U. Klima et al., A NEW, BIVENTRICULAR WORKING HETEROTOPIC HEART-TRANSPLANT MODEL - ANATOMIC AND PHYSIOLOGICAL CONSIDERATIONS, Transplantation, 64(2), 1997, pp. 215-222
Background. Current heterotopic heart transplant models have nonworkin
g left ventricles that atrophy and are not suitable for some studies.
We developed and characterized a new heterotopic model with working le
ft and right ventricles.Methods. Hemodynamics were compared in the wor
king and nonworking models. The influence of the length of the donor's
aorta on coronary arterial oxygenation was tested. The influence of t
he recipient's arterial pressure on developed left ventricular systoli
c pressure and the effects of alpha- and beta-adrenergic stimulation w
ere examined in both models. The nonworking and working models were co
mpared in chronic transplant preparations to investigate possible vent
ricular atrophy. Results. In this model, coronary arterial oxygen tens
ion was influenced by the length of the donor's aorta. With a short do
nor aorta (0.5 cm in the porcine model), normal coronary arterial oxyg
enation is maintained. Left ventricular systolic pressure was greater
in the working compared with the nonworking models. Left ventricular s
ystolic pressure did not respond to alpha-adrenergic stimulation but d
id respond to beta-adrenergic and combined stimulation, which indicate
s its relationship to donor heart output. Left ventricular systolic pr
essure correlated with and was determined by recipient arterial pressu
re. Ventricular atrophy occurred in the nonworking model, but ventricu
lar weight was maintained at sham control levels in this new working m
odel. Conclusion. These results demonstrate the surgical anatomic cons
iderations of a new heterotopic heart transplant model in which the le
ft and right ventricles work. Its hemodynamic performance is related t
o recipient hemodynamics, and the model responds to adrenergic stimula
tion. In chronic studies, ventricular mass is maintained, thus allowin
g this model to overcome a significant shortcoming of existing heterot
opic heart transplant models.