High spatial-temporal resolution optical mapping of cardiac membrane action potentials using high intensity light emitting diodes and high spee3 digital video cameras

点击翻译按钮获取中文摘要

We have developed a High spatial-temporal resolution optical mapping system of cardiac membrane action potentials using high intensity light emitting diodes and high-speed digital video cameras. A rabbit heart perfused in a Langendorff apparatus was stained with voltage sensitive dye : di-4-ANEPPS.Central wavelength of emitted fluorescence changes depending on membrane action potential. Thus by monitoring the emitted fluorescence from the perfused heart through optical long-pass filter, we can obtain membrane action potential information as change in fluorescence intensity at each point on the tissue. High intensity bluish green light emitting diodes were used as an excitation light source. Since it is a solid-state light source, it is easy to handle. Its intensity can be stabilized electronically. As a measurement device, We used high-speed digital video cameras that can capture images every 0.25 msec. We used it at frame rate of 1125 frames per second or 750 frames per second. As a r … More esults, high signal to noise ratio was obtained. Its spatial resolution was approximately O.2 mm. And its temporal resolution was 1 msec. Developed system can provide high resolution of measurement both for spatial resolution and temporal resolution while keeping relatively high signal to noise ratio (2.35 as an average) compared with conventional optical mapping system of cardiac action potentials. We also developed a software to process larga amount image data to obtain action potential information at any observation point on the heart tissue. In order to enlarge the observable area by the system, two high speed digital video cameras were used simultaneously. Compared with a single camera system, the double camera system could track the complicated excitation propagation pattern such as meandering of spiral wave and break up of the excitaion front. In conclusion, the developed high spatial-temporal resolution optical mapping system was effective in analyzing complicated electrical excitation pattern during arrhythmia. Less