Infectious - Inflammatory

Myocarditis

  • Inflamed myocardium (heart muscle) usually from an infection that often affects younger pts (40's is younger)

PATHO

  • Viral or BX infxn

    • Coxsackievirus ➔ Hand, Foot & Mouth dz

    • Lyme

    • MCC worldwide: Chagas disease by Trypanosoma cruzi

    • Parvovirus B19 ➔ 5th dz

    • Group A β hemolytic Strep ➔ acute rheumatic fever

    • Cornybx diptheriae

    • Mycoplasma/bx

  • Systemic

    • SLE, vasculitis, sarcoidosis

  • Toxins

    • Sulfonamides, clozapine (2nd gen antipsych), chemo, etOH, radiation, CO, spider venom

SSX

  • Trypanosoma cruzi (protozoan) ➔ mega-esophagus/colon & myocarditis

  • Lyme carditis ➔ heart block

DX

  • Endomyocardial biopsy via cardiac cath (if other diagnostics are inconclusive)

    • Lymphocytic infiltration with necrotic myocardium points to viral cause

  • EKG will be ugly but no MI

  • CXR/ECHO show enlarged heart/dilated cardiomyopathy

  • ↑ cardiac enzymes, ESR, BNP,

  • EKG likely shows sinus tach, or tachy resulting from foci within sick myocardium

    • Repolarization abnormalities will be present throughout

    • MI has repolarization abnormalities in specific-neighboring leads, Q waves, and completely lost R waves

TX

  • Admit for monitoring and rest

  • TX the infection (ABX, antimycotic)

  • TX the HF (ACEi/β-blockers/diuretics)