Accurate measurement of cardiac activities with high spatiotemporal resolution in three-dimensional(3D)heart tissues is important for investigations ranging from fundamental biophysical studies of 3D tissue and 3D tissue models for in vitro drug testing to implants that replace diseased and/or damaged heart tissue.Despite this broad-ranging importance,large-scale spatiotemporal mapping of cardiac action potentials(APs)has been largely restricted to two-dimensional recording.Recently,our group has developed 3D macroporous nanoelectronic scaffolds1,2 to create cyborg heart tissues,where networks of nanoelectronic devices seamlessly interfacing with synthetic 3D tissues.Here,we demonstrate the capability to realize spatiotemporal mapping of APs in cyborg heart tissues and reveal the effects of drugs and electrical stimulation on the 3D APs conduction circuitry.Specifically,subcellular spatial resolution(1-10 m)and 0.02 ms time resolution have been achieved to monitor fast electrophysiology activities in normal and drug modulated cyborg heart tissues,demonstrating the power of our approach in fundamental electrophysiological and pharmacological studies.Significantly,we have detected characteristic arrhythmia symptoms in cyborg heart tissues and actively regulated the arrhythmia by electrical stimulation through nanoelectronic networks.These results and studies demonstrate the potential and are expected to open up a new era of cyborg tissue enabled disease diagnostics and electronic therapeutics.