Technics of myocardial protection used in cardiac surgery have been dramatically improved with the use of cardioplegic solutions. These solutions (particularly blood cardioplegic solutions) are routinely administered during open heart surgery. When unclamping the aorta, reperfusion of the ischemic heart with oxygenated blood induces reperfusion injury. Consequently, solutions capable of reducing cellular damage due to reperfusion have been designed. The effectiveness of a reperfusion solution was assessed by a randomized double-blind study including 14 patients with coronary disease. Five biochemical and physiological parameters were measured: coronary resistance, oxygen uptake, total adenine nucleotides, malonaldehyde and lactate. The solution attenuated the reperfusion phenomenon: coronary resistance remained stable, oxygen uptake was increased at the beginning of reperfusion, the pool of nucleotides was preserved and lactate production was reduced. A new study on a larger number of patients is mandatory to establish the place of this reperfusion solution in myocardial protection, particularly in the case of prolonged ischemic time.