急性应激对山羊室性心律失常及心率振荡影响

Effect of acute stress on ventricular arrhythmias and heart rate turbulence of goats

目的观察急性应激时山羊室性心律失常及心率振荡改变,探索应激性心律失常机制及预防途径。方法采用噪音、红色闪光复合刺激为应激原,高效液相色谱法测定血浆去甲肾上腺素水平,MGY-H12L分析系统对动态心电图结果进行自动扫描、分析。结果与对照组相比,急性应激组、美托洛尔干预组山羊血浆去甲肾上腺素浓度随刺激时间延长进行性升高。急性应激山羊室性早搏显著增多,但无室性心动过速等严重室性心律失常出现;美托洛尔干预山羊心率显著降低,室性早搏明显减少,但仍显著多于对照组。急性应激山羊TO负值、TS显著低于对照组,美托洛尔干预组山羊TO负值增加,TS未明显增加。结论复合应激后山羊交感神经明显兴奋,心率振荡降低,室性心律失常显著增多,美托洛尔干预可拮抗交感神经激活,降低应激性室性心律失常风险。

[ Objective ] To investigate change of ventricular arrhythmias and heart rate turbulence in acute stress goats and to explore mechanism and prophylactic measures of stressful arrhythmias. [ Methods ] Complex stimuh with noise and red flashing light were introduced as stressor. Plasma norepinephrine concentration was measured by high performance liquid chromatogram. The results of dynamic electrocardiogram were scanned and analyzed automatedly with MGY-H12L analysis system. [Results] Compared with control goats, plasma norepinephrine concentration of acute stress and metoprolol group increased progressively with elongation of stimulating. Premature ventricular contractions increased significantly in acute stress goats, but no severe ventricular arrhythmias appeared. Heart rate and premature ventricular contractions of metoprolol group decreased apparently. However, premature ventricular contractions were still more than those of control goats. Negative value of turbulence onset and turbulence slope of acute stress goats were lower than control goats remarkably. Negative value of turbulence onset in metoprolol group increased, but turbulence slope didn＇t increase significantly. [ Conclusions ] Sympathetic nerve of goats with complex stress was excited apparently, and heart rate turbulence decreased, and premature ventricular contractions increased significantly. Metoprolol intervention counteracts activation of sympathetic nerve, and decreases risk of stressful ventricular arrhythmias.