Heterogeneity of Micro- and Macro-conduction in Atrial Pectinate Muscles studied with Cardiac Near Field Measurements and Computer Simulation

摘要

Macro- as well as micro-conduction of the car-diac impulse propagation in Pectinate muscles from Rabbit hearts is studied by means of experiments and by means of computer simulation. Two simultaneous recordings of the cardiac near field E allow an estimation of global conduction times (macro) as well as the analysis of the microscopic local activation sequence at given sites. A monodomain 2D computer model based on a micrograph of the area of interest allows to simulate the virtual cardiac near field at any given site. Corre-lation of fine distortions and fractionations in extracellular signals then can be correlated to local particularities of micro-structure not visible during an electrophysiological experi-ment. Experimentally we found that the visible macrostructure of the network often is discordant with the signal characteris-tic, a discrepancy only plausible by effects of microstructure. The computer simulation results based on micrographs con-firm this hypothesis.