Piggy Back Heart

I heard this on the radio and then asked Dr. Wasser and he was able to refer me to the following website.
Ten years ago, before the breakthrough in RVADs and LVADs a two year old girl received a second heart. It essentially acted as an LVAD. The second heart was attached to her original heart and allowed the original heart to rest. Recently, the 12 year old girl's body began to reject the donor heart. The surgeons opted to remove the donor heart. Her original heart is now functioning as any normal heart.

http://news.bbc.co.uk/go/em/fr/-/2/hi/health/4904914.stm