84 www.fmc.viamedica.pl ORIGINAL ARTICLE

Reduction of defibrillation threshold and safety of usage of a new model of subcutaneous defibrillation lead This study was designed to evaluate the performance of a new single coil model of a subcutaneous defibrillation lead (Medtronic, 6996S) by assessing its capability to lower the defibrillation threshold. The 6996S lead is a permanent unipolar subcutaneous lead with a short (15 cm) defibrillation coil. Additionally, the safety of the lead and its chronic stability were evaluated. The investigation was performed in patients who underwent implantation of an ICD system consisting of a single coil RV lead with a left sub-clavicular Active Can ICD. In these patients, the DFT was determined twice during the implantation procedure with a binary search protocol, once with an ICD system which included the 6996S lead (RV → Can + SQ), and once without the 6996S lead (RV → Can). The order in which the implanted system configurations were tested was randomised. Between June 2004 and February 2006, 32 patients were enrolled into the study. Post-implantation follow-up was of at least three-month duration. The DFT test results of 31 patients have been analysed. The averag