| Objective: To observe influence on QT dispersity of application of esmolol in elderly patients with coronary heart disease undergoing noncardiac surgery. Methods: Fifty ASAⅡorⅢcoronary heart disease patients aged 60-80 yrs with body mass index <30kg/m2 undergoing noncardiac surgery were randomly divided into a experiment group (esmolol group n =25) and a control group (n = 25). Radial artery was cannulated for continous BP monitoring. MAP, HR and SpO2 were continuously monitored. Anesthesia was induced with midazolam 0.050.1mg/kg, fentanyl 6μg/ kg, vecuronium 0.1mg/kg and maintaiained with propofol 412 mg·kg-1·h-1 and vecuronium 0.060.1mg·kg-1·h-1. The patiets were mechanically ventilated (VT8-10ml/ kg, RR 12bpm, I:E1:2) after tracheal intubation. Endtidal CO2 was maintained at 25 35 mmHg. In the esmolol gro up,loading dose of esmolol was taken by intravenous injection(i.v)0.5mg/kg and esmolol maintained pumping by 25·kg-1·min-1until operation completing. We gived patients 12 leads electrocardiogram before the operation, cutting skin, 5min, 30min and 60min after cutting skin, immediately after surgery, the first and second days after the surgery. Measured longest and shortest QT interval by hand, we taked QT dispersity (QTd) and we recorded the ventricular arrhythmia. Results: compared with control group, QTd decreased significantly in the esmolol group(P<0.05) and the proportion of QTd greater than 50ms decreased significantly too ( P < 0.05). in the control group ,five in intraoperative and three in immediately after surgery patients appeared ventricular arrhythmia, but as for the experiment group without patients appreared ventricular arrhythmia. Conclusion: Operation and anesthetizing may increase QTd and ventricular arrhythmia incidence rate, while using of esmolol during surgery can decrease QTd and incidence rate of ventricular arrhythmia.
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