caa a22 4500 465783961 CHVBK 20180323112003.0 cr unu---uuuuu 170327e19900301xx s 000 0 eng 10.1007/BF02441769 doi (NATIONALLICENCE)springer-10.1007/BF02441769 System analysis of the dynamic response of the coronary circulation to a sudden change in heart rate [Elektronische Daten] [J. Dankelman, H. Stassen, J. Spaan] In this study the response of driving pressure/flow ratio on an abrupt change in heart rate was analysed. The difference between the response obtained with constant pressure and constant flow perfusion was also studied. The responses show a fast initial reversed phase followed by a slow phase caused by regulation. To test whether the initial phase could be the result of mechanical changes in the coronary circulation, a model for regulation was extended by the addition of four different mechanical models originating from the literature. These extended models were able to explain the fast initial phase. However, the mechanical model consisting of an intramyocardial compliance (C=0·08 ml mm Hg−1 100 g−1) with a variable venous resistance, and the model consisting of a waterfall and a small compliance (C=0·007 ml mm Hg−1 100 g−1) both explained these responses best. The analysis showed that there is no direct relationship between rate of change of vascular tone and rate of change of pressure/flow ratio. However, on the basis of the two extended models, it can be predicted that the half-time for the response of regulation to be complete is about 9s with constant pressure perfusion and 15 s with constant flow perfusion. IFMBE, 1990 Coronary circulation nationallicence Dynamics of regulation nationallicence Heart rate nationallicence Mathematical model nationallicence b : r v(0)v 2(0) nationallicence C : intramyocardial compliance nationallicence d : 2(p b(0)−P v)/(r v(0)v(0)) nationallicence HR : heart rate nationallicence k 1 : m(0)/p im(0) nationallicence k 2 : r a(0)/o(0) nationallicence m(t) : oxygen consumption nationallicence o(t) : supply of oxygen to issue nationallicence o 2( t ) : oxygen concentration in tissue nationallicence O a : arterial oxygen concentration nationallicence p p(t) : arterial perfusion pressure nationallicence p im(t) : intramyocardial pressure nationallicence p b(t) : blood pressure between arteriolar and venous resistance nationallicence p s(t) : pressure proximal to the stenosis nationallicence p tr(t) : p b(t)−p im(t), transmural pressure nationallicence P v : venous pressure nationallicence q a(t) : coronary arterial flow nationallicence q v(t) : coronary venous outflow nationallicence r a(t) : arterial resistance nationallicence r cor(t) : total coronary resistance nationallicence R s : stenosis, high resistance nationallicence r sa(t) : R s+r a(t) nationallicence r sc(t) : R s+r cor(t) nationallicence R v, r v(t) : venous resistance nationallicence t 1 : time constant for mixing in capillaries and tissue nationallicence t 2 : time constant for a change ofr a on a change ino nationallicence v(t) : volume of the capillary vessels nationallicence w(t) : m(t)/q a(t) nationallicence Dankelman J. Laboratory for Measurement & Control, Faculty of Mechanical Enginering & Marine Technology, Delft University of Technology, Mekelweg 2, 2620 CD, Delft, The Netherlands aut Stassen H. Laboratory for Measurement & Control, Faculty of Mechanical Enginering & Marine Technology, Delft University of Technology, Mekelweg 2, 2620 CD, Delft, The Netherlands aut Spaan J. Laboratory for Measurement & Control, Faculty of Mechanical Enginering & Marine Technology, Delft University of Technology, Mekelweg 2, 2620 CD, Delft, The Netherlands aut Medical and Biological Engineering and Computing Kluwer Academic Publishers 28/2(1990-03-01), 139-148 0140-0118 28:2<139 1990 28 11517 https://doi.org/10.1007/BF02441769 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF02441769 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Dankelman J. Laboratory for Measurement & Control, Faculty of Mechanical Enginering & Marine Technology, Delft University of Technology, Mekelweg 2, 2620 CD, Delft, The Netherlands aut NATIONALLICENCE 700 1- Stassen H. Laboratory for Measurement & Control, Faculty of Mechanical Enginering & Marine Technology, Delft University of Technology, Mekelweg 2, 2620 CD, Delft, The Netherlands aut NATIONALLICENCE 700 1- Spaan J. Laboratory for Measurement & Control, Faculty of Mechanical Enginering & Marine Technology, Delft University of Technology, Mekelweg 2, 2620 CD, Delft, The Netherlands aut NATIONALLICENCE 773 0- Medical and Biological Engineering and Computing Kluwer Academic Publishers 28/2(1990-03-01), 139-148 0140-0118 28:2<139 1990 28 11517 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer