Cardiovascular Implantable Electronic Devices -> Leads & Electrodes: -> Technology D-AB06 - Cardiac Resynchronization - LV and His Bundle Pacing! (ID 25) Abstract

D-AB06-01 - Conductive Hydrogels As Injectable Electrodes Via Epicardial Vessels And Tributaries (ID 772)


Background: Traditional pacemaker leads with single point myocardial contact cannot access midmyocardial regions that sustain VF, thus limiting their utility in creation of “virtual electrodes” for imperceptible defibrillation. An injectable electrode with in situ cure will expand pacing to reach previously inaccessible areas by converting small coronary venous tributaries into flexible extensions of pacemaker leads.
Objective: Achieve pacing using an injectable electrode that can be delivered via catheter with rapid in situ cure.
Methods: The injectable electrode is a conductive hydrogel in which silver nanoparticles (5.5 wt%) were added to a poly(ethylene glycol) based hydrogel system (10 wt%, 35kDa). The hydrogel precursor solutions, one with ammonium persulfate and one with iron gluconate, were injected using a dual lumen catheter (Fig. 1A) into the anterior interventricular vein (AIV) epicardially in two acute porcine models. X-ray confirmed delivery and retention in the AIV. The cured hydrogel was excised post-mortem to confirm gelation upon mixing of the two components. Temporary pacing wires were used to provide pacing via the hydrogel.
Results: Successful filling of the AIV and small tributaries with the injectable electrode was confirmed with contrast under x-ray. Gross examination of the excised hydrogel (Fig. 1B) indicated rapid gelation following catheter delivery. Capture was confirmed in ECG upon pacing at 120 BPM with 2mA (Fig. 1C).
Conclusion: This injectable electrode is a promising platform technology to expand current pacing capabilities. Future studies will evaluate the extent of capture and optimize hydrogel properties for long-term pacing applications.