9. Pacemakers: Clinical Results, Practical Aspects and Late-Break Clinical Trials

Objectives The efficacy of the Far-Field Signal Reduction (FSR) leads, based on optimization of the tip-to-ring electrode spacing and surface areas, has been demonstrated by chronic animal studies and acute human testing. This study, for the first time, was designed to evaluate the chronic sensing and pacing performance of FSR leads on pacemaker patients. Methods 60 patients were randomized to either a FSR lead or a standard pacing lead (SJM Tendril1688T) at implant with a dual chamber SJM Identity™ or ADx pacemaker. The majority of the right atrial leads were placed at the RAA. Standard pacing/sensing measurements and a far field signal sensing threshold testing were conducted for each patient at implant, prior to hospital discharge, and at 10-day, 40-day, and 90-day post implant follow-up, respectively. Results There are no adverse events during the entire study. On the average of the 90 day follow up, about 74% of the FSR patients versus 41% of the control group demonstrated a far field R-wave signal below 0.1 mV. The mean bipolar pacing threshold, P-wave amplitude, and impedance of FSR leads at 90-day post implant were 2.4mV, 0.6V, and 403Ω, respectively. Conclusions The FSR leads in the right atrium of standard pacemaker patients performed safely achieving a significant far field signal reduction throughout the 90 day follow up. The FSR leads' overall sensing and pacing performance was satisfactory.