[The right bundle branch blocks with posterior loop (author's transl)].

The AA. have analysed 39 VCG which show terminal slowed down forces definitely directed towards the right and the back. It is presumed that such electrical patterns have to be classified amongst defects which deal with right intraventricular conduction. Both the ECG and UCG test have been classified in groups: some of them simulating BFA, others BFP. An analysis of the different developing ways of the vectorial loops has been made. The AA. think that in some cases the particular direction of the terminal forces could be compatible with an isolated and zonal right conduction defect in the posterior region of the right ventricle. In other cases the coexisting electrical pathology of the left ventricle is likely to be responsible for it. At the end the distinguishing diagnostic criteria of the ECG are discussed.