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during the ventricular electrograms of the periodic ventricular systoles 
and also during the electrograms of some “gehäufte’” extrasystoles 
(indicated in the figure by ab). Then the excitation wave would 
appear to have spread after the fibrillation over the bulbus arteriosus. 
At 2 the ventricular base is stimulated again a little past the 
summit of the 7-deflection. Again ventricular fibrillation is the con- 
sequence, while the auricles continue to pulsate in the undisturbed 
rhythm. After a short time, however, fibrillation passes into five 
“pehaufte’ extrasystoles, followed by a prolonged pause '). 
Subsequently the normal rhythm recovers itself. In what manner 
this transition occurs will be further examined by me. It has already 
appeared that the one process in the ventricle is liable to merge 
into the other, but also that this transition can occur indirectly. 
This will be recorded afterwards. 
We see then that ventricular fibrillation and ‘“gehdufte”’ extrasy- 
stoles, which are of the same genesis, may even pass into one 
another. It has thus been proved experimentally that the two rhythm- 
disturbances are closely allied. This conception has been advocated 
already by clinicians as WeNCKEBACH and Lewis. 
1) It is remarkable that this pause is of a longer duration than the one after 
the single extrasystole with which the previous fibrillation concluded. The post- 
extra-systolic pause then is very different as to duration (see also figs 1, 2 and 3) 
just as the post-undulatory pause, which may even fail altogether. To this | purpose 
to revert in a later publication. 
