[Serious arrhythmias in Borrelia infections].

Carditis is seen in about 4-10% of cases of Lyme's disease. It is usually dominated by varying degrees of atrioventricular block, and implantation of a temporary pacemaker may be necessary. Ventricular and supraventricular tachycardias seem to be less frequent than block, and as far as we know ventricular tachycardia provoked by bradycardia has not been reported previously. Third degree AV-block after oral penicillin treatment of erythema migrans is unusual in Europe. When an atrioventricular block of unknown origin is diagnosed, Lyme carditis must be considered, especially among young patients.