IM2.{14-16,19-20,23} | ACS Acute Management — Summary & Reflection

KEY TAKEAWAYS

CCU indications: STEMI, high-risk NSTE-ACS (GRACE >140), Killip II–IV, arrhythmia, need for monitoring/reperfusion.

Analgesia: Morphine 2–4 mg IV titrated (+ antiemetic); reduce preload + sympathetic drive. Avoid NSAIDs. Oxygen only if SpO2 <94%.

Nitrate contraindications: SBP <90 mmHg, RV infarction, PDE5 inhibitor within 24 h (sildenafil/vardenafil) or 48 h (tadalafil).

Antiplatelet (DAPT): Aspirin 300 mg loading + ticagrelor 180 mg (preferred in ACS) or clopidogrel 600 mg. DAPT for ≥12 months. GPIIb/IIIa inhibitors as bailout in high-thrombus PCI.

Anticoagulation: UFH IV (PCI), enoxaparin SC (NSTE-ACS), fondaparinux SC (preferred NSTE-ACS per ESC 2023). Supplement with UFH intra-PCI if fondaparinux.

Cardioprotection: Beta-blocker (oral within 24 h if Killip I–II, no contraindication), ACE inhibitor (if LVEF ≤40%, anterior MI, DM, HTN), statin (high-intensity, all ACS), eplerenone (if LVEF ≤40% + HF or DM, within 3–14 days).

Reperfusion — STEMI: Primary PCI preferred if achievable within 120 min of first medical contact (door-to-balloon ≤90 min). Thrombolysis if PCI not available within 120 min, no absolute contraindications; pharmaco-invasive strategy (transfer for angiography 3–24h post-thrombolysis). Absolute thrombolysis contraindications: prior intracranial haemorrhage, ischaemic stroke <3 months, active bleeding, suspected dissection.

ACS complications:
- Arrhythmias: VF → immediate defibrillation; bradycardia/CHB in inferior MI → atropine → temporary pacing; new AF → rate control + anticoagulation (CHA₂DS₂-VASc)
- Mechanical (days 3–5): free wall rupture (tamponade → surgery); VSD (harsh murmur LLSB → surgical/transcatheter closure); papillary muscle rupture (acute MR → surgical repair)
- Pericarditis: aspirin + colchicine
- RV infarction: IV fluids, no nitrates, no diuretics

REFLECT

Return to Suresh — the anterior STEMI patient from the opening hook, now on day 3, with a new harsh pansystolic murmur and SpO2 86%. You have now learned that this presentation is a mechanical VSD from septal rupture. Trace the management decisions you would initiate in the first 30 minutes: call the echo team (confirm VSD, assess LVEF, quantify shunt); obtain urgent cardiothoracic surgery review; initiate vasodilator therapy (IV nitroprusside) if systemic BP tolerates it; prepare for intra-aortic balloon pump support as a bridge. But here is the deeper reflection question: could this complication have been prevented? Suresh arrived 2 hours after symptom onset — well within the reperfusion window. If primary PCI had achieved TIMI 3 flow within 90 minutes of arrival, the anterior wall necrosis would have been substantially smaller, and the risk of septal rupture significantly lower. This is the real-world consequence of the 'time is muscle' principle — not an abstract concept, but a mechanism that translates directly into whether a patient survives day 3 with preserved myocardium or arrives at the operating table with a ruptured septum.