Remedies which diminish both the force and frequency of the heartbeats, thereby producing a soothing effect, are called heart sedatives. By their depressing effect upon the heart they may be said in a certain sense to weaken its action, and if given without judgment are very dangerous. In the case of plethoric horses with high temperatures, aconite is given to slow the heart's action, but is not persisted in. Aconite, hellebore, and antimony are the chief drugs of this class.