98 CARDIAC SEDATIVES 



imparting to the contractions the needful regularity and 

 strength ; while, moreover, by slowing the beats, the ven- 

 tricle is more completely filled. In dilatation of the right 

 side of the heart usually depending upon serious attacks of 

 influenza, bronchitis, or emphysema, heart tonics are seldom 

 so beneficial as in mitral disease. In the various diseases 

 for which digitalis has been used, strophanthus may be 

 given. It has little effect on peripheral vessels, is a better 

 diuretic than digitalis, but is much more toxic to the heart, 

 so that minimal doses should be used. In heart failure, 

 whether depending on nervous asthenia or on muscular 

 weakness, strychnine in continued small doses is specially 

 useful. Where there is marked irritability, it may be con- 

 joined with cocaine, and, in anaemia, with preparations of 

 iron. Where there is cardiac pain, nitrites are prescribed. 

 Where blood pressure is abnormally high, it is usually 

 desirable in vigorous subjects to relieve venous congestion 

 by purgatives or diuretics before even the most cautious 

 use of heart tonics is attempted. Lymphangitis, or inflam- 

 matory oedema, attacking usually the lymph glands and 

 vessels of the hind limbs of the heavier breeds of horses, 

 and occurring chiefly in well-fed, hard-worked animals after 

 a day's rest, is probably caused by local infection and con- 

 nected with imperfect oxidation, the consequent formation 

 of sarcolactic acid, obstruction and congestion of veins, 

 capillaries, and lymph vessels. The resulting acute inflam- 

 mation is combated by hot fomentations, a smart purgative, 

 antiseptics, and saline diuretics, while the tediously chronic 

 oedema, which is apt to follow, is removed by friction, vaso- 

 dilators, and circulatory stimulants, and regular exercise. 



CARDIAC SEDATIVES lessen the force and frequency of the 

 heart's action. For such purposes aconite, gelsemium, 

 and antimonials, or the anaesthetics and narcotic agents, 

 are chiefly prescribed. In veterinary patients aconite is 

 effectual, especially when given in small doses, at intervals 

 of two or three hours. It is chiefly used in antagonising 

 violent palpitating action of the heart, or lowering the quick, 

 full, bounding pulse, and other febrile symptoms of laryn- 

 gitis, laminitis, acute lymphargitis, and other local inflam- 

 mations. In cases of haemorrhage the narcotic agents are 



