This is a prospective, randomized, single blinded, controlled clinical trial designed to compare the clinical effects of sedation with dexmedetomidine versus propofol in patients undergoing cardiac surgery.
patients undergoing open heart surgery with the use of cardiopulmonary bypass (including coronary artery bypass grafting, valve repair/replacement, and combined)
left ventricular ejection fraction (LVEF) >40%.
preoperative atrial fibrillation
previous history of interventionally treated arrhythmias
second and third degree atrioventricular block
bradycardia with heart rate ≤50/min