右美托嘧啶预处理对离体大鼠心脏再灌注心律失常的影响

Effects of dexmedetomidine preconditioning on reperfusion arrhythmia in isolated rat hearts

目的观察右美托嘧啶预处理对缺血再灌注损伤心脏后心功能及再灌注心律失常的影响。方法取离体大鼠心脏建立Langendorff灌注模型,随机分人以下三组(每组10例):对照组,平衡后继续灌注120分钟;缺血再灌注组:平衡后灌注30分钟,随后停灌30分钟,复灌60分钟;右美托嘧啶预处理组,平衡后先以右美托嘧啶(10nmol/L)预处理,随后停灌30分钟,复灌60分钟。监测血流动力学及心电图参数,测定冠脉流出液肌钙蛋白Ⅰ水平及细胞内活性氧水平。结果与缺血再灌注组相比,右美托嘧啶预处理组心脏的左室发展压、左室内压上升/下降速率、心率增加,左室舒张末压力降低(P均<0.05);冠脉流出液肌钙蛋白Ⅰ水平和细胞内活性氧水平降低(P均<0.05);室性早搏个数、室速发作时间、室颤发作时间、再灌注心律失常评分降低(P均<0.05)。结论右美托嘧啶预处理能改善缺血再灌注损伤后离体大鼠心脏的功能及再灌注心律失常的严重程度。

Objective To observe the effects of dexmedetomidine preconditioning on cardiac function and reperfusion arrhythmia in ischemia/ reperfusion insulted hearts. Methods Isolated rat hearts were used for Langendorff model, then they were randomly assigned to three groups: control group, which was perfused for 120 min after balance;ischemia/reperfusion group, which was subjected to ischemia (30 min) followed by reperfusion (60 min) after balance and the 30 min perfusion;dexmedetomidine preconditioning group, in which the heart was preconditioninged with dexmedetomidine, then the heart was subjected to ischemia (30 min) followed by reperfusion (60 min). The hemodynamics and electrocardiogram were recorded, and cardiac troponin I level and intracellular reactive oxygen species level were measured. Results Compared with ischemia/reperfusion group, the left ventricular developed pressure,±dp/dt, and heart rate were elevated (P<0.05), while left ventricular end-diastolic pressure, cardiac troponin I level and intracellular reactive oxygen species level were decreased (P<0.05). The number of ventricular premature beats, the duration of ventricular tachycardia and ventricular fibrillation, and reperfusion arrhythmia score were decreased in dexmedetomidine preconditioning group (P<0.05). Conclusion Dexmedetomidine preconditioning may improve cardiac function and reperfusion arrhythmia in isolated rat hearts subjected to ischemia/reperfusion injury.