THE MECHANISM OF THE HEART PUMP 1033 



ment of the heart's action by chloroform poisoning or otherwise, the 

 muscle fibres of the heart may be quite unable to contract against the 

 distending force represented by a pressure in the heart equal to that 

 in the aorta. Under such conditions we may have sudden heart 

 failure, which can only be relieved by diminishing the diastolic disten- 

 sion, as, e.g., by letting blood from the veins opening into the heart. 



