Opthof T, Dekker L R, Coronel R, Vermeulen J T, van Capelle F J, Janse M J
Department of Clinical and Experimental Cardiology, Academic Medical Centre, University of Amsterdam, The Netherlands.
Cardiovasc Res. 1993 May;27(5):753-9. doi: 10.1093/cvr/27.5.753.
The aim was to assess the effects of autonomic nerve stimulation on local ventricular refractoriness by measuring local ventricular fibrillation intervals.
In 10 dogs on cardiopulmonary bypass, ventricular fibrillation intervals were recorded simultaneously at up to 32 sites before and after neural stimulation. In four dogs (group 1) the response to bilateral stellate ganglion stimulation was measured before and after bilateral cervical vagotomy. In three dogs (group 2) bilateral stellate ganglion stimulation, vagal nerve stimulation, and combined vagal and stellate ganglia stimulation were performed. In three dogs (group 3) the same protocol was applied after total decentralisation of the autonomic nervous system.
Bilateral stellate ganglion stimulation shortened the ventricular fibrillation interval at 44-50% of myocardial sites before and after vagotomy, whereas prolongation of the interval was observed at 14-18% of the sites. At higher stimulus strength shortening of the interval was measured at 85% of the sites in the intact and decentralised groups. No prolongation was observed. The shortening was largest in the decentralised group (11.1 ms). Dispersion in refractoriness increased in hearts from all groups, but not in each individual heart. Left, right, or bilateral vagal stimulation was without effect at about 75% of the tested sites. The fact that the response to autonomic nerve stimulation varies from site to site warrants our approach of simultaneous recordings at multiple sites. Dispersion in refractoriness was not affected by vagal stimulation. Combined autonomic stimulation had approximately the same effect on dispersion in refractoriness as bilateral stellate ganglion stimulation alone. However, vagal stimulation attenuated the responses to bilateral stellate ganglion stimulation by some 20% in the decentralised group.
Vagal stimulation has minor effects on ventricular refractoriness, but this is not due to sparse innervation, since vagal stimulation is able to mitigate the effects of sympathetic stimulation in decentralised hearts.
通过测量局部心室颤动间期来评估自主神经刺激对局部心室不应期的影响。
在10只接受体外循环的犬中，于神经刺激前后同时在多达32个部位记录心室颤动间期。在4只犬（第1组）中，在双侧颈迷走神经切断术前和术后测量对双侧星状神经节刺激的反应。在3只犬（第2组）中，进行双侧星状神经节刺激、迷走神经刺激以及迷走神经和星状神经节联合刺激。在3只犬（第3组）中，在自主神经系统完全去传入后应用相同方案。
双侧星状神经节刺激在迷走神经切断术前和术后使44% - 50%的心肌部位的心室颤动间期缩短，而在14% - 18%的部位观察到间期延长。在完整组和去传入组中，当刺激强度较高时，85%的部位测量到间期缩短，未观察到延长。去传入组缩短幅度最大（11.1毫秒）。所有组心脏的不应期离散度均增加，但并非每个心脏都是如此。左、右或双侧迷走神经刺激在约75%的测试部位无作用。自主神经刺激的反应因部位而异这一事实证明了我们在多个部位同时记录的方法的合理性。不应期离散度不受迷走神经刺激影响。自主神经联合刺激对不应期离散度的影响与单独双侧星状神经节刺激大致相同。然而，在去传入组中，迷走神经刺激使对双侧星状神经节刺激的反应减弱约20%。
迷走神经刺激对心室不应期影响较小，但这并非由于神经支配稀疏，因为迷走神经刺激能够减轻去传入心脏中交感神经刺激的作用。
