Immediate priorities

1. Stabilize and monitor
   • ABCs, continuous cardiac monitoring, defibrillator pads, 2 IV lines.
   • Check SpO₂, ABG/VBG with lactate, capillary glucose, temperature, urine output with catheter.
   • Repeat 12-lead ECG and serial high-sensitivity troponin.
   • CBC, electrolytes including K/Mg, urea/creatinine/eGFR, LFT, coagulation profile, BNP if helpful, blood group/cross-match.
   • Portable chest X-ray and focused echo: regional wall-motion abnormality, RV infarct, mechanical MI complication, significant valvular lesion, pericardial effusion.
   • Urgent noncontrast CT brain is reasonable before thrombolysis or full anticoagulation if altered sensorium is unexplained, focal deficit is present, or intracranial bleeding/stroke is possible.
2. Determine whether she is in cardiogenic shock
   • BP 100/70 alone does not prove shock, but altered sensorium, oliguria, cool extremities, rising lactate, narrow pulse pressure, or worsening creatinine would be concerning.
   • Avoid routine IV fluid boluses because she appears congested. Give only a cautious small fluid challenge if there is convincing hypovolemia or RV infarction and no pulmonary congestion.
   • Give oxygen only if hypoxemic, generally SpO₂ <90%, and use NIV/intubation if pulmonary edema or respiratory failure develops. The emergency text recommends treating hypotension, pulmonary edema, and arrhythmias while initiating STEMI reperfusion without delay (The Washington Manual of Medical Therapeutics, p. 150).

Reperfusion: this is the main decision

• If repeat ECG confirms ongoing STEMI or there is ongoing ischemia, shock, malignant arrhythmia, or acute HF due to MI, activate the cath lab for urgent coronary angiography and primary PCI.
• Creatinine 2.5 mg/dL is not by itself a reason to withhold life-saving angiography/PCI. Use radial access if feasible, minimize contrast volume, avoid nephrotoxins, document eGFR, and closely follow renal function. In a congested low-EF patient, do not give indiscriminate prophylactic hydration.
• The reported "four days" of edema/facial puffiness is not necessarily the onset of MI. Clarify the onset of ischemic symptoms and ECG evolution. Late-presenting STEMI with ongoing ischemia, shock, or HF still merits urgent invasive assessment.
• Fibrinolysis should not be reflexively given in this patient. At 4 days, with altered sensorium and uncertain diagnosis/timing, first exclude contraindications such as intracranial hemorrhage or acute ischemic stroke. If PCI is unavailable and she has a clearly acute STEMI within the appropriate time window, this must be a cardiology-led decision.

Antithrombotic and ACS treatment

• Give chewed aspirin promptly, unless true allergy or active major bleeding.
• Give a P2Y12 inhibitor per the anticipated PCI strategy and bleeding risk. Because AF may require oral anticoagulation afterward, cardiology often favors a regimen that minimizes prolonged triple therapy, frequently using clopidogrel as the P2Y12 agent.
• For procedural/acute anticoagulation in significant renal impairment or fluctuating renal function, unfractionated heparin is often preferred because it can be titrated and reversed. Do not use fixed dosing without weight, eGFR, bleeding assessment, and local ACS protocol.
• Start a high-intensity statin unless contraindicated. Current ACS guidance recommends high-intensity statin therapy for ACS and DAPT as the default when bleeding risk permits (ACC summary).
• Avoid NSAIDs.
• Avoid routine nitrates at present because SBP is only 100 mmHg and she may have low output. Do not give nitrates if RV infarct, hypotension, or phosphodiesterase-5 inhibitor use is possible.

Pulmonary/systemic congestion with EF 30%

• If pulmonary/systemic congestion is confirmed, use carefully titrated IV loop diuretic, with hourly urine output, daily weight, electrolyte checks, and repeated assessment of BP/perfusion.
• A small creatinine rise during successful decongestion can occur, but progressive oliguria, worsening hypotension, rising lactate, or cold extremities indicates poor perfusion and demands escalation, not simply more diuretic.
• Do not start or up-titrate ACE inhibitor/ARB/ARNI, mineralocorticoid antagonist, or SGLT2 inhibitor during an unstable hypotensive acute phase with AKI. Reassess guideline-directed HFrEF therapy after stabilization.
• Hold or avoid starting beta-blocker during active pulmonary edema, shock, or hypoperfusion. Do not abruptly stop a chronic beta-blocker without a compelling shock-related reason.

Atrial fibrillation

• If AF with rapid ventricular response is causing hypotension, ongoing ischemia, pulmonary edema, or altered mentation: immediate synchronized electrical cardioversion is indicated. Emergency guidance specifically recommends urgent cardioversion for recent-onset AF with RVR causing hypotension, ischemia, or pulmonary edema.
• If she is not immediately unstable from AF but needs rate control:
  • Avoid diltiazem and verapamil because of EF 30% and decompensated HF.
  • Avoid aggressive beta-blockade initially if congested, hypotensive, or in low-output failure.
  • IV amiodarone can be considered in the monitored ICU setting, especially if rate/rhythm control is needed with severe LV dysfunction, while watching for hypotension and QT effects.
  • Digoxin may be considered for rate control in HFrEF but requires reduced dosing and level monitoring in renal dysfunction. It is not a rapid solution in a critically ill high-catecholamine state.
• Long-term AF anticoagulation is likely indicated due to age, sex, HF, and vascular disease, but final timing and drug selection depend on CT brain, bleeding risk, PCI/stent plan, eGFR, and whether this is truly acute MI. Do not automatically use prolonged triple therapy.

If shock/hypoperfusion is present

• Transfer or manage in a center with cath lab and mechanical circulatory-support capability.
• Use norepinephrine if vasopressor support is needed to maintain perfusion. If low cardiac output persists after BP support, an inotrope such as dobutamine may be considered by the critical-care/cardiology team.
• Prompt revascularization is the priority; selected MI-related cardiogenic-shock patients may require temporary mechanical circulatory support.

Important diagnostic cautions