ELECTROCARDIOGRA M 



17 



Let us deal briefly with the last deflection first. This bulbus deflec- 

 tion is due to the activity of. muscle lying at the base of the ventricle ; 

 yet its direction indicates relative negativity of the apical contact. This 

 observation clearly warns us against lightly concluding that relative 



flid-|>liase. 



Fig. 6. Course of excitation wave in activation of ventricle. 



negativity at the apical contact necessarily means activity of the muscle 

 lying nearer to the base than the apex of the ventricle. The direction of 

 this deflection is what it is, because the excitation wave begins in the 

 lower part of the bulbus (i. e., toward the apical contact) and the inac- 

 tive muscle in its vicinity lies above it (i. e., toward the basal contact). 



