Cardiac conduction disturbances in Lyme disease.

A young patient is described presenting with third-degree atrioventricular block, who had a flu-like syndrome a few weeks before admission. The diagnosis of Lyme disease was suspected by serologic antibody detection and confirmed by Western immunoblot assay. Pacing was necessary because an unstable escape rhythm persisted. After treatment, atrioventricular conduction recovered. Lyme disease, a tick borne disease, is discussed with emphasis on cardiac involvement: atrioventricular block is a frequent complication of early disseminated disease. If treated with adequate antibiotic therapy, the prognosis is good.