Inferior wall STEMI (RCA / LCx culprit)
Encounter flow
10/12 authoredCanonical 12-phase frame with authored status for this dossier.
Frame
Inferior STEMI = RCA (most common, ≈80%) or LCx culprit; smaller territory than anterior typically; characteristic bradyarrhythmia + AV-block + RV-extension complication profile; route to cardio.stemi.core.v1 for the reperfusion arc
inferior STEMI confirmed on ECG
Patient inputs (9)
Older patients have higher AV-block risk after inferior MI
Contrast nephropathy + DOAC dosing if AF post-MI
II/III/aVF ST↑ defines inferior; ST↑ III > II suggests RCA, ST↑ II > III + I/aVL ST↑ suggests LCx; ALWAYS obtain V4R for RV-extension screening
V4R ST↑ ≥1 mm = RV extension → route to cardio.stemi.right-ventricular.v1; Class I obligatory in inferior STEMI per AHA 2025
Confirms infarct; smaller absolute peak vs anterior MI (smaller territory typically)
LV + RV function, inferior wall motion, mitral apparatus (papillary rupture more often posteromedial in inferior MI)
Hypotension in inferior MI — distinguish vagal (responds to atropine + fluids) from RV extension (preload-dependent)
Bradyarrhythmia common in inferior MI (Berger PMID 1735156); transient AV block in 12-20%
RCA vs LCx culprit confirmation; complete revasc decision per COMPLETE PMID 31475795
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Severity triggers (5)
- informationallife_threateningposteromedial_papillary_muscle_ruptureNew harsh apical/axillary holosystolic murmur post-inferior-MI + acute pulmonary edema → posteromedial papillary rupture (single-vessel blood supply from PDA, more vulnerable than anterolateral)Trigger could not be auto-evaluated — needs clinician judgement.
- informationalsevereinferior_stemi_with_high_grade_av_block2°-3° AV block in inferior MI; usually transient (resolves <48h with reperfusion) but can be symptomatic — Mobitz I with hypotension or complete heart blockTrigger could not be auto-evaluated — needs clinician judgement.
- informationalsevereinferior_stemi_with_v4r_st_elevationV4R ST↑ ≥1 mm in inferior STEMI = RV extension (proximal RCA) — preload-dependentTrigger could not be auto-evaluated — needs clinician judgement.
- informationalsevereinferior_stemi_with_persistent_hypotension_post_atropineInferior STEMI + SBP <90 not responsive to atropine + fluids — assess for RV extension, mechanical complication, or evolving cardiogenic shockTrigger could not be auto-evaluated — needs clinician judgement.
- informationalseverepersistent_high_grade_av_block_beyond_5_daysMobitz II or 3° AV block persisting >5d post-inferior-MI despite reperfusionTrigger could not be auto-evaluated — needs clinician judgement.
Workflow calculators
Run this disease's risk and dosing calculators inline.
Recommended regimen
Inferior STEMI complication phenotype — adds to parent cardio.stemi.core.v1 reperfusion regimen- aspirinfirst lineantiplatelet_cox1162-325 mg chewed • PO • load + 81 mg dailytriggers: stemi_post_roscACC/AHA 2025 ACS Class I; same as parentrxcui 243670
- ticagrelorfirst linep2y12_inhibitor180 mg load → 90 mg BID • PO • BID × 12 mo default DAPTtriggers: stemi_pci_plannedPLATO PMID 19717846; same as parentrxcui 1116632
- atropinerescueantimuscarinic0.5 mg IV q3-5 min, max 3 mg • IV • PRNtriggers: symptomatic_bradycardia, av_block_with_hypotensionVagal-mediated bradycardia (Bezold-Jarisch reflex) common in inferior MI; first-line per Kusumoto 2018 PMID 30412709rxcui 1223
- metoprololcontraindication substitutebeta_blocker12.5-25 mg PO BID — DEFER until rhythm stable • PO • deferredtriggers: post_inferior_mi_no_av_block_no_bradyBB normally Class I post-MI, but AVOID/defer in acute inferior MI if HR <60, 2°-3° AV block, or hypotension; reintroduce after 48h once rhythm stable — encoded as contraindication_substitute (avoid in this phenotype, restart in chronic management arm)rxcui 6918
outpatient playbook — drug actions (1)
- 1. continue secondary-prevention bundlerxcui 243670ASA 81 + ticagrelor 90 BID × 12 mo + atorvastatin 80 + BB • PO • as scheduledtrigger: post-inferior-MIAHA 2025
Auto-drafted A&P note
outpatientSubjective
- Possible entry pathways: ST elevation II/III/aVF + reciprocal ST↓ I/aVL (inferior STEMI); Ischemic chest pain + inferior STEMI ECG → emergent cath within 90 min; Inferior STEMI on standard ECG → mandatory V4R lead to screen for RV extension.
Objective
- No vitals, labs, or imaging entered for this encounter.
Assessment
**Inferior wall STEMI (RCA / LCx culprit)** (cardio.stemi.inferior.v1). Scope: Inferior STEMI = RCA (most common, ≈80%) or LCx culprit; smaller territory than anterior typically; characteristic bradyarrhythmia + AV-block + RV-extension complication profile; route to cardio.stemi.core.v1 for the reperfusion arc No severity triggers fired against current inputs.
