Troubleshooting implantable cardioverter-defibrillator related problems

Since its introduction, now more than 20 years ago, the implantable cardioverter-defibrillator (ICD) has evolved from a non-programmable (committed) device into a sophisticated multi-programmable, multi-functional device with extensive diagnostic and therapeutic options. The more recent combination with cardiac resynchronisation therapy (CRT) further expanded its use to selected patients with severe symptoms of heart failure and left ventricular dyssynchrony at risk of sudden cardiac death. Whereas ICD technology developed rapidly, endocardial ICD leads, consisting of an integrated pace/sense and shock electrode positioned in the right ventricle, remained essentially unchanged after their introduction in the late 1980s, aside from a reduction in diameter. In the early years, ICD implantation was a major surgical procedure associated with significant morbidity and mortality, necessitating a thoracotomy to place the epicardial leads and patches and an abdominal incision to insert the bulky first generation device. With the introduction of endocardial shock electrodes and the significant reduction in size and weight of the devices, the complexity of the implantation procedure was reduced significantly and currently most systems can be implanted in the catheterisation laboratory by the electrophysiologist under local anaesthesia. However, compared to the relative ease of the current implantation procedure, follow-up and troubleshooting of ICD patients has become a much more complicated and challenging process, demanding extensive knowledge of cardiac electrophysiology as well as a thorough understanding of the different features and algorithms incorporated in modern (CRT) ICDs. Combined with the increasing number of ICD patients, troubleshooting of ICD related problems has become a challenging task. In this overview some of the most important device related problems will be discussed. Device related problems in ICD patients may vary from relatively simple sensing or pacing problems to life threatening episodes of inappropriate shocks or failure of shock delivery. In analysing and solving ICD related problems, it is …