HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Alert me to new issues of the journal Add to Personal Folders Download to citation manager Author home page(s): Avetis Aharonyan David S. Winlaw Permission Requests Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Egan, J. R. Articles by Winlaw, D. S. Search for Related Content PubMed Articles by Egan, J. R. Articles by Winlaw, D. S. Related Collections Cardiac - physiology Cardiac - other Molecular biology Myocardial protection

J Thorac Cardiovasc Surg 2008;136:1265-1273
© 2008 The American Association for Thoracic Surgery

Cardiopulmonary Support and Physiology

Myocardial ischemia is more important than the effects of cardiopulmonary bypass on myocardial water handling and postoperative dysfunction: A pediatric animal model

^a Kids Heart Research, The Children's Hospital at Westmead, Sydney, Australia
^b Discipline of Pediatrics and Child Health, Faculty of Medicine, University of Sydney, Australia

Received for publication January 3, 2008; revisions received March 11, 2008; accepted for publication April 6, 2008.

^_* Address for reprints: David S. Winlaw, MD, FRACS, Paediatric Cardiac Surgeon, Kids Heart Research, Locked Bag 4001, Westmead NSW 2145, Australia. (Email: davidw{at}chw.edu.au).

Objectives: Low cardiac output state is the principal cause of morbidity after surgical intervention for congenital heart disease. Myocardial ischemia–reperfusion injury, apoptosis, capillary leak syndrome, and myocardial edema are associated factors. We established a clinically relevant model to examine relationships between myocardial ischemia, edema, and cardiac dysfunction and to assess the role of the water transport proteins aquaporins.

Methods: Sixteen lambs were studied. Seven were control animals not undergoing cardiopulmonary bypass, and 9 underwent bypass. Six had 90 minutes of aortic crossclamping with blood cardioplegia and moderate hypothermia. The remaining 3 underwent cardiopulmonary bypass without aortic crossclamping. Hemodynamic and biochemical data were recorded, and myocardial edema, apoptotic markers, and aquaporin expression were determined after death.

Results: The group undergoing cardiopulmonary bypass with aortic crossclamping had a low cardiac output state, with early postoperative tachycardia, hypotension, increased serum lactate levels, and impaired tissue oxygen delivery (P < .05) compared with the group undergoing cardiopulmonary bypass without aortic crossclamping. The lambs undergoing cardiopulmonary bypass with aortic crossclamping had increased myocardial water (P < .05) compared with those not undergoing cardiopulmonary bypass and a 2-fold increase in aquaporin 1 mRNA expression (P < .05) compared with those not undergoing cardiopulmonary bypass and those undergoing cardiopulmonary bypass without aortic crossclamping.

Conclusions: A temporal association between hemodynamic dysfunction, myocardial edema, and increased aquaporin 1 expression was demonstrated. Cardiopulmonary bypass without ischemia was associated with minimal edema, negligible myocardial dysfunction, and static aquaporin expression. Ischemic reperfusion injury is the main cause of myocardial edema and myocardial dysfunction, but a causal relationship between edema and dysfunction remains to be proved.

This article has been cited by other articles:

				T. L. Butler, J. R. Egan, F. G. Graf, C. G. Au, A. C. McMahon, K. N. North, and D. S. Winlaw Dysfunction induced by ischemia versus edema: Does edema matter? J. Thorac. Cardiovasc. Surg., July 1, 2009; 138(1): 141 - 147. [Abstract] [Full Text] [PDF]