Preload and Autonomic Responses With Cardiac Neuromodulation Therapy (CNT) (CS-06)

Subjects indicated for a dual chamber pacemaker implant or replacement who are not 100% dependent on right ventricular pacing may be eligible to participate in the study. This investigation will evaluate the effect of RV pacing lead position on cardiac function and the modulation of the autonomic nervous system using Cardiac Neuromodulation Therapy (CNT) pacing signals at different positions of the RV pacing lead. A standard conductance catheter will be introduced through the femoral artery and advanced into the left ventricle to measure cardiac volumes and pressure. Arterial blood pressure will be measured from the other femoral artery with an additional sheath. The Moderato® IPG will be used to generate Cardiac Neuromodulation Therapy (CNT) signals and deliver them to the patient through the cable and leads. A range of CNT signal parameters will be used to assess the effect on sympathetic activity at different positions of the RV pacing lead. Ventricular pressure and volume readings from the conductance catheter and arterial pressure readings will be recorded and analyzed to assess the effect of CNT signals on cardiac function, sympathetic activity and blood pressure. The effects of CNT signal over a range of parameter settings will be studied for the different RV lead positions.