Effect of abrupt preload reduction on left atrial and ventricular pressures in a multi-scale mathematical model of the cardiovascular system

(1)

Results

Maximal measured (-‐ -‐) and simulated (–) pressures during preload reduc7on Measured and simulated pressures during one cardiac cycle

Simulated le: atrial pressure-‐ volume loops before (-‐ -‐) and a:er (–) preload reduc7on 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0 10 20 30 40 50 60 70 80 90 Time (s) Pressure (mmHg) 7.5 8 8.5 9 9.5 10 10.5 11 8.5 9 9.5 10 10.5 11 11.5 12 12.5 13 13.5 LA Volume (ml) LA Pressure (mmHg) Le( atrium Aorta Le( ventricle 0 10 20 30 40 50 0 10 20 30 40 50 60 70 80 90 100 Time (s) Pressure (mmHg) Le( ventricle Computer

model of one atrial and one ventricular sarcomere [1].

Simple geometrical model of the le: atrium and ventricle

Computer model of the cardiovascular system

Adjustment of the model parameters to pig experimental data

Methods

PV

LA

LV

Ao

VC

RV

PA

Thin ﬁlament Thick ﬁlament Parallel element Z line e R P, V

Eﬀect of abrupt preload

reduc7on on le: atrial and

ventricular pressures in a

mul7-‐scale mathema7cal

model of the cardiovascular system

A. Pironet1_{,
PC.
Dauby}1_{,
S.
Kosta}1_{,
S.
Paeme}1_,

JG. Chase2_{,
P.
Kolh}1_{,
T.
Desaive}1

1. University of Liège (ULg), GIGA-‐Cardiovascular Sciences, Liège, Belgium

2. University of Canterbury, Department of Biomedical Engineering, Christchurch, New Zealand

Conclusions

This model correctly accounts for LA behavior and responds to preload reduc7on experiments as physiologically expected.

It thus represents a valid subs7tute to the 7me-‐varying elastance method.

[1] Pironet, A., Dauby, P. C., Paeme, S., Kosta, S., Chase, J. G., & Desaive, T. (2013). Simula7on of le: atrial func7on using a mul7-‐scale model of the

cardiovascular system. PLoS ONE, 8(6).

Contact: A.Pironet@ulg.ac.be

The authors declare no compe7ng interest. Le: atrial behavior is diﬃcult

to reproduce in silico.

The 7me-‐ varying elastance theory is widely applied to the le: ventricle.

Purpose

LV Volume LV Pr essur e ESPVR          (V(t), P(t)) Time LV Elastanc e    E(t) = P(t) _V(t)

It is not sure if le: atrial (LA) elastance is load-‐

independent, which prevents its applica7on. LA Volume L A Pr es su re Time LA El as ta nc e

?

      0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 0 10 20 30 40 50 60 70 80 90 0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 0 10 20 30 40 50 60 70 80 90 0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 0 10 20 30 40 50 60 70 80 90 0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 0 10 20 30 40 50 60 70 80 90 Le( ventricle Aorta Le( atrium Preload reducNon