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cardio.cardiogenic-shock.bacterial-myocarditis.v1

Cardiogenic shock — bacterial myocarditis (Staph, Strep, diphtheria, TB, meningococcal)

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Phase E variant of cardio.cardiogenic-shock.core.v1 — narrowed to bacterial myocarditis with cardiogenic shock. Etiologies: Staphylococcus (most common), Streptococcus (post-infectious / direct), diphtheria toxin (rare with vaccination but devastating), tuberculous, meningococcal sepsis, Lyme overlap, atypicals (Mycoplasma, Chlamydia, Coxiella, Brucella, Leptospira, Rickettsia). Workup: blood cultures × 3 BEFORE antibiotics; cardiac MRI Lake Louise; EMB if etiology uncertain or refractory; PCR for atypicals; HIV testing; PPD/IGRA + sputum AFB if TB risk; TEE if endocarditis suspicion; throat swab if diphtheria. Treatment ACUTE: targeted antibiotics — empiric vancomycin 25-30 mg/kg + ceftriaxone 2 g IV q24h covers MSSA/MRSA/Strep/Listeria/meningococcal; tailor within 48-72 h. Standard CS support — NE first-line; cautious dobutamine (arrhythmogenic). AVOID immunosuppression (worsens infection — distinct from autoimmune myocarditis). Etiology-specific: Diphtheria — equine antitoxin from CDC stockpile + erythromycin/penicillin; vaccinate contacts. TB — RIPE × 2 mo intensive then RI × 4 mo continuation + steroids if pericardial component. Meningococcal — ceftriaxone + dexamethasone (if meningitis component) + supportive + droplet isolation + close-contact chemoprophylaxis (rifampin or ciprofloxacin per CDC 2024). Long-term: GDMT 4-pillar if persistent EF<40; recovery often if etiology controlled; cardiac MRI follow-up at 3-6 mo for fibrosis; vaccination updates (diphtheria booster q10y, pneumococcal, meningococcal if at-risk, COVID-19, influenza); contact tracing per pathogen. Inherits parent CS framework; specialises for bacterial myocarditis — targeted antibiotic stewardship, AVOIDANCE of immunosuppression confusion with autoimmune myocarditis, contact tracing + vaccination prevention, MDR-organism stewardship. Status INTEGRATED until terminology + RxNav-validated drug codes are reconciled. Authored 2026-05-15 by shard-06-cardio-acute as Phase E wave 22 infectious cardiac variant.

Entry points (6)

  • symptom
    Cardiogenic shock + fever + signs of bacteremia → bacterial myocarditis suspicion (Staph, Strep, meningococcal)
    cs_with_fever_and_bacteremia_signs
  • history
    Recent severe pharyngitis (gray membrane) in unvaccinated patient + new carditis → diphtheria toxin myocarditis (medical emergency, antitoxin from CDC)
    recent_pharyngitis_with_carditis_in_unvaccinated
  • symptom
    Subacute carditis + constitutional symptoms + pericardial effusion in HIV-positive / immunocompromised → TB myocarditis evaluation
    tuberculous_myocarditis_with_pericardial_effusion_in_immunocompromised
  • symptom
    Meningococcemia (purpura fulminans, sepsis) with carditis features → meningococcal myocarditis
    meningococcemia_with_carditis
  • lab_abnormality
    Positive blood cultures (Staph, Strep, atypicals) + new LV dysfunction or AV block → bacterial myocarditis with bacteremic seeding
    positive_blood_cultures_with_new_carditis
  • history
    Animal / tick / vector exposure + new carditis → atypicals (Coxiella Q-fever, Brucella, Leptospira, Rickettsia)
    tick_or_animal_exposure_with_carditis

Required inputs (22)

