可乐定对猫心肌缺血性心律失常的影响

20只猫随机平均分为可乐定用药组及对照组,于左冠状动脉前降枝结扎,造成急性缺血性心律失常模型,预先iv可乐定15μg/kg可明显抑制室性心律失常的发生,减轻心肌超微结构的损伤,并能逆转缺血所致的左室舒张末期压升高,但对左室压力上升速率(LV±dP/dt_(max))无影响。

EFFECT OF CLONIDINE ON CAT ARRHYTHMIAS OCCURRED DURING MYOCARDIAL ISCHEMIA

Study was carried on pentobarbital anesthetized cats to investi-gate the effect of clonidine on arrhythmias induced by coronary occlusion. Clonidine 15???g/kg iv 15min prior to ligation of left anterior descending coronary artery significantly reduced the frequenecy of arrhythmias: the ventricular premature bats ( phase Ia, VPB from 80% in controls to 20%,P<0.05), the ventricular tachycardia ( phase Ia, VT from 70% in controls to O P<0.005 ) and the VT (phase Ib, from 100% in controls to 50%, P<0.05). In control group, plasma NE concentration after occlusion was greater than those before occlusion ( P<0.05 ) , clonidine decreased the plasma NE concentration and protected the fine structure of the ischemic myocardium investigated with electronic microscope. After occlusion, left ventricular end-diastolic pressure increased, clonidine could reverse these change, but haven't any effects on LV×dP/dt_MAX. It is thus concluded the arrhythmias .occured during coronary occlussion were closely related to the central sympathetic nervous system, the stimulated effect of clonidine on central alpha adrenoceptors may be of beneficial to the treatment of ischemic arrhythmias.