Reversible Heart Block in Lyme Disease: Canadian Case Report
Lyme disease can affect the heart and, in some cases, cause serious conduction abnormalities. A case from Canada highlights reversible complete heart block as a manifestation of early disseminated Lyme disease.
This raises an important question: can Lyme disease cause severe heart block in otherwise healthy individuals? In some cases, infection-related inflammation of the cardiac conduction system may lead to high-grade atrioventricular block.
“A previously healthy 22-year-old male presented with syncopal episodes for one week,” according to De l’Étoile-Morel from McGill University Health Centre. He was hypotensive and bradycardic, with a heart rate of 36 beats per minute due to third-degree atrioventricular block that did not respond to atropine. Cardiac echocardiography was unremarkable.
The patient had multiple diffusely distributed erythematous patches with central clearing, consistent with early disseminated Lyme disease. Lyme serology was positive, while testing for Babesia and Anaplasma was negative.
He had no travel outside Quebec but reported significant exposure to wooded areas and wildlife.
Cardiac Conduction Improved with Antibiotic Treatment
After 48 hours of monitoring, a temporary pacemaker was placed. Following initiation of intravenous ceftriaxone, the atrioventricular block improved to first-degree block within 2 days and resolved completely by day 11, allowing removal of the pacemaker.
The patient completed a 21-day course of therapy with oral doxycycline. Follow-up Western blot testing was positive for Lyme disease.
Early Recognition May Prevent Complications
This case illustrates a potentially reversible cardiac complication of Lyme disease, where prompt recognition and treatment can lead to recovery without permanent pacing.
Patients presenting with unexplained heart block, particularly in endemic areas, may warrant evaluation for Lyme disease. Early identification may reduce the risk of invasive interventions and prolonged cardiac complications.
Patients may benefit from review of Lyme disease symptoms, assessment of testing accuracy, and awareness of cardiac manifestations such as Lyme carditis.
Follow-Up Considerations
Follow-up may be appropriate to monitor for potential long-term complications, including neurologic involvement or persistent symptoms after treatment.
References
- Koffi JK, Savage J, Thivierge K et al. Evaluating the submission of digital images as a method of surveillance for Ixodes scapularis ticks. Parasitology (2017).
- De l’Etoile-Morel S, Feteih A, Hogan CA, Vinh D, Thanassoulis G. A Case of Reversible Complete Heart Block. Am J Med (2017).
- Logigian EL, Kaplan RF, Steere AC. Chronic neurologic manifestations of Lyme disease. N Engl J Med (1990).
- Logigian EL et al. Lyme encephalopathy treatment. J Infect Dis (1999).
- Fallon BA et al. IV antibiotic therapy trial. Neurology (2008).
- Aucott JN et al. PTLDS cohort study. Clin Vaccine Immunol (2016).
- Weitzner E et al. Long-term Lyme outcomes. Diagn Microbiol Infect Dis (2016).
Dr. Daniel Cameron, MD, MPH
Lyme disease clinician with over 30 years of experience and past president of ILADS.
Symptoms • Testing • Coinfections • Recovery • Pediatric • Prevention
