DF-4 Lead Connector: Innovative Technology, Unexpected Problems and Novel Solutions

Implantable cardioverter defibrillator (ICD) technology has evolved from the surgical thoracotomy based device systems in 1980 to only transvenous lead based systems in 1990s to subcutaneous ICD systems more recently. As far as transvenous lead based ICD systems are concerned, major advancements have occurred that include decrease in ICD device size and use of biphasic shock waveform. Many software and algorithmic developments have redefined optimization of defibrillation waveform, supraventricular-ventricular tachycardia discriminators, avoidance of unnecessary right ventricular pacing, delivery of anti-tachycardia pacing during charging etc.. However, not all of the technological advances accepted for clinical use have been trouble free. Use of newer ICD lead designs with reduced caliber resulted in unanticipated problems like lead fracture or insulation failure in some of them warranting their recall [1]. Another recent advancement in the lead design is the development of DF-4 technology. The traditional DF-1 lead design has bi/trifurcated lead connectors that integrate in to a single lead body through a yoke. Use of the newer DF-4 ICD lead technology has simplified the implant process to some extent and has certain other advantages.