  • agerequired
    demographic • used at CONTEXT
    Bacterial myocarditis can affect any age; diphtheria classic in <5 y or unvaccinated adults; TB more common in older / immunocompromised
  • sbprequired
    vital • used at RED_FLAGS
    SCAI 2022 staging baseline; bacterial myocarditis CS often combined with septic shock — distributive + cardiogenic mixed picture
  • hrrequired
    vital • used at RED_FLAGS
    Tachycardia from sepsis + LV dysfunction; AV block in diphtheria / Lyme / TB myocarditis with conduction system involvement
  • temprequired
    vital • used at RED_FLAGS
    Fever almost always present in active bacterial myocarditis; temp >38.5 = SIRS criterion + sepsis bundle activation
  • spo2required
    vital • used at INITIAL_WORKUP
    Pulm congestion from LV dysfunction + ARDS from sepsis; intubation often needed
  • lactaterequired
    lab • used at RED_FLAGS
    SCAI staging anchor + sepsis bundle marker; ≥2 = SCAI C+; ≥4 = severe shock
  • troponinrequired
    lab • used at INITIAL_WORKUP
    Elevated in active myocarditis; trend during recovery; pseudo-MI pattern possible
  • bnp_ntprobnprequired
    lab • used at INITIAL_WORKUP
    Elevated proportional to LV dysfunction; trends recovery on antibiotics
  • blood_culturesrequired
    lab • used at INITIAL_WORKUP
    MANDATORY × 3 BEFORE antibiotics — identifies organism + drives targeted therapy; modified Duke criteria for endocarditis exclusion
  • cbcrequired
    lab • used at INITIAL_WORKUP
    Leukocytosis + left shift in bacterial; thrombocytopenia in TB / meningococcal / sepsis-DIC
  • creatininerequired
    lab • used at CONTEXT
    Baseline for vancomycin trough monitoring + nephrotoxic agent dosing; AKI common in mixed shock
  • lftrequired
    lab • used at CONTEXT
    TB drug hepatotoxicity baseline; sepsis-related transaminitis; congestive hepatopathy from RV dysfunction
  • hiv_test
    lab • used at BRANCHING_WORKUP
    TB risk + immunocompromised classification; TB myocarditis more common in HIV+; affects treatment intensity
  • ppd_or_igra
    lab • used at BRANCHING_WORKUP
    TB myocarditis screen if subacute presentation + endemic exposure / immunocompromised
  • ecgrequired
    imaging • used at INITIAL_WORKUP
    Pseudo-MI ST changes, AV block (diphtheria / TB / Lyme overlap), arrhythmia; serial monitoring
  • echorequired
    imaging • used at INITIAL_WORKUP
    LV function, RV strain, pericardial effusion (TB, meningococcal), valvular function (rule out IE), wall motion
  • cardiac_mri
    imaging • used at BRANCHING_WORKUP
    Lake Louise criteria (T2/T1 mapping + LGE) for myocarditis confirmation + prognostication
  • cxrrequired
    imaging • used at INITIAL_WORKUP
    Pulm congestion + cavitary lesions if TB + cardiomegaly + pericardial effusion silhouette
  • vaccination_historyrequired
    history • used at CONTEXT
    Diphtheria + meningococcal + pneumococcal + COVID-19 status drives risk; gaps suggest preventable etiology
  • tb_exposure_history
    history • used at CONTEXT
    Endemic region, household contact, prior treatment, BCG history; HIV co-infection risk
  • animal_or_vector_exposure
    history • used at CONTEXT
    Atypicals — Coxiella (livestock), Brucella (unpasteurized dairy), Leptospira (water/rodents), Rickettsia (ticks/fleas)
  • penicillin_allergyrequired
    history • used at CONTEXT
    Drives antibiotic selection — vancomycin alone if anaphylactic to beta-lactams; daptomycin alternative

12-phase flow (12)

