[Effect of ectopic excitation on pump function of the hen and dog right heart ventricle]

The pump function of the right heart ventricle has been studied in anesthetized dogs and hens at sinus rhythm, supraventricular rhythm, and subepicardial ectopic excitation of base and apex of the right and left ventricles. Dynamics of the ventricle intracavital pressure was recorded by transmural catheterization. The pump function of the right ventricle in hen (as compared with sinus rhythm) retained to the greater degree at stimulation of the left ventricle apex and deteriorated significantly at stimulation of the right ventricle, whereas in dog (as compared with supraventricular rhythm) it retained to the greater degree at stimulation of the left ventricle base and deteriorated at stimulation of the right ventricle apex. Changes of the pump function of the right heart ventricle at ectopic ventricle stimulation are similar in birds and mammals. Differences in changes of dog and hen pump functions under effect of location of the ectopic excitation seem to be due to morphofunctional peculiarities of heart ventricles.