Entrapment of a tined lead by the chiari network with preserved atrial sensing ability in a patient with atrioventricular block: a case report.

An 82-year-old woman with 2:1 atrioventricular block underwent a pacemaker implantation procedure, but a tined lead became entrapped by the Chiari network. All manipulations failed to achieve release of the electrode, by which the atrial electrical potential could be recorded. Tines equipped near the tip of a pacemaker lead are intended to prevent dislodgment, but entrapment of the tined tip by intracardiac structures is probable.