The meaning of the Heartline symbol was to signify life force.
The heartline symbol is often found on the Zuni tribe fetish drawings of animals refer to Fetishism. It represents the breath as the life force of the animal. The heartline is depicted as an inlaid line in the shape of an arrow. This arrow is called the lifeline or heart line. The heartline begins at the mouth where breath gives life and points to the soul, or spirit, where faith and inner strength preside. The following symbol depicts the heartline through and image of a bear. The heartline is an arrow going from its head to the heart and shows the Indian warrior’s heart is strong like the bears. Similar images can be found depicting the heartline in other animals.