A Mathematical Model of The Atrioventricular Node during Atrial Fibrillation

Abstract:
The atrioventricular (AV) node plays a crucial role during

atrial fibrillation (AF). The aim of this study is to

present an AV node model which can be fitted to short-term

ECG recordings in order to infer certain AV node characteristics.

The proposed model is characterized by: i) the

arrival rate of atrial impulses; ii) two different refractory

periods, corresponding to dual AV nodal paths; iii) the

probability of an atrial impulse choosing either of these

pathways; iv) a parameter modeling prolongation of the

refractory period due to different physiological reasons.

The model was tested on atrial fibrillatory ECGs recorded

from 33 patients; the average normalized absolute error

between the normalized RR histogram and the estimated

model probability density function was 0.0023 ± 0.0016,

(20-ms bin size, 0–2 s interval). These preliminary results

are encouraging as AV nodal properties can be noninvasively

assessed by a set of statistical parameters with a

simple electrophysiological interpretation.