Coronary Blood Flow: Mechanics, Distribution, and Control

408 Pages·1991·16.416 MB·English

by  Jos A. E. Spaan (auth.)

CORONARY BLOOD FLOW
Mechanics, Distribution, and Control
Developments in
Cardiovascular Medicine
VOLUME 124
The titles published in this series are listed at the end a/this volume.
CORONARY
BLOODFLOW
Mechanics, Distribution, and Control
by
JOS A. E. SPAAN
Professor of Medical Physics,
Cardiovasclilar Research Institute Amsterdam (CRIA),
Amsterdam, Tlle Netherlands
SPRINGER-SCIENCE+BUSINESS MEDIA, B.V.
Library of Congress Cataloging-in-Publication Data
Spaan. Jos A. E.
Coronary blood flow mechanics. distribution. and control/Jos
A.E. Spaan.
p. cm. -- (Developments in cardiovascular medicine : v. 124)
Includes bibllograph1cal references and indexes.
ISBN 978-94-010-5388-4 ISBN 978-94-011-3148-3 (eBook)
DOI 10.1007/978-94-011-3148-3
1. Coronary circulat1on. I. Title. II. Series.
[DNLM: 1. Blood Flow Velocity. 2. Coronary Circulation. W1
DE997VME v. 124 ! WG 300 S7337cl
OP108.S62 1991
612.1 '7--dc20
DNLM/DLC
for Llbrary of Congress 91-7047
ISBN 978-94-010-5388-4
Printed on acid-ft'ee paper
Ali Rights Reserved
© 1991 Springer Science+Business Media Dordrecht
Origina1ly published by Kluwer Academic Publishers in 1991
Softcover reprint of the hardcover 1s t edition 1991
No part of the material protected by this copyright notice may be reproduced or
utilized in any form or by any means, electronic or mechanical,
including photocopying, recording or by any information storage and
retrieval system, without written permission from the copyright owner.
Layout and typesetting: BOB VAN DER LINDEN
Cover picture: Vessels sprouting from subepicardial capillary network
feeding epicardial fat.
Made by: drs. M.M. Stork at CVRI, San Francisco
With contributions by:
Jenny Dankelman, Maurice J.M.M. Giezeman, Yves Han,
Ed van Bavel, Jan Verburg, Isabelle Vergroesen,
and Peter A, Wieringa
To my lovely daugthers
Tjitske
and
Nienke
With respect to my Teachers in Science
Pieter C. Veenstra
Ferdinand Kreuzer
John D. Laird
Contents
Foreword by JIE Hofflllan XVII
Author's preface XIX
Acknowledgelllents XXIII
1 Basic coronary physiology 1
1.1 Introduction.... ... ......... 1
1.1.1 Heart function and coronary flow . . 1
1.1.2 Control and extravascular resistance 2
1.1.3 Distribution of supply and demand . 3
1.1.4 Mechanics, control and distribution in the coronary circu-
lation .. .... . . . . . . . . . 4
1.2 Coronary flow mechanics. . . . . . . . . . . . . . . . . . 5
1.2.1 Inhibition of coronary arterial flow during systole. . . . . 6
1.2.2 Retrograde coronary arterial flow, venous flow and in-
tramyocardial compliance . . . . 8
1.3 Regulation of coronary flow . . . . . . . . . 12
1.3.1 Steady local control of coronary flow 12
1.3.2 How to define coronary tone? . . 14
1.3.3 Rate of adaptation of the coronary circulation to step
changes in heart rate . . . . . . . 17
1.3.4 Effect of perfusion pressure step .. 19
1.3.5 Reactive hyperemia ......... 20
1.3.6 Mechanisms of coronary flow control 21
1.4 Heterogeneity in myocardial perfusion and oxygen supply 24
1.4.1 Distribution of flow from endocardium to epicardium. 24
1.4.2 Heterogeneity induced by the arterial tree. .. .. 26
1.4.3 Heterogeneity of oxygen supply/demand ratio . . . . 28
1.5 Relation between mechanics, control and distribution of coronary
flow ... . . . . .. .. ... . 28
x Contents
1.6 Summary 30
References . . . 30
2 Structure and function of the coronary arterial tree 37
2.1 Basic anatomy ............ . 38
2.2 Collaterals......................... 40
2.3 Structure of the coronary arterial tree . . . . . . . . . 40
2.3.1 Ratios between diameters of mother and daughter branches 41
2.3.2 Growth of arterial cross-sectional area . . . . . . . . . . . . 43
2.3.3 Length distribution in the arterial tree . . . . . . . . . . . . 44
2.3.4 Arterial density applying symmetrical branching networks. 46
2.4 Data on filling volume of the coronary arterial tree . 49
2.5 Pressure distribution in the coronary arterial tree . . 49
2.6 Symmetrical, dichotomous branching network model 51
2.6.1 Definition of model structure 52
2.6.2 Prediction of volume . . . . . . . . . . . . . . 53
2.6.3 Prediction of pressure . . . . . . . . . . . . . 54
2.7 N onsymmetrical dichotomous branching network analysis 58
2.7.1 Strahler ordering ................. . 58
2.7.2 Fractal models .................. . 60
2.8 Discussion on structure and function of the arterial tree 62
2.9 Summary 63
References . . . . . . . . . . . . . . . . . . . . . . . 64
