Retrograde Coronary Perfusion: Effects on Iatrogenic Edema and Diastolic Properties

Abstract

Background. The relative merits of antegrade infusion and retrograde infusion of cardioplegic solution in terms of heart weight, myocardial water content, and ventricular diastolic properties are undefined. Accordingly, we compared antegrade and retrograde flow of hemodiluted blood in isolated, hypothermic porcine hearts. Methods. After cardiectomy, 1 L of cold heparinized blood diluted with lactated Ringer’s solution to concentrations ranging from 100% lactated Ringer’s to 50% lactated Ringer’s and 50% blood was perfused in an antegrade (n = 6) or retrograde (n = 6) fashion at mean pressures of 62 ± 2 mm Hg (± standard error of the mean) and 49 ± 2 mm Hg, respectively. Heart weight, myocardial water content, and left ventricular pressure–volume relationships were obtained before and after perfusion. Results. In the comparison of measurements before and after perfusion, changes in heart weight (36 ± 4 g versus 5 ± 2 g; p < 0.05), myocardial water content (6.9% ± 1.0% versus 2.5% ± 0.4%; p < 0.01), and ventricular filling measured by normalized left ventricular volume at 10, 15, and 20 mm Hg were greater in the antegrade group. Conclusions. In the isolated porcine heart, retrograde flow is distinguished from antegrade flow by less change in heart weight and myocardial water content and no diastolic dysfunction.