Figure 1
From: Sex and race differences in J-Tend, J-Tpeak, and Tpeak-Tend intervals
Schema of the ECG interval measurement. The top green panel shows the representative beatforms of all 12 ECG leads superimposed on the same isoelectric axis. The middle blue panel shows the derived orthogonal XYZ leads. The bottom red panel shows the vector magnitude of the orthogonal XYZ leads. The vertical dashed lines show the positions of QRS onset, QRS offset (J point), T wave peak, and T wave offset. The interval measurements are shown below the bottom panel. Note that while the 3 panels are synchronised along the horizontal time axis, the scales of the vertical axes are different for the panels. Note also in the top panel that the position of the T wave peak is slightly lead dependent.
