Researchers at the Hadassah University Medical Center witnessed the ability of the heart to heal itself, in the course of conducting a study on sheep where they implanted a stent into the left atrial appendage and found tissue growing inside the stent. “The tissue had a structural resemblance to tissue that was known to grow inside the atrial appendage,” reports Prof. Ronen Beeri, Director of Hadassah’s Cardiovascular Research Center and one of the study’s investigators. The researchers conducted a follow-up experiment on the hearts of adult mice. They found that what they were looking at were stem cells in the left atrial appendage which could stimulate the heart to repair itself. The researchers’ findings are also of note because they shed light on the function of the mysterious left atrial appendage.