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

This Article Alert me when this article is cited Alert me if a correction is posted 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 Permission Requests Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Hiratzka, L. F. Articles by Marcus, M. L. Search for Related Content PubMed PubMed Citation Articles by Hiratzka, L. F. Articles by Marcus, M. L.

The Annals of Thoracic Surgery, Vol 45, 474-481, Copyright © 1988 by The Society of Thoracic Surgeons

ARTICLES

The effects of cardiopulmonary bypass and cold cardioplegia on coronary flow velocity and the reactive hyperemic response in patients and dogs

LF Hiratzka, CL Eastham, JG Carter, JR Moyers, DR Elliott, DB Doty, CB Wright and ML Marcus
Department of Surgery, University of Iowa Hospitals and Clinics, Iowa City.

In normal coronary arteries, reactive hyperemic responses to a 20- second occlusion, an index of coronary reserve, usually demonstrate a peak-to-resting flow velocity ratio of 4:1 or more. Most intraoperative studies that have assessed reactive hyperemic responses in bypassed vessels have reported peak-to-resting flow velocity ratios of 2:1 or less following a 20-second occlusion. These decreased reactive hyperemic responses could be due to coronary vasodilatation after cardiopulmonary bypass or to an inadequate physiological result of the surgical procedure. In 14 patients with angiographically normal coronary arteries, the peak-to-resting flow velocity ratio following a 20-second coronary occlusion decreased significantly (p less than 0.05) from 4.4 +/- 0.2 (mean +/- standard error) before bypass to 3.0 +/- 0.3 after bypass. In a similar dog model, the peak-to-resting flow velocity ratio decreased by 36 to 52% during the first hour following one hour of cardiopulmonary bypass and cardioplegia. During the same period, left ventricular perfusion increased 21 to 30%, mean arterial pressure and coronary vascular resistance decreased, and myocardial oxygen consumption was unchanged. In a second group of dogs studied for the effects of duration (200 to 240 minutes) of anesthesia and thoracotomy alone, peak-to-resting flow velocity ratio was significantly lower. These clinical and experimental studies suggest that major coronary vasodilatation occurs early following cardiopulmonary bypass and cold cardioplegia, and may contribute to the blunted coronary reactive hyperemic responses reported during this time. Consequently, an intraoperative peak-to-resting flow velocity ratio of 3:1 for bypassed coronary arteries may represent an excellent physiological result.

This article has been cited by other articles:

				X. Y. Jin, D. G. Gibson, and J. R. Pepper The effects of cardioplegia on coronary pressure-flow velocity relationships during aortic valve replacement Eur. J. Cardiothorac. Surg., September 1, 1999; 16(3): 324 - 330. [Abstract] [Full Text] [PDF]

				F. W. Sellke, E. M. Boyle Jr, and E. D. Verrier Endothelial Cell Injury in Cardiovascular Surgery: The Pathophysiology of Vasomotor Dysfunction Ann. Thorac. Surg., October 1, 1996; 62(4): 1222 - 1228. [Abstract] [Full Text]

				S. Y. Wang, M. Friedman, A. Franklin, and F. W. Sellke Myogenic Reactivity of Coronary Resistance Arteries After Cardiopulmonary Bypass and Hyperkalemic Cardioplegia Circulation, September 15, 1995; 92(6): 1590 - 1596. [Abstract] [Full Text]