TRIGGER

“When you see crushing retrosternal chest pain with diaphoresis + regional ST elevation on ECG, immediately activate the STEMI pathway: aspirin, anticoagulation, reperfusion decision. The discriminator is the ECG — ST elevation = complete occlusion = time is myocardium.”

“When you see inferior STEMI + hypotension + clear lungs + raised JVP, think RV infarction. The discriminator is the triad. Give fluids, avoid nitrates.”

“When you see a post-MI patient (day 2-7) with a new murmur, discriminate by the associated picture: pulmonary edema = acute MR, shock = VSD, collapse = free-wall rupture.”

🔗 CROSS-LINKS

→ Heart Failure — Acute MR and papillary muscle rupture cause acute pulmonary edema (cardiogenic shock management overlaps) → ECG Interpretation — ST elevation localization (II, III, aVF = inferior = RCA; V1-V4 = anterior = LAD; I, aVL = lateral = LCx) → Antiplatelet/Anticoagulant Pharmacology — Aspirin, clopidogrel, heparin, GP IIb/IIIa inhibitors in ACS → Pericarditis — Post-MI pericarditis (Dressler syndrome) vs reperfusion pericarditis; diffuse ST elevation vs regional → Aortic Dissection — Must be excluded before fibrinolysis (tearing pain, BP discrepancy, widened mediastinum)

⚡ RAPID FIRE

Q1. A 58-year-old diabetic man presents with crushing retrosternal chest pain for 70 minutes, sweating, nausea. ECG shows ST elevation in II, III, aVF. BP 110/70, SpO2 96%. The nearest PCI-capable center is 3 hours away. What is the best next step?

  • A) Wait for troponin
  • B) IV morphine only
  • C) Fibrinolysis (thrombolysis)
  • D) Transfer for PCI immediately
  • E) Stress testing

→ Answer: C | Why: STEMI with PCI delay >90 min and symptom onset <12h → fibrinolysis is indicated. ST elevation is diagnostic — do not wait for troponin (A). Transfer alone (D) would exceed the time window.

Q2. A 62-year-old man with inferior STEMI develops hypotension (85/50), clear lung fields, and raised JVP. Which is the most appropriate management?

  • A) IV furosemide
  • B) IV nitroglycerin
  • C) IV normal saline bolus
  • D) IV dopamine
  • E) Emergency PCI

→ Answer: C | Why: Triad of inferior STEMI + hypotension + clear lungs + raised JVP = RV infarction. RV is preload-dependent. FLUIDS are first-line. Nitrates (B) and diuretics (A) drop preload → cardiovascular collapse.

Q3. A 55-year-old woman had an anterior STEMI 4 days ago. She now has sudden onset pulmonary edema with a new pansystolic murmur at the apex radiating to the axilla. What is the most likely complication?

  • A) Ventricular septal defect
  • B) Acute mitral regurgitation
  • C) Free-wall rupture
  • D) Ventricular aneurysm
  • E) Aortic regurgitation

→ Answer: B | Why: Post-MI pansystolic murmur at apex + pulmonary edema = acute MR from papillary muscle rupture. VSD (A) would have a harsh left sternal border murmur + shock. Free-wall rupture (C) causes tamponade/collapse, not a murmur.

Q4. A 65-year-old man presents with 2 hours of chest pain. ECG shows ST depression in V4-V6 with T-wave inversion. Troponin is elevated. What is the most appropriate immediate management?

  • A) Fibrinolysis
  • B) Primary PCI
  • C) Aspirin + anticoagulation + risk stratification
  • D) Stress testing
  • E) Discharge with follow-up

→ Answer: C | Why: ST depression + elevated troponin = NSTEMI. Management is antithrombotics + risk stratification (GRACE score) ± early invasive strategy. Fibrinolysis (A) is for STEMI only. Primary PCI (B) is not first-line for stable NSTEMI unless high-risk features.

✓ CONFIDENCE CHECK

“Can I explain the ACS spectrum, the reperfusion decision, and post-MI complications to a peer in 60 seconds?”

Rate: ☆☆☆☆☆

If you hesitated on any zone, revisit that section before moving on.

Source evidence: NRE Dec 2025 recalled paper, NRE May 2026 Intelligence Report (177 MCQs), NRE50 System (Q1+Q3 repeat), MedCORE Day 22, MedCORE Premium CAD_ACS, Hybrid Drill Sheet ACS.