Lyme Carditis

Article by Lindsey Breinager, MD
Follow Up Rounds 12/8/2017

The Case

CC 31M, syncope x 1 just prior to presentation

Vitals Afebrile, HR 48, BP 133/65, RR 17, O2 Sat 100% on RA

Well appearing young man, physically fit, NAD
HEENT: eomi, perrl, no JVD, NCAT
CV: normal s1, s2, no audible murmurs, slightly bradycardic
PULM: clear breath sounds b/l; no chest wall tenderness, normal respiratory effort
ABD: soft, ntnd, bs+
EXT: wwp, no edema, pulses 2+
NEURO: AOx3, 5/5 motor throughout in upper and lower extremities, sensation grossly intact, CN ii-xii grossly intact, gait wnl, normal ftn

Labs

CXR No acute cardio/respiratory findings

Pt began to feel light-headed again. ECG repeated:

Interventions

Patient admitted to camping trip in upstate NY, but denied hx of insect bite or rashes
5 mg atropine with some improvement in HR and symptoms
TVP placed
Admitted to the CCU
2g IV Ceftriaxone daily started for presumptive treatment of Lyme disease
Pt improved heart rate and rhythm normalized; TVP pacer removed by day 5
Transitioned to PO doxycycline for total of 21 day course

Borrelia Burdorferi (spirochete) from ixodes tick
Less than 1/3 affected recall bite
Early localized disease: after 1 week incubation
- EM in 90% of pts
- Constitutional sx
- GI upset
- Arthralgias, myalgias
Early disseminated: after 4 weeks
- Neurologic: 15% of pts CN palsies (VII common), meningoencephalitis
- Cardaic: 4-10% of untreated pts
  - AVB of varying degrees, tachydysrythmias, myopericarditis, ventricular impairment
- Ophthalmic: conjunctivitis, keritits, optic neuritis
Late Lyme
- Long term relapsing arthritis
- Chronic encephalopathy
Diagnosis
- Often by clinical and epidemiological features
- Lab studies and cultures are often of low yield
  - IgM peaks between 3-6 weeks
  - IgG detectable after 2 months
  - ELISA w/ sensitivity of 90%
Treatment
- Early localized disease:
  - Men, non-pregnant and non-lactating women and children >8 yrs
    - Oral doxy x14 to 21 days
  - Pregnant women and children <8yrs
    - Amoxicillin
- Early disseminated depends on manifestations
  - Neurologic w/ normal CSF
    - PO doxy or amoxicillin x30 days
  - Neurological w/ meningoecelphalitis
    - IV ceftriaxone x 28 days
  - Cardiac
    - IV ceftriaxone until normalization of manifestations and transfer to po medication for total of 21-28 days
- Late disease
  - Controversial

Peter Gruber says:

December 16, 2017 at 2:30 am

How can I blow this case? 1- Not ordering a second ecg when the pt became light headed and missing AV dissociation 2- not asking about risk factors for Lyme and missing the etiology and treatment of syncope. However, the first ecg by itself had enough concerning findings to not send this pt home. A heart rate of 41 in an awake pt makes me nervous and is suggestive of arrhythmia related syncope as per at least theEuropean Society of Cardiology. Although first degree heart block is most commonly seen as a condition of increased vagal tone or medications and is benign, it may represent underlying cardiac pathology that affect the node such as Lyme carditis and sarcoidosis. We generally do not consider first degree block to be concerning but in the context of syncope, significant bradycardia and also a prolonged QT, it should be considered as potentially indicative of cardiac pathology.

It was a good pickup to ask about risk factors for Lyme in a pt with syncope and an AV block. AV block is the most common objective feature of Lyme carditis. Although first degree block is not a true block- it is a delayed or slowed AV conduction, it often rapidly progresses to 2nd degree or complete heart block in Lyme carditis