激活β_3肾上腺素能受体对心衰家兔室性心律失常及心率变异性、心率震荡的影响

Effects of β_3-AR activation on incidences of ventricular arrhythmia,heart rate variability and heart rate turbulence in rabbits with heart failure

目的观察给予β3肾上腺素能受体(β3-AR)激动剂及抑制剂其对心力衰竭兔心律失常及心率变异性、心率震荡的影响。方法构建容量及压力负荷型心力衰竭家兔模型,动态心电图同步记录给药期间心律失常并进行心率变异性与心律震荡分析,比较平均正常RR间期的标准差(SDNN)、低频成分(LF)、高频成分(HF)、低频与高频比值(LF/HF)、震荡初始(TO)和震荡斜率(TS)。结果给予β3-AR激动剂显著降低室性心律失常发生率(P<0.05),增加SDNN、LF、HF、LF/HF值(P<0.05)及降低TO值,增加TS值(P<0.05),给予β3-AR抑制剂可以拮抗上述效应。结论激动β3肾上腺素能受体可减少心力衰竭室性心律失常发生,可能与其对交感神经张力平衡相关。

Objective To investigate the effects ofβ3-adrenoceptor （β3-AR） activation on incidences of ven-tricular arrhythmia, heart rate variability and heart rate turbulence in rabbits with HF. Methods β3-AR agonists and in-hibitors were administrated in 24 rabbits with heart failure （HF） induced by combination of artificial aortic insufficiency and aortic constriction. 6 hours Holter monitoring was performed to evaluate incidences of ventricular arrhythmia, heart rate variability and heart rate turbulence. Results β3-AR agonists significantly prevented incidences of ventricular ar-rhythmia （P〈0.05）, enhanced SDNN, LF, HF and LF/HF （P〈0.05）, and increased the TO and flatten TS （P〈0.05）. These effects were markedly antagonized when treated with specificβ3-AR inhibitor （P〈0.05）. Conclusion β3-AR activa-tion may decrease prevalence of ventricular arrhythmia in HF through rebalance sympathetic tone.