ABSTRACT
Objective To investigate the influence of esmolol infusion on QT dispersity(QTd)in elderly patients with coronary heart disease during perioperafive period.Methods Fifty ASA Ⅱ or Ⅲ patients with coronary heart disease aged 65-80 yr undegoing non-cardiac surgery under general anesthesia were randomly divided into 2 groups(n=25 each):control group(group C)and esmolol group(group E).Anesthesia was induced with midazolam,fentanyl and vecuronium and maintained with continuous iv infusion of propofol andvecuronium and intermittent iv boluses of fentanyl.The patients were intubated and mechanically ventilated.PETCO2 was maintained at 25-35 mm Hg.In group E a loading dose of esmolol 0.5 mg/kg was given iv over 1 min at 2 min before skin incision and was followed by esmolol infusion at 25 μg·kg-1·min-1 maintained until the end of operation.Radial artery was caunulated.MAP,HR,SpO2 and PETCO2 were continuously momtored.ECG composed of 12 leads was momtored before operation,at 30 min after skin incision,immediately after operation,and at postsurgery days 1 and 2.The longest and shortest QT intervals were measured and detected by a cardiologist not involved in the study.The QTd was calculated.The ventricular arrhythmia was also recorded.Results QTd,the incidences of QTd abnormality and ventricular arrbythmia were significantly lower in group E than in group C.Conclusion The use ofesmolol during operation may decrease QTd and prevent the occurrence ofventricular arrhythmia.