A previously healthy Caucasian 22-year-old man presented to a southern Quebec community hospital with syncopal episodes for 1 week. He was found to be hypotensive and bradycardic (heart rate 36 beats per minute), owing to third-degree atrioventricular (AV) block, which did not respond to atropine. A perfusion of isoprenaline was started, and the patient was transferred to a tertiary care center in Montreal.
The patient denied any recent travel history outside the province of Quebec. However, the patient frequently visited deeply wooded areas and was in close contact with deer and other wildlife.
On arrival, skin examination was remarkable for multiple diffusely distributed erythematous patches with central clearing, consistent with erythema chronicum migrans (Figure). The remainder of the physical examination was unremarkable.
On the basis of the history and physical examination, a diagnosis of early disseminated Lyme disease with carditis was suspected, and ceftriaxone was started. Screening Lyme serology was positive, and the blood smear was negative for Babesia/Anaplasma spp. The patient’s rash completely resolved within 24 hours of antibiotic initiation.
The transthoracic echocardiogram showed mild nonspecific mitral valve thickening and an ejection fraction of 60%. There were no other echocardiogram abnormalities. After 48 hours of observation, he underwent a temporary VVI (ventricular pacing and sensing mode) pacemaker insertion.
On ceftriaxone, the AV block converted to first degree 2 days after starting antibiotics and then completely resolved by day 11, at which point the pacemaker was removed. He completed a total 21-day course of treatment with oral doxycycline. Western blot testing for Lyme disease was positive, confirming the diagnosis.
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-Samuel De l’Étoile-Morel, MD, Abeer Feteih, MD, Catherine Anne Hogan, MD, MSc, Donald C. Vinh, MD, George Thanassoulis, MD, MSc
This article originally appeared in the August 2017 issue of The American Journal of Medicine.
