Electrical activation of the ventricular myocardium of the crocodile Crocodylus johnstoni: A combined microscopic and electrophysiological study

Christian, E. and Grigg, G. C. (1999) Electrical activation of the ventricular myocardium of the crocodile Crocodylus johnstoni: A combined microscopic and electrophysiological study. Comparative Biochemistry and Physiology Part A: Molecular & Integrative Physiology, 123 1: 17-23. doi:10.1016/S1095-6433(99)00024-0

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Author Christian, E.
Grigg, G. C.
Title Electrical activation of the ventricular myocardium of the crocodile Crocodylus johnstoni: A combined microscopic and electrophysiological study
Formatted title
Electrical activation of the ventricular myocardium of the crocodile Crocodylus johnstoni: A combined microscopic and electrophysiological study
Journal name Comparative Biochemistry and Physiology Part A: Molecular & Integrative Physiology   Check publisher's open access policy
ISSN 1095-6433
1531-4332
Publication date 1999-05-01
Sub-type Article (original research)
DOI 10.1016/S1095-6433(99)00024-0
Open Access Status File (Author Post-print)
Volume 123
Issue 1
Start page 17
End page 23
Total pages 7
Place of publication Oxford, U.K.
Publisher Pergamon Press/Elsevier
Language eng
Subject 270603 Animal Physiology - Systems
Abstract We mapped the sequence of ventricular depolarization in the crocodile Crocodylus johnstoni. We also attempted to find specialized conduction tissue within the ventricular myocardium. Electrical recordings with miniature multi-point electrodes revealed two strands of rapidly conducting tissue (channels) within the interventricular septum, suggestive of conductive tissue pathways. From these septal channels, wavefronts of excitation swept around each ventricle. Electrical recordings did not indicate that there was conductive tissue in the wall of either ventricle. Similarly, microscopic studies of the septal channels provided no indication of specialized conductive tissue. We suggest that the channels of early septal depolarization provide the crocodile heart with a high speed depolarization pathway functionally analogous to a rudimentary conductive system.
Keyword Activation
Crocodile
Depolarization
Electrical
Heart
Myocardial
Septum
Ventricle
References [1] Burggren WW. Form and function in reptilian circulations. Am Zool 1987;27:5-19. [2] Cranefield PF. The atrioventricular node and the ventricular conducting system in the non- mammalian vertebrate heart. Ann New York Acad Sci 1965;127:145-50. [3] Durrer D, van der Tweel LH. Excitation of the left ventricular wall of the dog and goat. Ann New York Acad Sci 1957;65:779-803. [4] Durrer D, van Dam RT. Freud GE, Janse MJ, Meijler FL. Arzbaecher RC. Total excitation of the isolated human heart. Circulation 1970;16:894-908. [5] Grigg GC. Central cardiovascular anatomy and function in crocodilia. In: Wood S, Weber R, editors. Strategies of physiological adaptation. Proceedings of the Kjell Memorial. Copenhagen: Munksgard, 1991. [6] Harris AS. The spread of excitation in the turtle, dog, cat, and monkey ventricles. Am J Physiol 1941:134:319-22. [7] Kaplan HM. Schwartz C. Electrocardiography in turtles. Life Sci 1963;9:637-45. [8] Koplra EC. The ultrastructure of alligator conductive tissue: an electron microscopic study of the sino-atrial node. Acta Physiol Hung 1987;69(1):27-84. [9] Mullen RK. Comparative electrocardiology of the squamata. Physiol Zool 1967:40:114-216. [10] Robb JS. Specialized (conducting) tissue in the turtle heart. Am J Physiol 1953;172:7-13. [11] Scher ,AM. Young AC. Ventricular depolarization and the genesis of QRS. Ann New York Acad Sci 1957;65:768-78. [12] Scher AM, Roberts DE, Herch LT. Influence of cardiac fiber orientation on wavefront voltage. conduction velocity, and tissue resistivity in the dog. Circ Res 1979:44:701-12 [13] Shmakov KN. Roshchevskii MP. Intramural chronotopography of cardiac ventricular depolarization in reptiles. Zh Evol Biokhim Fizol 1982:18(3):164-9. [14] Spach MS, Barr RC. Ventricular intramural and epicardial potential distributions during ventricular activation and repolarization in the intact dog. Circ Res 1975:37:243-9. [I5] Valentinuzzi ME, Hoff HE. Geddes LA. Observations on the electrical activity of the snake heart. J Electrocardiol 1969:2:39~0. [16] Valentinuzzi ME. Hoff ad HE, Geddes L,1. Electrocardiogram of the snake: effect of the location of the electrodes and cardiac vectors. J Electrocardiol 1969:2:245-53. [17] White FN. Functional anatomy of the heart of reptiles. 4m Zool 1968:8:211-9.
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Q-Index Status Provisional Code
Institutional Status UQ
Additional Notes Originally published as E. Christian and G. C. Grigg (1999) Electrical activation of the ventricular myocardium of the crocodile Crocodylus johnstoni: a combined microscopic and electrophysiological study, Comparative Biochemistry and Physiology - Part A: Molecular & Integrative Physiology, 123 (1): 17-23. Copyright 1999 Elsevier Science. All rights reserved.

Document type: Journal Article
Sub-type: Article (original research)
Collection: School of Biological Sciences Publications
 
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Created: Mon, 08 Aug 2005, 10:00:00 EST by Gordon Grigg on behalf of School of Biological Sciences