Panel A: Using the LAO projection, a horizontal line at the level of the lowest part of the pacing lead was drawn. Then 2 lines with angles of 25° to the perpendicular line delineated the anterior wall in the LAO projection.
Panel B: Parallel lines on the upper and on the lower heart silhouette were drawn in the RAO projection. Then a third line parallel to the other two was drawn through the lead tip in the para-hisian region. which divided the right ventricular septum into the RVIT (on or below the line) and the RVOT (above the line).
Figure 3: Schematic representation of the calculated parameters from the UHF-ECG maps.