TY - JOUR
T1 - Time-domain representation of ventricular-arterial coupling as a windkessel and wave system
AU - Wang, Jiun Jr
AU - O'Brien, Aoife B.
AU - Shrive, Nigel G.
AU - Parker, Kim H.
AU - Tyberg, John V.
PY - 2003/4/1
Y1 - 2003/4/1
N2 - The differences in shape between central aortic pressure (PAo) and flow waveforms have never been explained satisfactorily in that the assumed explanation (substantial reflected waves during diastole) remains controversial. As an alternative to the widely accepted frequency-domain model of arterial hemodynamics, we propose a functional, time-domain, arterial model that combines a blood conducting system and a reservoir (i.e., Frank's hydraulic integrator, the windkessel). In 15 anesthetized dogs, we measured PAo, flows, and dimensions and calculated windkessel pressure (Pwk) and volume (Vwk). We found that PWk is proportional to thoracic aortic volume and that the volume of the thoracic aorta comprises 45.1 ± 2.0% (mean ± SE) of the total Vwk. When we subtracted Pwk from PAo, we found that the difference (excess pressure) was proportional to aortic flow, thus resolving the differences between PAo and flow waveforms and implying that reflected waves were minimal. We suggest that PAo is the instantaneous summation of a time-varying reservoir pressure (i.e., Pwk) and the effects of (primarily) forward-traveling waves in this animal model.
AB - The differences in shape between central aortic pressure (PAo) and flow waveforms have never been explained satisfactorily in that the assumed explanation (substantial reflected waves during diastole) remains controversial. As an alternative to the widely accepted frequency-domain model of arterial hemodynamics, we propose a functional, time-domain, arterial model that combines a blood conducting system and a reservoir (i.e., Frank's hydraulic integrator, the windkessel). In 15 anesthetized dogs, we measured PAo, flows, and dimensions and calculated windkessel pressure (Pwk) and volume (Vwk). We found that PWk is proportional to thoracic aortic volume and that the volume of the thoracic aorta comprises 45.1 ± 2.0% (mean ± SE) of the total Vwk. When we subtracted Pwk from PAo, we found that the difference (excess pressure) was proportional to aortic flow, thus resolving the differences between PAo and flow waveforms and implying that reflected waves were minimal. We suggest that PAo is the instantaneous summation of a time-varying reservoir pressure (i.e., Pwk) and the effects of (primarily) forward-traveling waves in this animal model.
KW - Aortic flow
KW - Aortic pressure
KW - Compliance
KW - Left ventricular ejection
KW - Waves
UR - http://www.scopus.com/inward/record.url?scp=0037379192&partnerID=8YFLogxK
U2 - 10.1152/ajpheart.00175.2002
DO - 10.1152/ajpheart.00175.2002
M3 - Article
SN - 0363-6135
VL - 284
SP - H1358-H1368
JO - American Journal of Physiology - Heart and Circulatory Physiology
JF - American Journal of Physiology - Heart and Circulatory Physiology
IS - 4 53-4
ER -