POTD: Lyme Carditis

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Lyme Carditis 

Lyme disease is caused by the spirochete Borrelia burgdorferi, transmitted by the Ixodes tick. Mostly in 2 regions:

  1. Northeast (Mid-Atlantic and New England states), and

  2. North Central (Wisconsin and Minnesota)


This pearl will focus specifically on lyme carditis and not other clinical manifestations of lyme. 


3 phases of the disease:

1) early localized 

2) early disseminated

3) late 

lyme phases.png

Lyme carditis occurs in 1% of patients with lyme and during the early disseminated phase. This is typically 1-2 months after infection. 



Symptoms

  • lightheadedness

  • syncope

  • shortness of breath

  • palpitations

  • chest pain


What's going on?

  • Causes AV conduction abnormalities that can vary rapidly; so a person can go from a first degree block to complete AV nodal block within minutes! They can also revert back within minutes.

  • Highest risk for progression to complete block is PR > 300

  • Can cause a myopericarditis that is self-limited

  • Sudden cardiac death has been reported



Diagnosis

  • Need positive lyme serologies -- ELISA and confirmatory Western blot

  • These tests can test for IgM, but this gives higher false positives. Since lyme carditis occurs during the early disseminated phase, it is better to screen for lyme IgG

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Management

  • Patients with PR > 300 should be hospitalized, given IV antibiotics and monitored with tele

  • Ceftriaxone 2g/day IV in adults (50-75mg/kg/day IV in children)

  • When PR becomes < 300, can switch to oral antibiotics (doxycycline 100mg BID, amoxicillin 500mg TID, or cerfuroxime 500mg BID)

  • Need a total of 21-28 days of antibiotic therapy



*It should be noted that chronic lyme disease has come to refer to an entirely different entity: https://www.nybooks.com/daily/2018/07/25/the-challenge-of-chronic-lyme/ 



Happy hiking!