Dexmedetomidine Pretreatment Confers Myocardial Protection and Reduces Mechanical Ventilation Duration for Patients Undergoing Cardiac Valve Replacement under Cardiopulmonary Bypass.

Purpose: The study aims to assess the effects of dexmedetomidine (Dex) pretreatment on patients during cardiac valve replacement under cardiopulmonary bypass.

Methods: For patients in the Dex group (n = 52), 0.5 μg/kg Dex was given before anesthesia induction, followed by 0.