Optical imaging of cardiac transmembrane potential in dye-stained tissue is an emerging technique in cardiac electrophysiology. Despite its widespread application to studies of isolated hearts, it has been applied traditionally to recording only a single view that presents the potential distribution of a fraction of the cardiac surface. This poses a significant limitation in studying whole heart electrophysiology, particularly when large-scale phenomena such as fibrillation and defibrillation are of interest. We have developed a panoramic imaging system based on a high-speed charge-coupled device camera with a maximum imaging speed of 335 frames/s at 128x64 pixels/frame. Our system provides one front view and two back mirror views of isolated hearts, thus extending optical imaging capabilities to record from the entire three dimensional heart surface with only one camera.