The standard German-suited system of leaves, acorns, hearts, and bells appears in the majority of cards from 1460 onwards.
The heart typically has a form of cardioid, the lower part of which ends in a point.
Generally, the hearts are coloured red so they can be used in some games as a pair with Diamonds (suit), like Klondike (solitaire).
The following gallery shows the hearts of a standard 52-card deck of French-suited playing cards.
The pack is of the Saxonian pattern: Four-color decks are sometimes used in tournaments or online.