At what point do you need to apply a precardial stroke?

A precardial stroke is applied to a point located on the sternum 2-3 cm above the xiphoid process, with a palm clenched in the fist of the palm. The blow should be short and sharp. In this case, the elbow of the hand striking should be directed along the body of the victim. Immediately after the impact, it is necessary to find out whether the work of the heart has resumed, for which 2-3 fingers should be placed on the projection of the carotid artery.