We often look at modern medicine and take it for granted. When someone goes in for open-heart surgery it has almost become routine. Sure complications can happen and not every story has a happy ending, but it isn't as big a gamble as it used to be, say in the 40s.
Mary Daniel was diagnosed with a heart-murmur when she was just five-years-old, but it would later be properly diagnosed as Paten Ductus Arteriosus, or a leak in her heart. At the time it was a death sentence, and Mary's mother was told her daughter wouldn't make it past her 17th birthday.
Our of nowhere, an American doctor reached out to the family and offered to conduct a still experimental procedure on Mary, but there was a significant risk that she could die on the operating table. So, in late April 1949 Mary was admitted to Myrtle Street Children’s Hospital to undergo the operation.