Page 126 - Computational Modeling in Biomedical Engineering and Medical Physics

Electrical activity of the heart 115

Figure 4.16 The electric field diffusion in the thorax given by the FitzHugh Nagumo model at
three moments: 450 ms (left), 475 ms (middle), and 500 ms (right).

Figure 4.17 The AP for Landau Ginzburg model at three moments: 50 ms (left), 100 ms (middle),
and 150 ms (right).

This behavior is related to the presence of arrhythmias, fibrillations or tachycardia,
which elicits the Landau Ginzburg model a good candidate for noninvasive, reliable
and cost-efficient optimization studies in the cardiac pacing or defibrillation procedures.

The electric field diffusion inside the thorax when coupled with the Landau
Ginzburg epicardial AP is presented in Fig. 4.18 (Morega et al., 2011; Dobre and
Morega, 2011), which shows off the spiral waves on the epicardium.
The electric field calculated inside the thorax may be used to assess the ECG signal
as measured regularly, using the Eindhoven triangle (Morega et al., 2011; Dobre and
Morega, 2011).
The difference between the actual ECG leads and those obtained from the numer-
ical simulations is mainly influenced by the simplified geometry, the approximate loca-
tion of the SA node, and other simplifying hypotheses. The contact resistance
between the electrodes and the skin is neglected here. Better agreement with experi-
mental data is expected to occur should these limitations be alleviated.