416 



position of rest, after the completion of the T-oscillation of the 

 ventricle, before the R-osciilation of the anticipated ventricle-systole 

 begins, than after tlie extra-sliranlation at 7. The difference is little 

 but it can distinctly be observed. Entirely in conformity herewith 

 the negative T is after the extra-stimulation at 5 smaller than after 

 the extra-stimulation at 7. At 6 the anticipated ventricle-systole 

 begins, after the extra-stimulation of the auricle at a much later 

 moment of the ventricle-period. The T-oscillation remains now 

 positive, but is somewhat reduced. The extra-stimulation at 8 has 

 evidently hit the auricle at the same moment, as it was reached 

 by the sinus-impulsion. 



In these representations the enlargement of the positive T-oscil- 

 lation of the post-compensatory systoles is also the greater, in pro- 

 portion as the extra-systole of the ventricle sets in more anticipated. 



If now we try to answer the question, why the T-oscillaiions 

 of the ventricle-electrograms change the more in a negative sense 

 after extra-stimulation of the ventricle-basis and the auricle, in 

 proportion as the extra-ventricle-systole begins earlier in the ventricle- 

 period, then we must look for the cause of this phenomenon in the 

 conductivity of the ventricle. At an earlier epoch of the ventricle- 

 period this conduction is slower than al a later period. 



This is the cause that the negativity of the point at an extra- 

 systole, which hivs been brought about at an earlier epoch of the 

 ventricle-period, begins later than at an extra-systole that has been 

 brought about at a later epoch. Consequently the point-negativity 

 domineers the more in the lattei- part of the ventricle-electrograms, 

 in pi-oportion as the extra-systole has been brought about at an 

 earlier epoch of the ventricle-period. The earlier the extra-systole is 

 brought about in the ventricle-period, the more the T-oscillation 

 changes in a negatixe sense. It is likewise moreover of importance 

 in this respect that the contractility of the basis at an early epoch 

 of the ventiicle-period is still ti-ifling ; when from thei-e the contraction- 

 wave reaches the point in a slow tempo, its contractility has become 

 more intensive. But this factor can be reduced again to a slackened 

 conductivity at an early epoch of the ventricle-period. This theoretical 

 explauation corresponds so perfectly with the expeiimental results, 

 that I can discretionally produce extra-systoles with reduced positive 

 T-oscillations and with negative T-oscillations. 



1 wish to fix here the attention to one point that is distinctly 

 demonstrated iii the tigures 8 and 9, I pointed out in my former 

 communication already, that after extra-stimulation of the auricle 

 (vnd of the basis ventriculi the T-Qscillations of the ventricle- 



