[Assessment of the viability of preserved hearts--birefringence test using a polarizing microscope]

The viability of preserved hearts was assessed using the quantitative polarizing microscopic technique or the birefringence test introduced by Braimbridge et al. To clarify the correlation between myocardial degeneration and the change of birefringence, twelve rat hearts under various preserved conditions were examined. To evaluate usefulness of the birefringence test in heart transplantation, thirteen pairs of mongrel dogs were subjected to heterotopic heart transplantation. Among these thirteen, seven were transplanted immediately and another six were transplanted following preservation in cold Collins-M solution for 12 hours. Biopsy specimens were taken at the time of harvest, after preservation, immediately after and 2 hours after transplantation and examined by a polarizing microscope which could measure the change in birefringence following addition of ATP. They were also examined electron-microscopically for degenerative changes. The results of the birefringence test correlated well with the change of the electron microscopic observation and the hemodynamic activities of the transplanted hearts. Thus, it was concluded that the birefringence test was a useful method to evaluate myocardial viability for transplantation within a short time.