Myocardial Protection of the Homograft

Abstract

Because of profound heart failure immediately after orthotopic transplanta tion, experiments were designed to evaluate the effect of induced ventricular fibrillation and initial cold coronary perfusion followed by the use of a cooling bag on the protection of the homograft during implantation and the subsequent improvement of its performance. Group I: 7 dog hearts immediately immersed in cold saline after resection were transplanted orthotopically. Group II: in 5 donors, after induced ventricular fibrillation and initial hypothermic coronary perfusion, the graft was isolated in a cooling bag until completion of surgical anastomosis. Both groups were prepared for hemodynamic studies which were carried out in the resting state 3, 24 and 48 hours postoperatively. In group I, myocardial temperature decreased to 12.5 within 13 minutes; afterward it rose rapidly to 25°C. In group II induced hypothermia was more rapid and more profound (11°C in 10 min); it was then maintained between 12° and 16.5°C with the cooling bag. Three hours post-op cardiac performance in group II was much higher than in group I as demonstrated by increases in CI (+69%), SVI (+98%), MSERI (+57%), PVI (+54%), M_xAccI (+38%), SPI (+79%), SWI (+ 130%). Twenty-four hours after surgery, cardiac function had improved in both groups but remained superior in group II (CI + 44%), (SVI + 39%), (MSERI + 31%), (PVI + 27%), (SPI + 27%), (SWI + 39%). Forty-eight hours postoperatively, some of the data remained slightly superior in group II (CI + 20%), (SVI + 26%), (MSERI + 23%).