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

This Article Full Text (PDF) 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 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 Search for Related Content

Ann Thorac Surg 1998;65:1564-1565
© 1998 The Society of Thoracic Surgeons

---

Original articles: cardiovascular

Discussion

	Discussion

Top Discussion

 
DR W. RANDOLPH CHITWOOD, JR (Greenville, NC): I very much enjoyed your presentation. My only concern is that in 30% of your cold cardioplegia cohort you used inotropic support. So uniformly, you have shown that tepid cardioplegia is better than your cold cardioplegia comparative data. The question is, to what do you attribute the large use of inotropes in the cold group, because most of these patients had normal ventricles?

DR FIORE: Cold blood cardioplegia has been the universal standard method of myocardial protection. However, it is now known that cold blood cardioplegia is associated with a depression in the enzymatic systems responsible for high-energy phosphate production, elevated levels of coronary vascular resistance, and an increase in cellular damage as evidenced by elevated levels of creatine kinase-MB fraction. These observations can be magnified in patients with prolonged cross-clamp times, even if the preoperative ventricular function is normal. It is not surprising that in this study patients receiving cold blood cardioplegia required inotropic support for the first several hours after separation from the extracorporeal circuit. This observation further strengthens our conviction that tepid blood cardioplegia is a superior form of myocardial protection.

DR FRANCIS ROBICSEK (Charlotte, NC): We learned a long time ago that it is difficult to pass cold blood through the coronary circulation. As a matter of fact, deep hypothermic coronary perfusion with undiluted blood, which is not only very viscous but slow to release its oxygen content, may have disastrous consequences. Because of its very high viscosity, giving cardioplegia using 4°C undiluted blood is contraindicated.

I also would like to ask you, did you monitor perfusion pressure in the coronary arteries, and did you measure the amount of cold blood cardioplegia going through? I suspect there is much less volume going through with a much higher resistance and pressure than in normothermic blood.

DR FIORE: We did monitor the pressure in the aorta, which was approximately 70 mm Hg in both groups. The rate of infusion of cardioplegia was approximately 200 mL/min, which also was similar in both groups.

DR ROBICSEK: I believe that using the same perfusion pressure it is impossible to have the same resistance with undiluted blood of 4°C versus 30°C. So the postulate that you have the same blood flow under different temperature extremes at the same pressure sounds to me extremely unlikely.

DR FIORE: Although we did not measure the actual resistance to flow in the coronary arteries, I suspect you are correct, Dr Robicsek; the resistance is higher with 4°C blood than with 30°C blood.

This article has been cited by other articles:

				K. Lietz, R. John, D. M. Mancini, and N. M. Edwards Outcomes in cardiac transplant recipients using allografts from older donors versus mortality on the transplant waiting list: Implications for donor selection criteria J. Am. Coll. Cardiol., May 5, 2004; 43(9): 1553 - 1561. [Abstract] [Full Text] [PDF]

				H. J. Eisen Adverse outcomes from the use of older donor hearts in cardiac transplant recipients: The pros and cons of expanded donor criteria J. Am. Coll. Cardiol., May 5, 2004; 43(9): 1562 - 1564. [Full Text] [PDF]

This Article Full Text (PDF) 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 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 Search for Related Content