Electrocardiographic Studies in Homologous Canine Heart Transplantations

1) In a series of ten dogs subjected to heart transplantation, serial electrocardiograms were recorded from the transplanted and the recipient hearts. 2) Approximately one week following transplantation, changes appeared in the S-T segment and the T wave of the electrocardiogram of the recipient heart without significant alteration of the QRS complexes. These findings resembled those associated with myocarditis and/or pericarditis. 3) Electrocardiographic changes did not appear in animals treated with drugs alone or in animals subjected to kidney transplantation. These findings suggest the possibility of release from transplanted hearts of an organ-specific substance or substances which affected the hearts of the recipients.