[Terminal bundle-branch block (TBB) in acute and chronic overloading of the right heart]

The authors performed a model loading of the right heart ventricle in 40 dogs in 17 dogs--acute tension loading by creating a partial ligature (banding) of the pulmonary artery; the dogs were examined in respect to the changes hemodynamics and ECG for a period of three hours. In the second group of 10 dogs a chronic tension loading of the right heart was created by a partial ligation of the pulmonary artery (banding); the dogs were followed--up in respect to hemodynamic and vectocardiographic changes for a period of one year. In the other group of 10 dogs a chronic loading of the right heart: was formed by operative route and interatrial defect was obtained; the dogs were followed-up in respect to hemodynamics and vectrocardiographic changes for a period of one year. The authors described the changes in the intraventricular conduction of vectro cardiograms, made by the three plane system of Akulincev, and these vectrocardiograms were compared with the type and degree of loading as well as with the morphologic changes occurred in the heart. The authors indicated the nonspecificity of TBB as a sign of volume loading of the right heart ventricle.