3 Structure and perfusion of the capillary bed 69
3.1 Structure of capillary bed . . 69
3.2 Capillary density and volume 70
3.3 Mechanical properties . . . . 72
3.4 Red cells in the capillary bed 74
3.4.1 Velocities . . . . . . . 74
3.4.2 Red cell distribution at bifurcations 74
3.4.3 Hematocrit . . . . . . . . . . . . . . 76
3.5 Model of parallel and homogeneous perfused capillary bed 77
3.6 A model for the heterogeneous perfusion of the capillary bed 79
3.7 Capillary recruitment in the heart 82
3.8 Summary 83
References . . . . . . . . . . . . . . . . . 84
4 Structure and function of coronary venous systeIn 87
4.1 Basic anatomy ... . . . . . . . . . . . . . . . 87
4.2 Distribution of coronary venous flow . . . . . . 89
4.3 Flow and pressure waves in the epicardial veins 92
4.4 Waterfall behavior of coronary epicardial veins 95
Contents XI
4.5 Coronary venous compliance 95
4.6 Summary 96
References . . . . . . . . . . . . . . 96
5 Linear system analysis applied to the coronary circulation 99
5.1 Definitions ... . .100
5.1.1 System ........... . .100
5.1.2 Linearity .......... . .101
5.1.3 Time and frequency domains .103
5.1.4 Models ........... . .103
5.1.5 Load line analysis ..... . .104
5.2 Linear intramyocardial pump model .106
5.2.1 Interpretation of the coronary load lines .107
5.2.2 Intramyocardial pump and the right coronary artery .111
5.2.3 Shortcomings of the linear intramyocardial pump model .111
5.3 Load line analysis of collateral flow . . . . . . .111
5.4 Input impedance ...................... . .115
5.4.1 Input impedance during long diastoles ...... . .115
5.4.2 Coronary impulse response in diastole and systole .117
5.4.3 Model interpretation of coronary input impedance .118
5.5 Nonlinear physical elements and linear
system analysis . . . . . . . . . . . . . . . . . . . . . . . .122
5.6 Discussions of the linear models of coronary circulation. .125
5.7 Summary .126
References. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .127
6 Interaction between contraction and coronary flow: Theory 131
6.1 Systolic extravascular resistance model ......... . .132
6.1.1 Basic behavior of extravascular resistance model .134
6.1.2 Discussion of extravascular resistance model. .134
6.2 The waterfall model ................. . .135
6.2.1 Basic model behavior of the waterfall model. .137
6.3 Nonlinear intramyocardial pump model ...... . .140
6.3.1 Pressure dependency of compartmental resistance. .142
6.3.2 Steady state arterial pressure-flow relations during arrest .144
6.3.3 Solutions for the subendocardial model layer of the con-
tracting myocardium . . . . . . . . .146
6.3.4 Compartmental volume variations .147
6.3.5 Flow simulations . . . .149
6.4 Variable elastance model. . . . . . .151
6.4.1 Experimental support ... . 151
6.4.2 Variable elastance concept . .151
XII Contents
6.4.3 A mathematical intramyocardial pump model with time
varying elastance as pump generator . 155
6.5 Discussion. .159
6.6 Summary .160
References . . . . .161
7 Interaction between contraction and coronary flow: Experiment163
7.1 Parallel shift of pressure-flow relations. . . . 164
7.2 Pressure dependency of coronary resistance . 166
7.3 Effect of heart rate on microsphere
distribution . . . . . . . . . . . . . . . . . . . 168
7.4 Contractility and microsphere distribution. . 172
7.5 Intramyocardial compliance . . . . . . . . . . 174
7.6 Pulsations in coronary pressure at constant flow perfusion . 178
7.7 Diastolic pressure-flow lines . 180
7.8 Discussion. . 186
7.9 Summary . 187
References . . . . . 188
8 Arteriolar mechanics and control of flow 193
8.1 Morphology of the arteriolar wall . 194
8.2 Myogenic response . . . . . . . . . . . . 195
8.3 Arteriolar vasomotion . . . . . . . . . . 198
8.4 Strain and stress in the arteriolar wall . 200
8.5 Myogenic responses in relation to autoregulation of flow . 205
8.5.1 Relation between pressure and resistance with and without
myogenic tone .............. . 206
8.5.2 Width of the autoregulatory plateau . . . 206
8.5.3 The optimal strength of myogenic tone. . 208
8.6 Compliance of arterioles . . . . . . . . . . . . . . 210
8.6.1 Effect of tone on static compliance . . . . 210
8.6.2 Quasi-static distensibility of dilated coronary arteries . 212
8.6.3 Frequency dependency of distensibility of active and pas-
sive small coronary arteries . 212
8.7 Discussion................. . 214
8.7.1 Vasodilation............ .214
8.7.2 Arterioles and regulation of flow .215
8.8 Summary . 216
References. . . . . . . . . . . . . . . . . . . . . 217