3.2 Electrophysiology of the Heart

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81

time t / s

U / mV

AV node

Fig. 3.27: Partially synchronised oscillations of the AV node according to Figure 3.23 and Figure 3.24

with stronger coupling of the sinus node to the AV node, where the AV node can no longer follow the

signal of the sinus node due to a too low natural frequency (kSA−AV = 12, kAV−AV = 1, eSA = 12 and

eAV = 9).

time t / s

U / mV

AV node

Fig. 3.28: Non-synchronisable oscillations of the AV node according to Figure 3.23 and Figure 3.24

when the sinus node is too strongly coupled to the AV node, whereby the oscillation of the AV node

stops completely after irregular dropouts, i.e. the point of singularity has been reached (kSA−AV =

12, kAV−AV = 1, eSA = 12 ’eAV = 7).

Purkinje-complex (HP) xHP(t) overlap and have different effects on the body surface.

The ECG signal can therefore be described approximately linearly by an addition of

these signals weighted with the attenuation factors aSA, aAV, and aHP [20]:

xECG(t) = aSAxSA(t) + aAVxAV(t) + aHPxHP(t) .

(3.27)

Since the cardiac excitation travels from the sinus node via the atrial node and then

via the AV node to the main chamber, the coupling of the three oscillators should be