自主神经系统对在体犬跨室壁三层心肌不应期不均一性影响的研究

为探讨自主神经系统对在体犬跨室壁三层心肌细胞不应期离散度的影响 ,分别在基础和缺血状态下 ,在交感神经和迷走神经刺激的过程中 ,用程序刺激法测定健康家犬在体心外膜心肌、中层心肌和心内膜心肌的不应期。结果 :在基础状态下 ,交感神经刺激能缩短三层心肌细胞的不应期 ,中层心肌细胞的不应期缩短最明显 ,跨室壁三层心肌不应期的离散度由 3± 2ms增加到 18± 6ms(P <0 .0 1) ;迷走神经刺激能延长三层心肌的不应期 ,心内膜心肌增加明显 ,跨室壁不应期离散度由 3± 2ms增加到 9± 4ms(P <0 .0 5 )。在急性缺血状态下 ,交感神经刺激延长三层心肌细胞的不应期 ,其中中层心肌细胞的不应期增加最明显 ,与刺激前相比 ,跨室壁不应期离散度由 4± 3ms增加到 16± 4ms(P <0 .0 1) ;迷走神经刺激对三层心肌细胞的不应期影响较小 ,与刺激前相比 ,跨室壁不应期离散度无显著变化。结论 :在基础及缺血状态下 ,交感神经刺激均能增加跨室壁不应期离散度 ;迷走神经刺激对跨室壁不应期离散度无显著影响。

Effect of Autonomic Nervous System on the Transmural Dispersion of Effective Refractory Period of Myoardium Across the Left Ventricular Wall in Vivo.

To investigate the effect of autonomic nerves on the transmural dispersion of effective refractory period(TDERP)of myocardium across the left ventricular free wall in vivo,with the programmed stimulation method,the effective refractory periods (ERPs)of epicardium(Epi)?midmyocardium(Mid) and endocardium(Endo) were measured during sympathetic and parasympathetic stimulation before acute myocardial ischemia and 10 minutes after acute myocardial ischemia in 12 open chest dogs.Results:The ERPs of Epi,Mid and Endo were shortened during sympathetic stimulation under normal condition,but the ERP of the Mid was shortened more than that of Epi or Endo,the TDERP was increased from 3±2 to 18±6 ms( P <0.01);The ERPs of Epi,Mid and Endo were prolonged during sympathetic stimulation under acute myocardial ischemia,the ERP of the Mid was prolonged more than that of Epi or Endo,the TDERP was increased from 4±3 to 16±4 ms( P <0.01).The ERPs of Epi,Mid and Endo were prolonged during parasympathetic stimulation under normal condition,the ERP of the Endo was prolonged more than that of Epi or Mid,the TDERP was increased from 3±2 to 9±4 ms( P < 0.05 );The ERPs of Epi,Mid and Endo were not affected significantly during parasympathetic stimulation under acute myocardial ischemia,the TDERP was not significantly different from that of the control( P > 0.05 ).Conclusion:Sympathetic stimulation can increase the TDERP under normal condition and under acute myocardial ischemia;parasympathetic stimulation dose not affect significantly the TDERP.