Objective: The aim of this study was to investigate the potentially deleterious effect of in vivo high-fructose feeding of rats on ex vivo hemodynamic recovery and infarct size of isolated rat hearts subjected to low-flow ischemia and reperfusion. Methods: After feeding Sprague-Dawley male rats with a high-fructose (n=9), high-glucose (n=9) or a standard diet (n=9) for four weeks, the hearts were extirpated and perfused ex vivo with a Krebs-Henseleit solution for 15 min; thereafter the hearts were subjected to low flow (0.3 ml/min) ischemia during 30 min followed by 60 min reperfusion. Left ventricular developed pressure (LVDP), first derivative of pressure development during the contraction and relaxation phase and heart rate were recorded prior to ischemia and after reperfusion. Infarct area was measured at the end of the reperfusion period. Results: In isolated hearts, subjected to ex vivo low-flow ischemia followed by 60 min reperfusion, the relative myocardial infarct size did not differ between the three groups. Post-ischemic cardiac contractile recovery appeared to be complete in both the high-fructose and high-glucose group at 60 min reperfusion. In contrast, in the control group LVDP and left ventricular relaxation rate were still depressed at the end of 60 minutes of reperfusion. Conclusion: Feeding with a high-fructose diet of rats appears to have a positive effect on the recovery of left ventricular contractile function after low-flow ischemia, in comparison to a standard diet, without a difference in relative myocardial infarct size. Similar results were obtained in the high-glucose fed rats.