Pathogenesis, S,vmptoms. 



1059 



sequence tlie arterial pulse omits in spite of the additional 

 contraction of the heart. 



Symptoms. In omission of the ventricular systole a pause 

 corresponding to one heart beat can often be observed after 

 every 2 to 5 heart beats. The intermissions are, however, often 



Fig. 183. Iiiterniittent heart action in the horse. SphygmogTapli of the abdominal 

 aorta. Intermission of two successive pulse beats (Time indicated in 0.2"). 



much less frequent, only after every 10 to 15 heart beats, and 

 occasionally no regularity can be observed. Usually only one 

 heart beat is omitted, but there are cases in which 2 to 4 suc- 

 cessive heart beats are missing (Fig, 183). In many cases 

 a very feeble, dull, short heart sound is heard in the anterior 



Fig. 184. Intermiltcnt heart action and co)tfrncfio)is of the rentrirlcs. ncriirriuci at 

 (liferent times, in a horse. A Cardiograph, tlie small apices a correspond to the 

 auricular contractions, the larger bb' to tlie ventricular contractions. The auricular 

 apex persists during omission of ventricular systole. It corresponds with a of the 

 Phlebigraph B of the jugular vein (negative venous pulse). After each omission of 

 the ventricular contraction the pressure in the vein rose, because the vein was not 

 emptied. (Z time in 0.2".) 



portions of the heart, which corresponds to the persisting 

 auricular contractions, while the vigorous systolic heart sound 

 which depends upon a contraction of the ventricles is omitted. 

 The occurrence of the auricular contraction may be assumed 

 positively because the negative venous pulse at the entrance 



