CARDIAC INTERMITTENCY IN THE HORSE. 1 59 



hypertrophied, and its muscular substance degenerated. Some months 

 ago in the outer clinique we saw a horse in which the beats occurred 

 in groups of three, four, or five, separated by pauses equal in length to 

 two cardiac cycles. 



Whatever the duration of the series of beats or pauses, the first 

 contraction after the intermittency is almost always stronger than the 

 others. Sometimes, and particularly when the animal has just been 

 exercised, it is violent, recalling palpitation, while the second contrac- 

 tion always follows rapidl}' and at a shorter interval than the others. 



In some instances the usual cardiac stimuli fail to act, or have little 

 effect on the intermittency. If, in order to accelerate the beating of 

 the heart, the patient is trotted for a few moments, they may continue 

 as before ; but in general the intermittencies noted during rest 

 diminish in frequency, or temporarily disappear under the influence of 

 exercise. Last month I examined a patient showing this peculiarity. 

 The horse was five years old, had been bought six months before, and 

 was at first a good worker. Two months before being brought here it 

 began to lose its hard condition, showed difficulty in breathing, and was 

 ufifit for even moderate work, though it still appeared well-nourished. 

 On watching the flank, expiration was seen to be double. On ausculta- 

 tion every fourth or fifth heart-beat was found to be followed by an 

 intermittency equal in length to one or two pulsations. Both cardiac 

 sounds were abnormal, the first being prolonged and the second 

 double. After a few minutes' exercise the intermittency disappeared, 

 the beats succeeding at regular inter\-als ; but after a further few minutes 

 the arrests recurred at first at rare intervals, then more and more 

 frequently. 



During the last few years I have noted true intermittency, certainly 

 of old standing, in several horses undergoing treatment in hospital for 

 external diseases, but which had never shown symptoms of heart 

 disease. I will describe two cases. 



In 1895 we had in the infirmary a horse sufl'ering from picked-up 

 nail, which showed intermittency of the pulse and arrest of the heart ; 

 neither condition, I need scarcely say, had any causal connection with 

 the injury. The heart-beats occurred in series of three to six, sepa- 

 rated by silent periods of uniform length, lasting as long as one pulsation. 

 The first systole of each series was sudden, bounding, and immediately 

 followed by a second much weaker contraction, then by others of 

 diminishing strength. The \iolent struggles during operation, and 

 the traumatic fever which followed it, had no effect on the intermit- 

 tency. The animal left here in the same condition as when it entered ; 

 the periodicity and duration of the arrests were precisely the same. 



