Modeling the functional role of SA node-atrial interdigitation

Recent immunohistochemical studies in which atrial and sino-atrial (SA) node tissue from the guinea-pig heart has been labeled differentially with fluorescent markers show that fine strands of atrial tissue penetrate into, and interdigitate with SA node cells in the primary pacemaker region. Computational models of the SA node-atrial network were implemented on the parallel CM-5 supercomputer and used to investigate the functional role of this interdigitation. Simulation results show that interdigitation of SA node and atrium reduces electrotonic loading effects of the atrium on the node, and improves reliability of conduction of the nodal pacemaker potential into the surrounding, highly coupled atrium.<
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