THE APEX-BEAT. THE CARDIOGRAM. 



101 



pansphygmograph of Brondgeest is essentially the same as Marey's apparatus, 

 with unimportant changes. Marey's sphygmograph can also be used. In animals 

 the cardiogram can be registered by ligating the tube of the pansphygmograph in 

 the pericardium. 



In the normal tracing of the apex-beat of man (A) or of the dog (B) 

 the following details are distinguishable : a b corresponds to the period of 

 the pause and of the contraction of the auricles. As the auricles con- 

 tract in the direction of the heart's axis from the right and above to the left 

 and downward it is not surprising that the apex of the heart advances 

 toward the intercostal space. In this portion of the tracing there can 

 be seen generally two or even three slight elevations which may be due 

 to the rapidly successive contractions of the venous endings, the auricular 

 appendages, and the auricles themselves. 



Kill 



FIG. 28. A, Normal apex-beat tracing from man. B, from a dog; C, tracing of an accelerated apex-beat from 

 a dog; D and E, normal apex-beat tracings from man recorded upon a vibrating tuning-fork plate. Each 

 serration represents 0.01613 second of time. In all of the tracings a b indicates the auricular contraction, 

 b c, the ventricular contraction; d, the closure of the aortic valves; e, the closure of the pulmonary valves; 

 e f, relaxation of the ventricles. 



Naturally the last, occasionally distinct, elevation, occurring shortly before b 

 (corresponding to B v and C v in Fig. 31), will be looked upon as the true auricular 

 contraction; v. Ziemssen and Ter Gregorianz were able to register the elevation 

 of the auricular appendix preceding the auricular contraction in a woman with 

 an exposed heart. 



The line b c is caused by the ventricular contraction. It is this alone 

 that is appreciable to the palpating finger as the apex-beat. The first 

 sound of the heart commences with the beginning of the ventricular 

 contraction. 



