Fig. 1.

Summary of the high resolution optical mapping system with automated analysis. A represents the schematic of the optical mapping system. The LA samples were excited by four 530 nm LEDs, and filtered through a high NA objective and a 630 nm long pass filter. The electrodes were used for programmed stimulation at 300–80 ms pacing cycle lengths. Images were captured at a frame rate of 1000–2000 per second and recorded on a desktop computer for analysis using Winfluor software. The images above were recorded at 1000 frames per second. The electrodes can be seen on the upper left of the atrial image with the line of activation indicated by the black arrow. The action potentials indicate the time at which the signals have reached that region. B This displays the outcome of an averaged signal taken from the left atrium stimulated at 100 ms CL (with standard errors. Adjacent, is the same signal with its action potential durations labelled at APD30, 50 and 70 with the start of activation indicated by dF/dtmax shown. C The isochronal map is a colour scale of the time taken to activate at each pixel, from the same atrium as above at 100 ms CL. The time increases in the direction opposite to where the electrodes are placed. D Conduction vectors that indicate the direction of the wave are generated from the activation map.