There is increasing attention being given toward social and ethical implications of xenotransplantation that may begin relatively soon. IN a recent commentary by Loebe and Parker, the authors address many of the social and ethical issues in regard to xenotransplantation, but do so only superficially. This letter to the editor responds to many of the points they raise.

We report a case of spontaneous mechanical papillary muscle rupture (PMR). We believe that the etiology of PMR, in this case, is related to a histological damage of the valve, extreme sudden force to the papillary muscle, and some possible tissue hypo-perfusion of the subvalvular apparatus. We performed a mitral valve replacement and bypass coronary surgery with good results.