Effect of sevoflurane on electrophysiological stability of ventricular myocardium in diabetic rats

Abstract

Objective To evaluate the effect of sevoflurane on the electrophysiological stability of ventricular myocardium in diabetic rats. Methods Thirty-two pathogen-free healthy adult male Sprague-Dawley rats, aged 3 months, weighing 180-220 g, were divided into 4 groups(n=8 each)using a random number table: control group(group C), sevoflurane group(group S), diabetes mellitus group(group D)and diabetes mellitus plus sevoflurane group(group D+ S). After the model of diabetes mellitus was established, the hearts were rapidly excised and perfused in a Langendorff apparatus with oxygenated(95% O2-5% CO2)K-H solution.After 15 min stabilization, the hearts were continuously perfused for 30 min with K-H solution in C and D groups and with K-H solution saturated with 2.5% sevoflurane in S and D+ S groups.At 15 min of stabilization(T0)and 15 and 30 min of perfusion(T1-2), heart rate(HR) and monophasic action potential(MAP)duration at 50% and 90% repolarization(MAPD50, MAPD90)in the two layers(endocardium, epicardium)of the anterior left ventricular wall were recorded.Transmural dispersion of repolarization(TDR)was calculated.S1S2 program-controlled stimulation was performed at the end of perfusion, and the occurrence of effective refractory period(ERP)and ventricular arrhythmia(VA)was recorded.ERP/MAPD90 was calculated. Results Compared with group C, HR was significantly decreased at T1-2 in group S, HR was significantly decreased and MAPD50 and MAPD90 in epicardium and endocardium were prolonged at T0-2 in D and D + S groups, TDR was significantly enlarged at T0 and ERP/MAPD90 was decreased in group D, and the incidence of arrhythmia and induction rate of VA were significantly increased in D and D+ S groups(P<0.05). Compared with group D, TDR was significantly decreased at T2, the incidence of arrhythmia and induction rate of VA were decreased, and ERP/MAPD90 was enlarged in group D+ S(P<0.05). Conclusion Sevoflurane can enhance electrophysiological stability of ventricular myocardium in diabetic rats and decrease the risk of ventricular arrhythmia. Key words: Anesthetics, inhalation; Diabetes mellitus; Electrocardiography; Arrhythmias, cardiac