QRS Group of the Electrocardiogram 57 



method of employing the blood-serum of the colostrum-fed, further- 

 more, does not cause colostration. 



36 (1214) 



Abnormalities in the QRS group of the electrocardiogram 

 associated with myocardial involvement. (Preliminary 

 report.) 



By B. S. Oppenheimer and M. A. Rothschild. 



[From the Car dio graphic Laboratory of Mount Sinai Hospital.] 



We have noted the association of definite peculiarities in the 

 electrocardiogram, indicative of disturbed intraventricular con- 

 duction, with such clinical conditions as are usually accompanied 

 by myocardial involvement. 



The normal electrocardiogram is to be considered the result of 

 the passage of an impulse at a normal velocity through the usual 

 channels,?, e., node of Tawara, main stem, bundle branches and ar- 

 borizations which consist of the so-called Purkinje fibers. The latter 

 form a network covering practically the entire endocardial surface 

 of the ventricles. The velocity of the impulse through Purkinje 

 fibers is at least ten times faster than its rate through ordinary 

 ventricular musculature. The impulse reaches the ventricle 

 normally through the Purkinje fibers, stimulating the ventricular 

 walls practically as a whole. An experimental injury to the 

 Purkinje fibers delays the propagation of the impulse. A lesion 

 only partially involving either bundle branch or an extensive 

 lesion of the arborizations of a branch would cause a delay in the 

 transmission of the excitation wave over the area supplied or 

 damaged. An experimental block of either right or left main 

 branch completely interrupts the passage of the impulse over 

 normal channels to the corresponding ventricle, the spread then 

 occurring through ordinary muscular connections. This gives a 

 characteristic electrocardiogram differing in many respects from 

 those to be described here which we believe to be intermediate 

 forms between the normal and those due to bundle branch block. 

 It is possible that some of the clinical records interpreted as bundle 



