[Sinoatrial and atrioventricular conduction disorders in Lyme disease. Apropos of 2 case reports].

Lyme's disease due to Borrelia Burgdorferii is a rare cause of acute atrioventricular block (AVB) which is the commonest cardiac complication. Cutaneous, neurological and articular involvement complete the clinical picture of this condition. These two cases, confirmed by serology, support previously reported data describing the favourable prognosis of these conduction defects (suprahisian and/or hisian in our 2 cases) which regress completely, irrespective of their degree of severity. The authors also describe AVB occurring without extracardiac manifestations of this condition and a documented case of sinoatrial block, indicating a new zone of infestation.