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

This Article Full Text (PDF) References 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 Similar articles in PubMed Alert me to new issues of the journal Add to Personal Folders Download to citation manager Author home page(s): Michael K. Pasque David W. Deaton Andrew S. Wechsler Permission Requests Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Freedman, B. M. Articles by Wechsler, A. S. Search for Related Content PubMed PubMed Citation Articles by Freedman, B. M. Articles by Wechsler, A. S.

Ann Thorac Surg 1984;37:309-313
© 1984 The Society of Thoracic Surgeons

---

Articles

Effects of Delay in Administration of Potassium Cardioplegia to the Isolated Rat Heart

Departments of Surgery, Duke University Medical Center and Veterans Administration Medical Center, Durham, NC

Accepted for publication July 6, 1983.

^* Address reprint requests to Dr. Wechsler, PO Box 3174, Department of Surgery, Duke University Medical Center, Durham, NC 27710

Ischemic injury to the heart in the period between aortic cross-clamping and administration of cardioplegic solution was evaluated in the normothermic rat heart model. After isolation and control perfusion with oxygenated Krebs-Henseleit bicarbonate buffer, the hearts were given lactated Ringer's cardioplegic solution (30 mEq of K⁺ per liter) for 2 minutes at three different intervals following aortic clamping: no delay, 2-minute delay, and 5-minute delay. Thereafter, the hearts were left unper-fused and the time to initiation of ischemic contracture was recorded. Adenosine triphosphate (ATP) and creatine phosphate levels were measured in all groups prior to and at the conclusion of cardioplegia administration.

A 2-minute delay in the administration of cardioplegic solution resulted in significantly lower (p < 0.001) ATP levels that were restored after 2 minutes of cardioplegia administration. Contracture times were not significantly altered. A 5-minute delay resulted in significantly shorter (p < 0.001) contracture times and significantly lower (p < 0.001) ATP levels that were not restored to preischemic levels by 2 minutes of cardioplegia administration.

The fate of the myocardium may be insensitive to events that occur during the earliest moments of ischemia provided that rapid administration of oxygenated potassium cardioplegia follows the ischemic period and restores preischemic high-energy phosphate stores. However, there is a critical ischemic time during the initial interval before cardioplegia that is associated with an impaired ability of the myocardium to tolerate subsequent ischemia.

This article has been cited by other articles:

				M. Dewar, M. D. Rosengarten, R. Samson, C. Wittnich, P. E. Blundell, and R. C.- J. Chiu Is High Potassium Solution Necessary for Reinfusions in "Multidose" Cold Cardioplegia? A Randomized Prospective Study Using Computerized Holter System Ann. Thorac. Surg., April 1, 1987; 43(4): 409 - 415. [Abstract] [PDF]

				F. Oguma, S. Imai, and S. Eguchi Role Played by Oxygen in Myocardial Protection with Crystalloid Cardioplegic Solution Ann. Thorac. Surg., August 1, 1986; 42(2): 172 - 179. [Abstract] [PDF]

				J. M. Levett, J. H. Ip, M. H. Kadowaki, C. A. Stennis, and R. B. Karp Preservation of Myocardial High-Energy Phosphates with Vagal Stimulation and Hypothermic Cardioplegia Ann. Thorac. Surg., February 1, 1986; 41(2): 150 - 154. [Abstract] [PDF]