Effect of Esketamine on Perioperative Negative Mood in Patients Undergoing Cardiac Valve Surgery

Inclusion Criteria: 1. Age ≥18 years old, male or female 2. Patients undergoing heart valve surgery 3. Patients with ASA grade 1 to 4 4. BMI between 18-30 kg/m² 5. Able to participate in neuropsychological testing and receive follow-up visits 6. Clearly understand and voluntarily agree to participate in the study and sign the informed consent form Exclusion Criteria: 1. Patients with significant preoperative neuro-psychiatric disease and cognitive impairment 2. Intellectual disability or a MiniMental State Examination (MMSE) score \<24, or a speech disorder that may compromise their ability to undergo preoperative assessments 3. History of psychoactive drug abuse 5\. Preoperative combined severe hepatic insufficiency or renal insufficiency 6. Any contraindications to ketamine or esketamine, such as refractory hypertension or hyperthyroidism