Improved myocardial preservation by control of the oxidation-reduction potential. 
Simple cold storage remains the current method of preservation of human heart allografts between removal and transplantation, but this technique is not adequate for prolonged periods of preservation.  An alternative to cold storage is machine perfusion of the isolated organ.  Although this technique has yielded promising results in kidney preservation, there is limited experience with the heart.  One factor limiting the effectiveness of perfusion preservation is the toxicity of oxygen free radicals generated during the perfusion.  The generation and reduction of these radicals results in an electron transfer, producing an electrochemical potential known as the redox potential.  This study examines the role of machine perfusion in heart preservation with and without the use of a new electrochemical cell that is able to control the redox potential during the perfusion.  Hearts were preserved for twenty-four hours by either simple cold storage (Group I), or by machine perfusion with redox monitoring (Group II), or redox control (Group III).  Control of the oxidation-reduction potential of the perfusate during machine perfusion of isolated hearts resulted in significantly improved systolic and diastolic function after perfusion compared to hearts that underwent machine perfusion without redox control or simple cold storage.