Crystalloid vs Colloid for Hemodynamics During Anesthesia Induction in TAVR Patients

Inclusion Criteria: * Age ≥ 18 years; * Patients scheduled to undergo elective TAVR under general anesthesia; Exclusion Criteria: * Allergy to hydroxyethyl starch, its components, and/or sodium lactate Ringer's solution, or a history of colloidal allergy; * Severe cardiac dysfunction (ejection fraction\[EF\] \< 35%); * Severe renal dysfunction (creatinine \> 132 μg/L and/or requiring renal replacement therapy); * Morbid obesity (body mass index\[BMI\] \> 37.5 kg/m² or \> 32.5 kg/m² with metabolic diseases); * Severe hepatic dysfunction ; * Severe electrolyte disturbances ; * Patients with preoperative intracranial hypertension requiring dehydration therapy; * Expected postoperative hospital stay \< 24 hours; * Patients scheduled for multiple surgeries during this hospitalization.