HIGH-RESOLUTION, 3-DIMENSIONAL FLUORESCENT IMAGING REVEALS MULTILAYERCONDUCTION PATTERN IN THE ATRIOVENTRICULAR NODE

Background-The atrioventricular node (AVN) is the only normal electric al link between the upper and lower chambers of the heart. The AVN mod ulates transmission of impulses, thus coordinating the contraction of the atria and ventricles, Methods and Results-Structural and functiona l complexity, combined with the absence of adequate experimental techn iques, has complicated attempts to directly evaluate the three-dimensi onal electrical activity of the AVN, Thus, despite a century of resear ch by conventional electrophysiologic and histologic methods, even the existence of conduction through AVN is still debated. Conclusions-Usi ng a novel combination of microelectrode recordings and high resolutio n fluorescent imaging with voltage-sensitive dyes, we have for the fir st time clearly demonstrated three-dimensional conduction through the AVN.