Appreciation for the love of Jesus as expressed visually by the symbol of his Heart is a western development not appreciated by the Church in the east.

The heart appears in the writing of the early Church fathers, not as a separate devotion, but as illustrative of the love expressed through the heart of Jesus in the New Testament, particularly in the writings of St. John and the epistles of St. Paul, and that's actually the same way many of the artists of the early holy cards worked with the image.

Most of the later holy cards promoted devotion to the Sacred Heart, but the cards that interest me most are the earlier ones that included the Heart of Jesus simply as an element within a composition illustrating some mystery of the love of God made possible through the Incarnation.

Because many of the early holy cards used the symbol of the Heart of Jesus to illustrated the Heart to heart communion made possible by the the institution of the Eucharist, I've also included links to miracles of the Eucharist in which the Heart appears.

The history of the Heart of Jesus in western spirituality is long and complex, so I made links to some sites that I've found helpful.