144 



Scientific Proceedings (113). 



69 (1651) 



The influence of venous return and arterial resistance on the 

 pressures within the right and left ventricles. 



By CARL J. WIGGERS. 



[From the Physiological Laboratory, Western Reserve University 

 Medical School, Cleveland, Ohio.] 



I. Argument. 



The question, is the response of the ventricle, under con- 

 ditions of equal irritability, fundamentally determined by the 

 initial length of its muscle fibers or by the initial tension exerted 

 upon them, is of general physiological importance. The related 

 question, can variations in initial volume (i.e., initial length) 

 occur independently of changes in initial tension, in the mammalian 

 heart, is of far-reaching clinical interest as well. As regards the 

 second question, the experimental results of Frank 1 and those of 

 Straub 2 supply an answer which is contradictory to that of Patter- 

 son, Piper and Starling 3 . The latter investigators believe to 

 have demonstrated that initial length alone determines the mag- 

 nitude of the cardiac response, irrespective of whether initial 

 tension is simultaneously altered in the same or reverse direction. 

 Gesell 4 holds that both factors may be concerned but seems in- 

 clined to believe that changes in initial length play their important 

 role when ventricular filling is relatively small. 



While the fact can not be denied that the bulk of evidence 

 apparently points to the conclusion that initial length funda- 

 mentally determines the magnitude of contraction in skeletal 

 muscles, it is not so clear how such changes can promptly adjust 

 the work of the heart to sudden changes in venous inflow or arterial 

 resistance — except, in so far as these length changes are primarily 

 due to changes in initial tension. This thought is suggested by 

 the following premises: The diastolic volumes of the ventricles 



1 Frank, Ztschr. f. Biol, 1895, xxxii, 370. 



2 Straub, Deut. Arch. f. klin. Med., 1914, cxv, 531; 1914, cxvi, 409. 



3 Patterson, Piper and Starling, Jour. Physiol., 1914, xlviii, 465. 



4 Gesell, Ant. Jour. Physiol., 1916, xxxix, 239; 1916, xl, 267. 



