Protocol for high-resolution optical mapping of ex vivo rat heart for electrophysiological studies

Cardiac optical mapping provides high-resolution spatiotemporal insights into cardiac electrophysiology. Here, we present a protocol for capturing electrical signals in rats using voltage-sensitive dyes and blebbistatin to inhibit muscle contractions. We describe steps for aortic cannulation, heart isolation, optical mapping, and detailed signal analysis. This staining strategy utilized in this protocol allows for precise signal recording while minimizing motion artifacts, thereby enhancing image quality on the cardiac surface. For complete details on the use and execution of this protocol, please refer to Hu et al.¹.