Effects of remifentanil on monophasic action potential and transmural dispersion of repolarization in rabbit myocardium / 中国病理生理杂志

ABSTRACT

AIM:To study the effect of remifentanil on monophasic action potential and transmural dispersion of repolarization (TDR) in the 3-layer myocardium of isolated rabbit hearts .METHODS:Adult rabbits (n=18, 2.0 ~2.5 kg) were used to isolate the hearts for preparing Langendorff perfusion model .The hearts were randomly divided into 3 groups after perfusion with K-H solution for 15 min the perfusion in control group ( C group ) continued for 60 min; the hearts in remifentanil group ( R group ) were perfused with 12 μg/L remifentanil K-H solution for 60 min; the hearts in remifentanil+aminophylline group ( RA group ) were given 60-min perfusion of 12 μg/L K-H remifentanil +30 mg/L aminophylline .The HR and 3 layers of myocardial monophasic action potential ( MAP) in the left ventricular anterior wall were recorded at time points after balanced infusion for 15 min ( T0 ) , and continued perfusion for 15 min ( T1 ) , 30 min ( T2 ) and 60 min ( T3 ) .The monophasic action potential duration of repolarization at 90%( MAPD90 ) and the transmural dispersion of repolarization (TDR) were calculated.The early afterdepolarization, delay afterdepolarization and arrhythmia were also observed.RESULTS:In R group, slower HR and prolonger MAPD90 and TDR at T1 ~T3 were observed as com-pared with those at T0(P<0.05).R group showed slower HR and longer MAPD 90 and TDR than C group and RA group (P<0.05).CONCLUSION:Remifentanil slows the HR, extends the MAPD90 and increases the TDR, thus being prone to induce reentry.Aminophylline makes HR faster and MAPD90 shorter, thereby reducing the TDR.