Figure 1.
Block diagram of the overall beat-to-beat VCG approach.
The solid line of rectangular or square represents the different processes or methods. The rectangles with dashed lines (at the bottom) represent the output parameters (descriptors).
Figure 2.
Point-to-point distance of ECG loops.
The purple coloured loop depicts the mean loop. The long arrow depicts the peak of R or T-wave, respectively. Left: Schematic representation of superimposed ECG loops for several cardiac cycles. Right: The small arrows show the distance from each point of an individual loop representing one cardiac cycle to the mean loop.
Figure 3.
TCRT of the QRS-loop and T-loop.
The ‘total cosine R-to-T’ (TCRT) describes the difference in global wavefront directions of depolarization and repolarization. The angle α is the angle between the main vectors of the QRS and T-loops.
Table 1.
QRS and T-loop descriptors in the control and MI groups.
Figure 4.
Beat-to-beat depolarization and repolarization loops in a control subject and a MI patient.
The QRS (A) and T loops (B) and their combination of a normal subject are shown in red and magenta. The QRS (D) and T-loops (E) and their combination (F) of a MI patient (G) are shown in blue and green.
Figure 5.
Group comparison of ventricular depolarisation and repolarization parameters.
Point-to-point distance variabilityin QRS-loops (A) and T-loops (B), mean loop length of QRS-loops (C) and T-loops (D). Mean (E) and standard deviation (F) of TMD and mean PL (G) show significant differences between normal subjects and MI patients.
Figure 6.
Data are presented as mean and SD (in ascending order from left to right based on their mean value) of TCRT for individual control subjects (A) and MI patients (B).