466 



Drs. T. L. Brunton and T. Cash. 



to the last third of the summit of the curve in the accompanying 

 tracing, and persisting past the maximum of systole. 



Fig. 10. 



Stimulation of the Ventricle (minimal). Opening stimulation only effective. 



It is, therefore, always longer than in the normal heart. After the 

 refractory period has passed, stimulation causes reduplication of the 

 ventricular beat. The later on in the diastole that the stimulus falls 

 the shorter is the latency. 



Ventricular Stimulation — Maximal. 



Stimulation sometimes causes omission when applied at the very 

 commencement of systole. All stimulation thereafter applied causes 

 a reduplication of the ventricular systole, with a latency that becomes 

 shorter the later the stimulation is applied. If auricular reduplication 

 occurs it is always sequential to ventricular (fig. 11, a). Stimulation 



Fig. 11. 



b. 



Stimulation of the Ventricle (maximal). 



at the maximum of systole may cause a blending with the reduplicated 

 beat closely resembling one prolonged systole (fig. 11, b). The induced 

 beat is most perfect when stimulation falls, just as the abscissa is 