  1. 1FRAME
    Bacterial myocarditis with cardiogenic shock — distinct from viral / autoimmune / Lyme by bacterial pathogen + targeted antibiotic therapy + AVOIDANCE of immunosuppression; identify etiology subgroup (Staph/Strep/diphtheria/TB/meningococcal/atypical) for tailored regimen
    inputs: age, temp, sbp
    advance: Bacterial myocarditis confirmed as working diagnosis with etiologic subgroup identified or empiric coverage started
  2. 2ENTRY
    Mobilize cards + ID + ICU teams immediately; activate sepsis bundle alongside CS workup; cardiac MRI / EMB pathway initiation; serial cultures + organism-targeted PCR
    inputs: sbp, hr, temp
    advance: Multi-disciplinary team activated + sepsis bundle started in parallel with CS workup
  3. 3CONTEXT
    Vaccination history (diphtheria, meningococcal, pneumococcal), TB exposure, animal/vector exposure, penicillin allergy, immunocompromise, prior cardiac history, comorbidities
    inputs: vaccination_history, tb_exposure_history, animal_or_vector_exposure, penicillin_allergy, creatinine, lft
    advance: Context complete and antibiotic plan drafted (empiric → targeted within 48-72 h)
  4. 4RED_FLAGS
    SBP <90 + lactate ≥2 → SCAI C+; sepsis bundle activation if temp >38.5 or hypothermia + suspected source; high-grade AV block (diphtheria, TB) → temporary pacing prep; refractory shock → MCS escalation; meningococcal purpura fulminans → emergent ICU + ID
    inputs: sbp, lactate, hr, temp
    actions: cardiogenic_shock, sepsis_bundle
    advance: Red flags screened + emergent intervention triggered if needed
  5. 5INITIAL_WORKUP
    Blood cultures × 3 BEFORE antibiotics, troponin, BNP, BMP, CBC, lactate, ABG, coags + DIC panel, LFT, ECG (q15-30 min serial during acute phase), bedside echo, CXR, urinalysis, lactate trend; throat swab if diphtheria suspicion
    inputs: blood_cultures, troponin, bnp_ntprobnp, cbc, ecg, echo, cxr, lactate
    actions: acs_pathway, panel.cardiac, panel.renal, panel.coag, panel.abg
    advance: Workup complete and empiric antibiotics started within 1 h of presentation
  6. 6BRANCHING_WORKUP
    Cardiac MRI (Lake Louise) for myocarditis confirmation; EMB if etiology uncertain or refractory shock; PCR for atypicals (Mycoplasma, Chlamydia, Coxiella); HIV test; PPD/IGRA + sputum AFB if TB risk; TEE if endocarditis suspicion (modified Duke); LP if meningococcal disease suspected
    inputs: cardiac_mri, hiv_test, ppd_or_igra
    advance: Etiology defined or EMB scheduled; targeted antibiotic regimen tailored within 48-72 h
  7. 7DIFFERENTIAL
    Bacterial subgroup identified (Staph vs Strep vs diphtheria vs TB vs meningococcal vs atypical); rule out viral (PCR), autoimmune (giant cell — EMB), drug-induced (clozapine, ICI), infiltrative (amyloid, sarcoid)
    inputs: blood_cultures, cardiac_mri
    advance: Etiology assigned or EMB pending
  8. 8RISK_STRATIFICATION
    SCAI 2022 CS stage; SOFA score; mixed septic + cardiogenic stage; CardShock registry score; transplant eligibility if refractory; quantify recovery probability
    inputs: sbp, lactate, troponin, creatinine
    advance: Stage documented + MCS / transplant eligibility documented
  9. 9TREATMENT
    TARGETED ANTIBIOTICS — empiric vancomycin 25-30 mg/kg load + ceftriaxone 2 g IV q24h (or piperacillin-tazobactam if HCAP risk) covers MSSA/MRSA/Strep/Listeria; tailor within 48-72 h to organism. Standard CS support: NE first-line; cautious dobutamine (arrhythmogenic in active myocarditis); IABP / Impella / VA-ECMO per SCAI staging. AVOID immunosuppression (worsens infection — distinct from autoimmune myocarditis). Diphtheria: equine antitoxin from CDC + erythromycin/penicillin. TB: 4-drug RIPE × 2 mo then RI × 4 mo + steroids if pericardial component. Meningococcal: ceftriaxone + dexamethasone (if meningitis component) + supportive. Vaccination boost contacts (diphtheria, meningococcal)
    inputs: sbp, creatinine, lft
    actions: protocol.cardiogenic_shock
    advance: Empiric antibiotics started + CS support active + targeted regimen plan documented
  10. 10DISPOSITION
    CICU for all bacterial myocarditis CS; ID isolation if TB / diphtheria / meningococcal; advanced HF / transplant team consult if refractory shock; cardiac MRI / EMB scheduled
    advance: Unit + isolation + multi-disciplinary team assigned
  11. 11MONITORING
    Continuous hemodynamics, daily lactate clearance, daily troponin + BNP trend, repeat blood cultures at 48-72 h to confirm clearance, daily BMP + LFT during antibiotics, vancomycin trough levels, AST/ALT during TB therapy, GDMT initiation if persistent EF<40 once euvolemic + off pressors ≥24 h
    inputs: troponin, bnp_ntprobnp, creatinine, lft, lactate
    actions: panel.cardiac, panel.renal
    advance: Monitoring cadence set + recovery trajectory documented
  12. 12FOLLOWUP
    Cardiology + ID follow-up at 1-3 mo; cardiac MRI at 3-6 mo for fibrosis assessment + recovery confirmation; vaccination updates (diphtheria booster q10y; pneumococcal; meningococcal if at-risk); GDMT continuation if persistent EF<40; cardiac rehab; contact tracing for diphtheria / meningococcal / TB
    advance: Follow-up booked + recovery confirmation imaging scheduled + contact tracing initiated