Abstract
We have developed various optical mapping systems to visualize the electrophysiological events in rabbit hearts. We stained Langendorff perfused rabbit heart with voltage sensitive dye di-4-ANNEPS (0.2 μM) added to Krebs Ringer solution. We illuminated the heart by Bluish green LED (Center of emission wavelength is approximately 500 nm). Shifts of Fluorescence spectra of the dye depending on action potential is converted into optical signal intensity by collecting the fluorescence signals through longpass filter (cut off wavelength: 600nm), The current system can visualize electric excitation wave on epicardium with temporal resolution up to 0.5 ms and spatial resolution of 0.05mm. We developed an endoscopic optical mapping system to visualize the excitation propagation on endocardium. We demonstrated simultaneous optical measurement of the excitation propagation of the epicardium and endocardium of the right ventricle wall of Langendorff perfused rabbit heart. We could also visualize excitation propagation on surface perfused excised tissue from right atrium containing sinus node with temporal resolution of 1ms.
