Graphene Biointerface for Cardiac Arrhythmia Diagnosis and Treatment

Abstract

Heart rhythm disorders, known as arrhythmias, cause significant morbidity and are one of the leading causes of mortality. Cardiac arrhythmias are primarily treated by implantable devices, such as pacemakers and defibrillators, or by ablation therapy guided by electroanatomical mapping. Pharmacological treatments are mostly ineffective. Both implantable and ablation therapies require sophisticated biointerfaces for electrophysiological measurements of electrograms and delivery of therapeutic stimulation or ablation energy. In this work, we report for the first time on graphene biointerface for in vivo cardiac electrophysiology. Leveraging sub-micrometer thick tissue-conformable graphene arrays, we demonstrate sensing and stimulation of the open mammalian heart both in vitro and in vivo. Furthermore, we demonstrate graphene pacemaker treatment of a pharmacologically-induced arrhythmia, AV block. The arrays show effective electrochemical properties, namely interface impedance down to 40 Ohm×cm2, charge storage capacity up to 63.7 mC/cm2, and charge injection capacity up to 704 µC/cm2. Transparency of the graphene structures allows for simultaneous optical mapping of cardiac action potentials and calcium transients while performing electrical measurements and stimulation. Our report presents evidence of the significant potential of graphene biointerfaces for the future clinical device- and catheter-based cardiac arrhythmias therapies.

Soft, bioresorbable, transparent microelectrode arrays for multimodal spatiotemporal mapping and modulation of cardiac physiology

“…Studies on rat and human hearts highlight the function, form factor, durability, and capability of the devices for (i) colocalized multiparametric spatiotemporal electrical/optical mapping of critical cardiac physiological parameters, such as heart rhythm, biopotentials, oxygenation, metabolic state, calcium homeostasis, activation propagation pattern, and myocardial conduction and contraction and (ii) real-time demand-based site-specific cardiac pacing to control the propagations of cardiac waves and provide therapeutic solutions such as treating bradycardia and atrioventricular (AV) block on soft heart tissue surfaces. We would like to note that alternative pacing technologies, such as optogenetic or nongenetic optical pacing of the hearts, have also been widely used in cardiac research (29)(30)(31)(32)(33)(34)(35). Optogenetics is a promising optical pacing method that uses light-activated ion channels to control cardiac activity.…”