Plan
Regimen axis: **Inferior STEMI complication phenotype — adds to parent cardio.stemi.core.v1 reperfusion regimen**. 1. aspirin 162-325 mg chewed PO load + 81 mg daily (antiplatelet_cox1, first line) — ACC/AHA 2025 ACS Class I; same as parent 2. ticagrelor 180 mg load → 90 mg BID PO BID × 12 mo default DAPT (p2y12_inhibitor, first line) — PLATO PMID 19717846; same as parent 3. atropine 0.5 mg IV q3-5 min, max 3 mg IV PRN (antimuscarinic, rescue) — Vagal-mediated bradycardia (Bezold-Jarisch reflex) common in inferior MI; first-line per Kusumoto 2018 PMID 30412709 4. metoprolol 12.5-25 mg PO BID — DEFER until rhythm stable PO deferred (beta_blocker, contraindication substitute) — BB normally Class I post-MI, but AVOID/defer in acute inferior MI if HR <60, 2°-3° AV block, or hypotension; reintroduce after 48h once rhythm stable — encoded as contraindication_substitute (avoid in this phenotype, restart in chronic management arm) Setting playbook (outpatient) — Long-term cardiology surveillance: secondary prevention bundle maintenance; lower ICD-eligibility rate (smaller infarct typical); cardiac rehab completion 5. continue secondary-prevention bundle ASA 81 + ticagrelor 90 BID × 12 mo + atorvastatin 80 + BB PO as scheduled — post-inferior-MI (AHA 2025) Non-pharmacologic actions: - Cardiac rehab maintenance phase - Driving restriction per state law if pacing or VF AVOID / contraindication checks: - Beta_blocker_avoid_in_acute_inferior_mi_if_av_block_or_brady (AHA 2025 / Kusumoto 2018) - Atropine_caution_in_glaucoma_and_obstructive_uropathy (label) - Transcutaneous_pacing_for_symptomatic_high_grade_av_block (Kusumoto 2018 Class I)
Monitoring
Regimen monitoring: - continuous telemetry x 72h for av block recurrence - V4R lead within 10 min of inferior stemi recognition - serial HR and BP q15min first 2h Setting (outpatient) monitoring: - Quarterly + annual EF + lipid Follow-up plan: Cardiology follow-up; echo at 40 d for LVEF reassessment; cardiac rehab; lower ICD-eligibility rate than anterior (smaller infarct typically) - Close-out criterion: cardiac rehab booked + EF re-assessed Monitoring phase: Telemetry continuous; daily exam for new murmur (papillary); rhythm follow-up — most AV block resolves <48h with reperfusion; if persistent >5d consider permanent pacing per Kusumoto 2018
Disposition
Current setting: outpatient — Long-term cardiology surveillance: secondary prevention bundle maintenance; lower ICD-eligibility rate (smaller infarct typical); cardiac rehab completion Disposition criteria: - Long-term continuation; cross-link to cardio.hf.core.v1 if HFrEF persists Escalation triggers (move to higher acuity): - EF declining despite GDMT → advanced HF eval - Recurrent angina → cath re-eval
Earlier-Return Triggers
Return-precaution thresholds (watch for): - [LIFE_THREATENING] New harsh apical/axillary holosystolic murmur post-inferior-MI + acute pulmonary edema → posteromedial papillary rupture (single-vessel blood supply from PDA, more vulnerable than anterolateral) - [SEVERE] 2°-3° AV block in inferior MI; usually transient (resolves <48h with reperfusion) but can be symptomatic — Mobitz I with hypotension or complete heart block - [SEVERE] V4R ST↑ ≥1 mm in inferior STEMI = RV extension (proximal RCA) — preload-dependent
Citations
- 2025 ACC/AHA ACS Guideline + ESC 2023 ACS + 2018 ACC/AHA/HRS Bradycardia Guideline [PMID:37622670](https://pubmed.ncbi.nlm.nih.gov/37622670/) - Cited evidence (PMID 35718438) [PMID:35718438](https://pubmed.ncbi.nlm.nih.gov/35718438/) - Cited evidence (PMID 38587234) [PMID:38587234](https://pubmed.ncbi.nlm.nih.gov/38587234/) - Cited evidence (PMID 31475795) [PMID:31475795](https://pubmed.ncbi.nlm.nih.gov/31475795/) - Cited evidence (PMID 1735156) [PMID:1735156](https://pubmed.ncbi.nlm.nih.gov/1735156/) Last reconciled with current guidelines: 2026-05-14.
- 2025 ACC/AHA ACS Guideline + ESC 2023 ACS + 2018 ACC/AHA/HRS Bradycardia Guideline — PMID:37622670
- Cited evidence (PMID 35718438) — PMID:35718438
- Cited evidence (PMID 38587234) — PMID:38587234
- Cited evidence (PMID 31475795) — PMID:31475795
- Cited evidence (PMID 1735156) — PMID:1735156