414 Veterinary Medicine. 



The regular rhythm, normally manifested by the two sounds 

 and the silence, may be modified in the unequal irregular or in- 

 termittent contractions of the heart. Kiissmaul's paradoxical 

 pulse is one in which the pulse is more frequent but less full dur- 

 ing inspiration than expiration. It is seen in weak heart, during 

 recovery from chest diseases, in chronic pericarditis, and when 

 fibrous bands encircle the root of the aorta. Bigeminal and tri- 

 geminal when two or three beats follow each other rapidly, and 

 are separated from the preceding and succeeding beats by longer 

 intervals. This occurs in disease of the mitral valve, and in 

 other weak states of the heart. Foetal heart rhythm in which the 

 pause is shortened and the two sounds of the heart are almost 

 identical, is seen in the later stages of fevers, and in extreme dila- 

 tation. A curious aberration of rhythm is the repetitio7i of either 

 the first or second sound. If of the first sound (anapestic bruit) 

 each beat will be accompanied by three sounds the first two of which 

 resemble the first sound of health. If the second sound is repeated 

 (dactylic bruit, bruit de galop) the first sound only will be pro- 

 longed and the last two sharp and quick. The repetition of the 

 last sound is probably due to impaired nervous supply or hyper- 

 trophy of one ventricle which allows the completion of the con- 

 traction of the ventricle and .the closure of the arterial (semi- 

 lunar) valves sooner on one side than the other. If due to dimi- 

 nution of the arterial orifice which retarded the emptying of one 

 of the ventricles, the first sound would probably be accom- 

 panied by a blowing murmur. If the auriculo- ventricular valves 

 on one side were imperfect, allowing a reflux into the auricle 

 and a more rapid emptying of the ventricle, a blowing murmur 

 would equally accompany the first sound. In either of these 

 two last mentioned cases the murmur would mask or hide the 

 first of two doubled sounds. 



The repetition of the ist sound is often due to dilatation of one 

 ventricle, which in consequence is longer in reaching the same 

 sensation of plenitude, and in receiving the stimulus to- contraction. 



Morbid Sounds. Murmurs. The distinct and superadded 

 sounds heard in disease are usually designated murmurs. They 

 originate in the interior of the heart (endocardial) or externally 

 to the heart (pericardial). The endocardial sounds mostly arise 

 from some abnormal conditions of the valves or orifices and con- 



