抄録
In right bundle branch block (RBBB), there have been many reports studied experimentally and clinically as to the relationship between abnormal ventricular activation and changes in electrocardiographic QRS patterns. However, the number of lead points in conventional electro-and vectorcardiogram is not sufficient to record all the potential changes produced on the body surface in RBBB. To compensate for this limitation, the body surface isopotential map (hereafter abbreviated as map) has recently been introduced. This map is expressed in the form of an equipotential contour map based on the data from a large number of unipolar lead electrocardiograms on the body surface. Comparison with the conventional electro-and vectorcardiogram has shown that the map contains much information about local activation in the heart. Therefore, the map will be a more useful method in explaining several cardiac abnormal excitations. In this report, using a simulation of the ventricular propagation process and a method for computational reconstruction of the map which were developed by the author, simulation of the ventricular propagation in RBBB was performed and the map was reconstructed. The correlation between the reconstructed map and the propagation process in the heart model was used to investigate the genesis of a clinical RBBB map. Methods: 1. Simulation of the ventricular propagation process in RBBB As reported previously, the heart model based on the post-mortem human heart was stored in memory of a large digital computer. In order to simulate more precisely the propagation process than that in the previous heart model which was composed of a cluster of 3 mm cubic blocks, the block size was cut to the 1.5 mm cubic one. In this new heart model, simulation of ventricular propagation process in RBBB was performed.