Effect of sevoflurane on electrophysiological stability of isolated rat hearts subjected to hypothermic perfusion

Abstract

Objective To evaluate the effect of sevoflurane on the electrophysiological stability of isolated rat hearts subjected to hypothermic perfusion. Methods Clean-grade healthy adult male Sprague-Dawley rats, weighing 280-360 g, were heparinized and anesthetized with pentobarbital sodium.Their hearts were excised and perfused in a Langendorff apparatus with K-H solution saturated with 95% O2-5% CO2 at 37 ℃.Twenty-four Langendorff-perfused hearts were divided into 4 groups (n=6 each) using a random number table method: control group (C group), sevoflurane group (S group), 32 ℃ hypothermia group (H group) and 32 ℃ hypothermia plus sevoflurane group (HS group). After 15 min of equilibration, the isolated hearts were continuously perfused for 30 min with K-H solution at 37 ℃, with K-H solution containing 2.3% sevoflurane at 37 ℃, with K-H solution at 32 ℃, and with K-H solution containing 2.3% sevoflurane at 32 ℃ in C, S, H and HS groups, respectively.Heart rate and monophasic action potential in three layers of the left ventricular anterior wall were recorded at 15 min of equilibration (T0) and 30 of continuous perfusion (T2), the transmural dispersion of repolarization (TDR) were calculated, and the occurrence of arrhythmia was observed. Results Compared with C and S groups, the heart rate was significantly decreased and TDR was enlarged at T1, and the incidence of arrhythmia was increased in H and HS groups (P<0.05). Compared with H group, TDR was significantly reduced at T1, and the incidence of arrhythmia was decreased in HS group (P<0.05). Conclusion Sevoflurane can improve the electrophysiological instability of isolated rat hearts subjected to hypothermic perfusion, and thus decrease the development of arrhythmia. Key words: Anesthetics, inhalation; Hypothermia; Cardiac electrophysiology