[Atrioventricular crosstalk with unipolar leads: a cause of ventricular asystole and syncope].

In this article, we describe a case of ventricular asystole in a patient implanted with a cardiac pacemaker. The patient had a device replacement. The new pacemaker has been connected to old unipolar leads. The detection has been, inadvertently, programmed in a bipolar mode. This programmation induced an inhibition of the atrial and ventricular pacing due to oversensing of myopotentials. An inhibition of ventricular stimulation has been recorded also because of ventricular detection of the unipolar atrial stimulation (atrioventricular crosstalk). Lack of ventricular stimulation induced in this dependant patient ventricular asystole and syncope.