THE PHYSIOLOGY OF THE HEARTBEAT 197 



ventricular rate is above normal, whereas in true heart-block the rate 

 is much below normal. By means of the electrocardiogram or by 

 polysphygmographic tracings, it can also be shown that the auricle is 

 beating with perfect regularity although very rapidly. 



In auricular fibrillation the ventricles obviously will respond at a very 

 irregular rate to the impulses transmitted to them, and the auricular 

 contractions, if examined by the methods above described, will show no 

 regular sequence. Further details of the method of eliciting these signs 

 will be described later (page 285). 



