Multi-Axis Lead with Tetrahedral Electrode Tip for Cardiac Implantable Devices: Creative Concept for Pacing and Sensing Technology.

Abstract Background We developed a multi-axis lead (MaxLead) incorporating four electrodes arranged at the lead-tip organized in an equidistant tetrahedron. Here, we studied MaxLead performance in sensing, pacing and activation wavefront-direction analysis. Methods Sixteen explanted animal hearts (from 7 pigs, 7 sheep and 2 rabbits) were used. Pacing threshold was tested from all axes of MaxLead from RV apex before and after simulated dislodgement. Additionally, conduction-system pacing was performed in sheep heart preparations from all axes of MaxLead. Sensing via MaxLead positioned at RV apex was tested during sinus rhythm (SR), pacing from RV and LV free-wall, and ventricular fibrillation (VF). MaxLead-enabled voltage (MaxV), defined as the largest span of the sensed electric field loop, was compared to traditional lead-tip voltage detection. Results Pacing: MaxLead minimized change in pacing threshold due to lead-dislodgement (average voltage change 0.2 mV, 95% CI (-0.5, 0.9)), using multiple bipoles available for pacing. In animals with high conduction system pacing thresholds (>2mV) in one or more bipoles (3/7), acceptable thresholds ( Conclusions The multi-axis MaxLead electrode showed advantages in pacing, sensing and mapping and has the potential to allow for improvements in lead/electrode technology for cardiac implanted electronic devices.