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      Untersuchungen über die Hämodynamik des Karotiskreislaufes mit Hilfe von Impedanzmessungen

      ,

      Journal of Vascular Research

      S. Karger AG

      Carotis, Impedance, Pressure-flow relation, Work of vascular muscle, Vasoactive influences

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          Abstract

          The main purpose of the present work was to study the influence of muscular activity on the dynamic behavior of the carotid artery. To this purpose we determined the input impedance of the vessel as a function of frequency. On the other hand, we calculated such impedances theoretically for an elastic tube model closed at the peripheral end, using different parameters such as speed of propagation, damping constant and length. Even a mere qualitative comparison of the experimentally obtained with the calculated impedance-curves yields the following interesting results: if we cancel the muscular activity by injection of papaverine, the carotid clamped at the peripheral end shows a picture which closely ressembles the theoretical one. Also a natural clamped carotid, not influenced by any drug, still shows some general features of the theoretical picture. On the other hand, a striking difference can be observed under the influence of the pressure reducing polypeptide firstly obtained by Laszt [6]. In this case, phase shifts between pressure and flow are largely enhanced beyond the theoretically calculated limits from –90° to +90°. These large phase-shifts can only be accounted for by a negative damping constant β. This, in turn, means that we must introduce in the theory some kind of an amplifying element due to muscular activity. A further interesting result can be obtained if we record pressure and flow shortly after the removal of the clamp. In this case, the impedance-curves show the behavior of a tube with an open end not encountered normally in the arterial circulation. This might be attributed to reactive hyperemia of the peripheral vessels.

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          Author and article information

          Journal
          JVR
          J Vasc Res
          10.1159/issn.1018-1172
          Journal of Vascular Research
          S. Karger AG
          1018-1172
          1423-0135
          1971
          1971
          18 September 2008
          : 8
          : 1
          : 17-30
          Affiliations
          Forschungsinstitut für Kardioangiologie, Freiburg
          Article
          157857 Angiologica 1971;8:17–30
          10.1159/000157857
          © 1971 S. Karger AG, Basel

          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.

          Page count
          Pages: 14
          Categories
          Paper

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