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cardio.stemi.posterior.v1

Isolated posterior wall STEMI (LCx / PDA culprit)

cardiologyacuteadultacuteinpatienttransitionoutpatient
Start encounter →Print handoutPRODUCTION

Phase E variant of cardio.stemi.core.v1 — narrowed to isolated true posterior STEMI (LCx or PDA culprit). Inherits reperfusion + antiplatelet + statin + BB regimen from parent via routing; specializes RECOGNITION pattern (V1-V3 ST↓ + tall R waves V1-V2 mirror image; confirm V7-V9 ST↑) and posteromedial papillary MR vigilance. Manifest pointer reuses cardio.stemi.core.v1 manifest. Design-brief pointer reuses parent (posterior-specific differences documented inline, anchored to Boden 1991 + Khan 2013). Status INTEGRATED until terminology + RxNav-validated drug codes are reconciled. Authored 2026-05-14 by shard-06-cardio-acute as part of Phase E variant batch (inferior/RV/posterior/LMCA).

Entry points (3)

  • imaging
    V1-V3 ST↓ ≥0.5 mm + tall R waves V1-V2 (mirror image of posterior); CONFIRM with V7-V9 ST↑ ≥0.5 mm
    ecg_anterior_st_depression_with_tall_r
  • imaging
    V7-V9 posterior leads ST↑ ≥0.5 mm = isolated true posterior STEMI
    ecg_v7_v9_st_elevation
  • symptom
    Ischemic chest pain + only V1-V3 ST↓ — high suspicion for posterior STEMI; obtain V7-V9 immediately
    ischemic_chest_pain_with_atypical_ecg

Required inputs (8)

  • agerequired
    demographic • used at CONTEXT
    Older patients more likely to present atypically; under-recognition rate higher (Khan PMID 23877546)
  • sbprequired
    vital • used at RED_FLAGS
    Hypotension uncommon in isolated posterior STEMI but indicates large LCx infarct or concurrent inferior involvement
  • ecgrequired
    imaging • used at INITIAL_WORKUP
    Anterior ST↓ V1-V3 ≥0.5 mm + tall R waves V1-V2 with R/S ratio >1 in V2 (mirror image); inferior leads may have subtle changes if RCA-PDA territory
  • ecg_v7_v9required
    imaging • used at INITIAL_WORKUP
    Posterior leads V7-V9 ST↑ ≥0.5 mm CONFIRMS isolated true posterior STEMI; AHA 2025 Class I if any V1-V3 ST↓ raises suspicion
  • troponinrequired
    lab • used at INITIAL_WORKUP
    Confirms infarct; required given ECG-only diagnosis often subtle and easily missed
  • creatininerequired
    lab • used at CONTEXT
    Contrast nephropathy + DOAC dosing if AF post-MI
  • echo_post_pcirequired
    imaging • used at MONITORING
    Posterior wall motion abnormality (often missed on standard parasternal views; need apical 2-chamber + apical long-axis); LV function
  • cor_angiorequired
    imaging • used at TREATMENT
    LCx vs RCA-PDA culprit confirmation; LCx lesions historically under-treated due to ECG silence — vigilant suspicion required

12-phase flow (10)

  1. 1FRAME
    Isolated posterior STEMI = LCx or posterior descending artery culprit; characteristically MISSED because standard 12-lead shows ST↓ rather than ST↑ — historical under-treatment per Khan 2013 PMID 23877546; route to cardio.stemi.core.v1 for the reperfusion arc
    inputs: ecg
    advance: posterior STEMI suspected/confirmed
  2. 2ENTRY
    Cath lab within 90 min once V7-V9 confirms; bedside echo focusing on posterior wall motion (use apical 2-chamber + apical long-axis); IV access
    inputs: age
    advance: cath lab activated
  3. 3CONTEXT
    Allergies, bleed risk, recent surgery, antithrombotic regimen — same as parent
    inputs: sbp, creatinine
    advance: context complete
  4. 4RED_FLAGS
    High miss rate is THE major safety risk — vigilant suspicion + V7-V9 capture (mandatory if V1-V3 ST↓ in ischemic chest pain); mitral regurgitation from posteromedial papillary involvement (LCx territory); concurrent inferior MI extension
    inputs: sbp
    actions: cardiogenic_shock
    advance: V7-V9 obtained + posterior wall echo plan
  5. 5INITIAL_WORKUP
    ECG + V7-V9 + troponin + BMP + CBC + CXR + bedside echo (posterior wall motion via apical views, MR severity, LV function)
    inputs: ecg, ecg_v7_v9, troponin, creatinine, echo_post_pci
    actions: acs_pathway, panel.cardiac, panel.renal
    advance: workup documented
  6. 6BRANCHING_WORKUP
    Primary PCI of LCx or PDA; complete revasc per COMPLETE if multivessel; if hemodynamic instability → CS pathway
    inputs: cor_angio
    advance: reperfusion delivered
  7. 7TREATMENT
    Standard ACS regimen (ASA + ticagrelor + UFH + statin + BB if EF↓) per cardio.stemi.core.v1; same secondary-prevention bundle as parent; vigilance for new MR (posteromedial papillary) on serial echo
    inputs: sbp, creatinine
    actions: protocol.stemi
    advance: reperfusion + secondary-prevention bundle started
  8. 8DISPOSITION
    CICU post-PCI; standard duration similar to inferior MI
    advance: unit assigned
  9. 9MONITORING
    Telemetry; daily exam for new MR murmur; echo at 24-72h for posterior wall motion + MR assessment; standard secondary-prevention timeline
    inputs: echo_post_pci
    actions: panel.cardiac
    advance: wall motion + MR documented
  10. 10FOLLOWUP
    Cardiology follow-up; echo at 40 d for LVEF reassessment + ICD eligibility (lower than anterior); cardiac rehab
    advance: cardiac rehab booked + EF re-assessed