Abstract: Re-entrant arrhythmias—the leading cause of sudden cardiac death—are caused by diseased myocardial tissue and consequent delayed myocardial conduction. Access to the coronary veins that cross the “culprit” scar regions where re-entry originates can provide improved pacing to these delayed regions, offering a novel opportunity to prevent ventricular arrhythmias. However, there are no pacing electrodes which are small enough to navigate these tributaries. To address this need, we have developed an injectable conductive hydrogel that can fill the epicardial coronary veins and their mid-myocardial tributaries. When connected to a standard pacing lead, these injected hydrogels can be converted into flexible electrodes that directly pace the previously inaccessible mid-myocardial tissue. Successful in vivo deployment demonstrated that the hydrogel electrode filled the anterior interventricular vein with extension into the septal (mid-myocardial) venous tributaries to depths far more distal and refined than any current technologies allow. In addition to successful capture and pacing of the heart, analysis of surface ECG tracings revealed a novel pacing observation highly specific for and suggestive of capture of extensive swaths of septal myocardial tissue. In vivo cardiac electroanatomical mapping studies in an ablation scar model showed uniform capture along the hydrogel in the vessels as well as increased capture area compared to point pacing. Collectively, these findings demonstrate that this injectable hydrogel electrode can be deployed to scarred regions of the heart to provide a reliable pacing modality that most closely resembles native conduction with the potential to eliminate delayed myocardial conduction and associated re-entry.
Bio: Elizabeth Cosgriff-Hernandez, Ph.D. is a Professor of Biomedical Engineering at The University of Texas at Austin and holder of the Cullen Trust for Higher Education Endowed Professorship in Engineering. Her laboratory specializes in the development of polymeric biomaterials to improve clinical outcomes of medical devices and regeneration strategies. She also serves on the scientific advisory board of ECM Biosurgery and Rhythio Medical as well as a consultant to several companies on biostability evaluation of medical devices. Dr. Cosgriff-Hernandez is an Associate Editor J. Mat. Chem. B and Fellow of the International Union of Societies for Biomaterials Science and Engineering, Biomedical Engineering Society, Royal Society of Chemistry, and the American Institute for Medical and Biological Engineering. She has previously served as an Associate Editor of J. Biomed. Mat. Res., Part B and chair of the NIH study section on Musculoskeletal Tissue Engineering.
Host: Professor Shelby Hutchens