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): John E. Baker Gordon N. Olinger Permission Requests Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Baker, J. E. Articles by Olinger, G. N. Search for Related Content PubMed PubMed Citation Articles by Baker, J. E. Articles by Olinger, G. N.

Ann Thorac Surg 1993;55:747-755
© 1993 The Society of Thoracic Surgeons

---

Articles

Age and protection of the ischemic myocardium: Is alkaline cardioplegia appropriate?

Department of Cardiothoracic Surgery, Medical College of Wisconsin, Milwaukee, Wisconsin, USA

Accepted for publication July 14, 1992.

^_* Address reprint requests to Dr Baker, Department of Cardiothoracic Surgery, Medical College of Wisconsin, 8701 Watertown Plank Rd, Milwaukee, WI 53226.

Hypothermic alkaline pharmacologic cardioplegia used in pediatric cardiac surgery may be less than satisfactory despite its benefits in adults. We determined whether the pH (7.8) of standard St. Thomas' II cardioplegic solution contributes to inadequate protection of the ischemic immature heart and whether the effect is age-related. Modified hypothermic St. Thomas' II solution (pH range, 4.8 to 8.8) was compared with hypothermic bicarbonate buffer alone (pH 7.25) in protecting the ischemic immature (7 to 10 days old) and mature (12 months old) rabbit heart. Isolated hearts (n = 6 per group) were perfused with bicarbonate buffer, and aortic flow was measured before hypothermic (14 °C) ischemia (immature hearts: 4 hours; mature hearts: 3 hours). Hearts were reperfused, and enzyme leakage and recovery of function were measured. In the immature heart, a bellshaped dose-response profile was observed for pH and recovery of aortic flow but not for postischemic creatine kinase leakage. Optimal recovery of aortic flow (98% ± 3%) occurred at pH 6.8, which was greater than protection with hypothermia alone (82% ± 4%; p < 0.05) and standard St. Thomas' II solution (72% ± 2%; p < 0.05). In the mature heart, a bell-shaped dose-response curve existed for recovery of aortic flow and a U-shaped curve existed for creatine kinase leakage. Again, optimal recovery of aortic flow (84% ± 5%), which was superior to that with standard St. Thomas' II solution (60% ± 8%; p < 0.05), and minimal enzyme leakage also occurred at pH 6.8, as did the least enzyme leakage (p < 0.05). The pH of standard St. Thomas' II solution is suboptimal to protect the ischemic immature and mature myocardium, and protection is improved by mild acidification.

This article has been cited by other articles:

				T. Doenst, C. Schlensak, and F. Beyersdorf Cardioplegia in pediatric cardiac surgery: do we believe in magic? Ann. Thorac. Surg., May 1, 2003; 75(5): 1668 - 1677. [Abstract] [Full Text] [PDF]

				R. Bessho and D. J. Chambers Myocardial protection with oxygenated esmolol cardioplegia during prolonged normothermic ischemia in the rat J. Thorac. Cardiovasc. Surg., August 1, 2002; 124(2): 340 - 351. [Abstract] [Full Text] [PDF]

				M. Tonkovic-Capin, G. J. Gross, Z. J. Bosnjak, J. S. Tweddell, C. M. Fitzpatrick, and J. E. Baker Delayed cardioprotection by isoflurane: role of KATP channels Am J Physiol Heart Circ Physiol, July 1, 2002; 283(1): H61 - H68. [Abstract] [Full Text] [PDF]

				H. Imura, M. Caputo, A. Parry, A. Pawade, G. D. Angelini, and M.-S. Suleiman Age-Dependent and Hypoxia-Related Differences in Myocardial Protection During Pediatric Open Heart Surgery Circulation, March 20, 2001; 103(11): 1551 - 1556. [Abstract] [Full Text] [PDF]

				M. A. Portman, A. L. Panos, Y. Xiao, D. L. Anderson, G. M. Alfieris, X.-H. Ning, and F. M. Lupinetti INFLUENCE OF THE pH of CARDIOPLEGIC SOLUTIONS ON CELLULAR ENERGY METABOLISM AND HYDROGEN ION FLUX DURING NEONATAL HYPOTHERMIC CIRCULATORY ARREST AND REPERFUSION: A DYNAMIC 31P NUCLEAR MAGNETIC RESONANCE STUDY IN A PIG MODEL J. Thorac. Cardiovasc. Surg., October 1, 1997; 114(4): 601 - 608. [Abstract] [Full Text]

				I. B. Krukenkamp and S. Levitsky Myocardial Protection: Modern Studies Ann. Thorac. Surg., May 1, 1996; 61(5): 1581 - 1582. [Full Text]

				E. J. Baker and J. E. Baker Calcium and cardioplegic protection of the ischemic immature heart: Impact of hypoxemia from birth Ann. Thorac. Surg., October 1, 1994; 58(4): 1123 - 1130. [Abstract] [PDF]

				J. C. Stringham, K. L. Paulsen, J. H. Southard, R. M. Mentzer Jr, and F. O. Belzer Forty-hour preservation of the rabbit heart: Optimal osmolarity, [Mg2+], and pH of a modified UW solution Ann. Thorac. Surg., July 1, 1994; 58(1): 7 - 13. [Abstract] [PDF]