Measurements of coronary microvascular parameters in situ are difficult because of the thickness of the heart muscle and cardiac contraction. Both of these problems hamper the visualization of the coronary microcirculation. We have refined methodological approaches that enable the study of the coronary microcirculation in situ. In the first approach, microvessels can be visualized in the beating heart using a preparation that compensates for cardiac motion by creating an illusion that the heart is motionless. This is accomplished by flashing a stroboscopic light source once per heart cycle at the same point in each cycle and synchronizing a ventilator with the cardiac cycle. Images of microvessels can be obtained using standard intravital video-microscopic techniques. To visualize the intramural and subendocardial microcirculation, studies are completed in isolated hearts. In this preparation, measurements of microvascular diameters and pressures can be performed in both the subepicardial and subendocardial microcirculations. This latter approach allows insight into transmural differences of coronary microvascular regulation.
Copyright: All rights reserved. No part of this publication may be translated into other languages, reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying, recording, microcopying, or by any information storage and retrieval system, without permission in writing from the publisher. Drug Dosage: The authors and the publisher have exerted every effort to ensure that drug selection and dosage set forth in this text are in accord with current recommendations and practice at the time of publication. However, in view of ongoing research, changes in government regulations, and the constant flow of information relating to drug therapy and drug reactions, the reader is urged to check the package insert for each drug for any changes in indications and dosage and for added warnings and precautions. This is particularly important when the recommended agent is a new and/or infrequently employed drug. Disclaimer: The statements, opinions and data contained in this publication are solely those of the individual authors and contributors and not of the publishers and the editor(s). The appearance of advertisements or/and product references in the publication is not a warranty, endorsement, or approval of the products or services advertised or of their effectiveness, quality or safety. The publisher and the editor(s) disclaim responsibility for any injury to persons or property resulting from any ideas, methods, instructions or products referred to in the content or advertisements.