Instantaneous lead entrapment: an unusual complication of nonthoracotomy implantation of an endocardial defibrillation lead.

Nonthoracotomy implantation of implantable cardioverter defibrillators is performed with transvenous leads that are similar to pacemaker leads and are subject to the same potential problems. We report an unusual complication of lead placement in which an electrode immediately became entrapped in the superior rim of the tricuspid valve, resisting all efforts at removal.