Additional file 6: Supplementary Movie File 1. GCaMP3+ hESC-CM grafts commonly activate along vectors distinct from host tissue and with variable spatial propagation patterns. Representative cryoinjured and GCaMP3+ hESC-CM engrafted heart with the graft exhibiting beat-to-beat changes in spatial activation that are all distinct from the direction of activation in host tissue (host tissue activation not shown). In this movie, graft activation from the GCaMP3 channel is shown at one tenth speed over a still image of the injured heart oriented with the apex at the right, base at the left. Graft activation is pseudocolored black to indicate resting tissue, and white to indicate depolarized tissue. Note this GCaMP3+ H7 hESC-CM graft was uncoupled from the host heart.