Can incremental innovation of implantable cardioverter-defibrillator systems become disruptive to patient care? Moore's law gone awry.

摘要

Implantable cardioverter-defibrillator (ICD) implantation has evolved from a thoracotomy approach, with shock patches attached to the epicardium, to a more limited thoracotomy using a subxiphoid approach, and finally to the endocardial insertion of pacing and shock leads with prepec-toral insertion of the ICD generator similar to a pacemaker. In the mid-1990s, there was a period of time when leads could be endocardially placed, yet the ICD generators were too large (4-7 times the size and weight of today's generators) for a pectoral approach implant. To take advantage of endocardial leads, ICD generators were implanted above the rectus sheath muscles, and the pacing and shock leads were tunneled from the subclavian or cephalic vein insertion site, subcutaneously to the ICD generator site. Over 10 years later, many of these patients are still alive and undergoing their second or third ICD generator replacement for end-of-life indications. Most original implants utilized dual lead shocking coils, predating active can technology. Given the fact that these lead systems are still intact, replacement of just the ICD generator without a whole new lead system is preferred.