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Lyme Carditis

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Lyme Carditis, Borrelia Myocarditis

  • See Also
  1. Lyme Disease
  2. AV Block
  3. Myocarditis
  4. Secondary Cardiomyopathy
  5. Infectious Pericarditis
  • Pathophysiology
  1. Lyme Carditis is a second stage (early disseminated) Lyme Disease complication
    1. Spirochete infection with inflammation that damages cardiac tissue
  2. Follows Tick Bite by 4-6 weeks, and the intervening Erythema Migrans rash (early localized)
  3. Other second stage (early disseminated) lyme may also present with Facial Nerve Palsy (Bell Palsy)
  • Findings
  1. Atrioventricular Block (AV Block, most common manifestation)
    1. May range from first degree AV Block to higher grade, second and third generation AV Block
  2. Less common presentations
    1. Myocarditis
    2. Pericarditis
  • Symptoms (variably present)
  1. Dyspnea
  2. Chest Pain
  3. Palpitations
  4. Syncope
  • Labs
  1. See Lyme Disease
  • Diagnostics
  1. Electrocardiogram (EKG)
    1. Myopericarditis findings may be present
    2. Atrioventricular Block (AV Block) >200 ms
      1. Admit patients with acute first degree AV Block >300 ms
      2. Observe for progression to higher AV Blocks (second or third degree AV Block)
  • Management
  1. Consult Cardiology
  2. Initiate Antibiotics
    1. Ceftriaxone IV daily
      1. Continue until cardiac stabilization AND PR Interval <300 ms
    2. Transition to oral Doxycycline (or alternatives) for 14 to 21 days
      1. See Lyme Disease for treatment protocols
  3. New AV Block
    1. Typically resolves with Lyme Disease treatment
    2. Temporary Pacemaker placement may be needed
  4. Other uncommon complications
    1. Myopericarditis
  • References
  1. Carvey (2025) Crit Dec Emerg Med 39(12): 4-12
  2. Shen (2022) Infect Dis Clin North Am 36(3):553-61 +PMID: 36116834 [PubMed]