The erythrocyte-perfused "working heart" model: Hemodynamic and metabolic performance in comparison to crystalloid perfused hearts

A brief period of ischemia was used to evaluate an erythrocyte-enriched Kre bs-Henseleit (KH) buffer (n=8) compared to KH only (n=8) in an isolated wor king rabbit heart. Experimental protocol was as follows: preischemic baseli ne, 5 min of global ischemia followed by 45 min of reperfusion. Preischemic heart rate was identical, coronary flow was significantly lower (2.7 versu s 5.6 mL/min/g wet wt, p<0.01), the other hemodynamic and biochemical value s were significantly higher in erythrocyte perfused hearts: aortic flow 23. 5 versus 12.0, p<0.01; cardiac output 26.2 versus 17.6, p<0.01; all in mL/m in/g wet wt, dp/dt max 1286 versus 997 mmHg/s, p<0.01; myocardial oxygen co nsumption 3.5 versus 2.3 mu mol/min/g wet wt, p<0.05. During early reperfus ion, in the erythrocyte-perfused hearts, coronary flow further increased (p <0.003), the other hemodynamic parameters returned to baseline values in bo th groups. High-energy phosphates showed significantly higher values (ATP 2 .0+/-0.1 versus 1.3+/-0.1, p<0.05; CrP 2.0+/-0.2 versus 1.6+/-0.1, p<0.05 a ll in mu mol/g wet wt), water content was significantly lower (81% versus 7 4%, p<0.05) in erythrocyte-perfused hearts. It can be concluded that the er ythrocytc-perfused working heart model provides excellent oxygenation, lead ing to superior hemodynamic and metabolic performance. Additionally, in the erythrocyte-perfused hearts preservation of coronary flow reserve underlin es the physiological competency of this preparation. (C) 1999 Elsevier Scie nce Inc.