[Complete transitory atrioventricular block in Lyme disease].

Cardiac manifestations in Lyme disease are uncommon and could generate myocarditis and/or pericarditis, but the most frequent and typical cardiac manifestation is in the form of conduction system disorders, causing blocks, which, according to their location and degree, could be intraventricular, intraatrial or atrioventricular of first, second or third degree. We report a case of transient atrioventricular block in a patient with frequent tick bites and with a positive serologic test for Borrelia burgdorferi.