While 15-month-old Opal is hooked up to tubes at Lurie Children's Hospital awaiting a heart transplant, her parents pray for a miracle

At 15 months, Opal Lang was reaching the typical toddler milestones like finally making it across her suburban living room without falling.

Then at a routine checkup, her pediatrician noticed when she cried out or screamed, her heart rate was irregular, said Dr. Phil Thrush, a doctor who specializes in cardiology at Lurie Children's Hospital in Chicago. In the months that followed, Opal went into cardiac arrest, had machines hooked up to her to keep her heart pumping and celebrated her second birthday in her hospital room.

Now, she is among 130 children between 1 and 5 years old across the country who are on a waiting list for a heart transplant, according to the United