PDE4D and ischemia reperfusion injury: In summary, the elevated miR-542-3p expression can negatively regulate PDE4D protein expression, reduce the apoptosis of cardiomyocytes, promote the expression of cAMP and PKA in myocardial tissues, protect cardiomyocytes, and attenuate ischemia-reperfusion injury, which provides a theoretical basis and a novel therapeutic target for the treatment of ischemia-reperfusion injury.