Identifying patterns of spatial current dispersion that characterise and separate the Brugada syndrome and complete right-bundle branch block.

The aim of the study was to detect patterns of spatial-current distribution in the late QRS and early ST-segments that distinguish Brugada-syndrome cases from complete right-bundle branch block (CRBBB). Magnetocardiograms (MCGs) were recorded from Brugada-syndrome patients (n = 6), CRBBB patients (n = 4) and the members of a control group (n = 33). The current distributions at six time points from Q-onset were estimated by producing current-arrow maps (CAMs). The angle of the current arrow of maximum amplitude at each time point was calculated. In the Brugada cases, the characteristic ST elevation was seen above the upper right chest, and abnormal currents appeared to be present in the right-ventricular outflow tract (RVOT). The angles of the abnormal arrows were -78 degrees +/- 51 degrees at 100 ms and -50 degrees +/- 61 degrees at 110 ms. In the cases of CRBBB, wide S- and R-waves were recorded above the upper right and lower right chest, respectively. The angles of the abnormal arrows for CRBBB were 152 degrees +/- 19 degrees at 100 ms, 159 degrees +/- 20 degrees at 110 ms, and 157 degrees +/- 19 degrees at 120 ms. The findings suggest that an abnormal current from the RVOT to the upper left chest may be a feature of the Brugada syndrome, and that the direction of this current is completely different from that seen in CRBBB.