Stellate Ganglion Morphine Infiltration on Myocardial I/R Injury

Inclusion Criteria: * Aged ≥18 years, Male or Female. * Acute ST-segment elevation myocardial infarction (STEMI) patients planned for percutaneous coronary intervention (PCI). Acute STEMI is defined as: electrocardiogram shows ST-segment elevation ≥0.2 mV in two or more adjacent leads, or new left bundle branch block (LBBW). * Within 24 hours of the onset of infarct-related chest pain. * Obtaining informed consent from the patient and their family. Exclusion Criteria: * Patients with severe complications of myocardial infarction, such as uncontrollable acute left heart failure and pulmonary edema, severe cardiogenic shock after cardiopulmonary resuscitation, severe mechanical complications including ventricular septal defect, papillary muscle rupture, and rupture of the left ventricular free wall; * Patients with old myocardial infarction, or cardiomyopathy, or malignant arrhythmias controlled by antiarrhythmic drugs; * Patients with coagulation disorders due to systemic diseases and those who are currently using anticoagulants and are not suitable for injection; * Patients allergic to opioids or with a history of opioid addiction and those participating in other clinical studies; * Pregnant or breastfeeding women; * Patients with severe organ dysfunction or failure, such as liver failure, renal failure, and respiratory failure; * Patients with severe infections; * Patients with severe mental illness that cannot cooperate and those taking antipsychotic drugs; * Other patients considered unsuitable for this study by the researchers.