摘要
目的探讨氟卡尼对兔左室心肌收缩力及心电活动的影响。方法采用冠状动脉灌注左室楔形组织块标本,分别施加基础刺激周长(BCL)为2 000,1 000,500 m s的刺激。同步记录用药前和0.3,1,3,6,10μmol/L氟卡尼使用后心肌收缩力和QRS波时限、QT间期、T波峰-未间期(Tp-e)间期及Tp-e/QT。结果在本实验刺激的频率范围内,心肌收缩力随频率加快而增强,但随氟卡尼浓度的升高,心肌收缩力逐渐减弱。但当BCL为500 m s时,10μmol/L氟卡尼致收缩力反较BCL 1000 m s时降低。用药前QRS波在不同刺激频率下保持稳定,但随着氟卡尼浓度的升高QRS波明显增宽,呈现明显的频率依赖性特征,加快刺激频率10μmol/L氟卡尼可引起QRS波时程电交替,并可引起室性心动过速、心室颤动。氟卡尼未引起QT间期、Tp-e间期及QT/Tp-e明显改变。结论氟卡尼明显抑制电活动传导和反转心肌收缩力随频率加快而增强的效应,易诱发心律失常。
Objective To investigate the effect of flecainide on the cardiac contractility and electrical activity in rabbit left ventricular. Methods Isolated arterially perfused rabbit left ventricular wedge preparations were used with stimulus at basic cycle length （BCL） of 2 000, 1 000, and 500 ms, respectively. The cardiac contractility and transmural ECG QRS complex, QT interval, the interval from the peak of the T wave to the end of T wave（ Tp-e）, and Tp-e/QT ratio were recorded simultaneously without flecainide or with flecainide at 0.3, 1, 3, 6, and 10μmol/L. Results The cardiac contractile force was increased proportionally with stimulating rate. However, along with the increasing concentration of flecainide, cardiac contractile force became weaker progressively and 10μmol/L flecainide could cause the contractility even weaker at BCL of 500 ms than that at BCL of 1 000 ms. The QRS duration kept stable at all stimulating rate in control. However, QRS duration got widening gradually in a use-dependent manner with the flecainide concentration increase. 10 μmol/L ticcainide could make QRS alternans and ventricular tachycardia or ventricular fibrillation at BCL of 500 ms. Flecainide did not show significant effect on QT and Tp-e intervals as well as Tp-e/QT ratio. Conclusion Flecainide could decrease electrical activity conduction and reverse positive inotropic effect of staircase, which could be the important mechanism for arrhythmoginic effect.
出处
《中国心脏起搏与心电生理杂志》
北大核心
2011年第1期57-60,共4页
Chinese Journal of Cardiac Pacing and Electrophysiology
基金
国家自然科学基金资助项目(项目编号:30870659
30971221)
关键词
心血管病学
氟卡尼
收缩力
正阶梯效应
QRS波电交替
心律失常
Cardiology
Flecainide
Contractile force
Positive inotropic effect of staircase
QRS alteanans
Arrhythmia
