A new rejection criteria in the heterotopically placed rat heart by non-invasive measurement of Dp/Dtmax

Abstract Background The heterotopic heart of rats has been a useful model in the evaluation of immunomodulatory protocols. Graft palpation usually determines the day of rejection. We present in this paper an original method of graft monitoring in allograft rejection. Methods Heterotopic cardiac abdominal transplantation was performed in Lewis isografts ( n = 15) and in ACI to Lewis allograft ( n = 15). A balloon connected to a measurement device was inserted in the left ventricle, and calculation of Dp/Dt max was possible by recording the intra-left ventricular pressure. A ten-day follow-up was achieved with a daily comparison of palaption, ECG, and Dp/Dt max . Results In transplanted hearts, Dp/Dt max did not change in isografts but significantly decreased in allograft on posttransplantation Day 5 (PTD 5) vs PTD 0.1 and 3 ( p max values on PTD 5 and 6 were also statistically significant in allograft vs isograft group ( p Conclusion This study shows that daily measurement of Dp/Dt max in heterotopic heart is made possible by our implantable system without interrupting the graft, and gives a more accurate definition of graft rejection than a combination of palpation and ECG. In addition, this method would seem desirable when differences in survival may be expected to be of lesser magnitude.