Development of cardiac innervation, ventricular fibrillation, and sudden infant death syndrome
Stramba-Badiale M, Lazzarotti M, and Schwartz PJ (1992) Development of cardiac innervation, ventricular fibrillation, and sudden infant death syndrome. Am J Physiol 263:5 Pt 2 H1514–22.
Abstract: The effects of bilateral vagotomy and of right, left, and bilateral stellectomy on sinus node and on ventricular fibrillation threshold (VFT) were assessed in three groups of puppies (1, 3, and 5 wk old) and one group of adult dogs. Heart rate was increased by vagotomy and reduced by right stellectomy in all groups. After vagotomy, VFT did not change in the first week, while it decreased in the third week (-21%, P < 0.0001), in the fifth week (-20%, P < 0.001) and in the adults dogs (-18%, P < 0.005). VFT was not modified by right stellectomy in the first week and in the fifth week (0%, NS), while it decreased in the third week (-28%, P < 0.05) and in the adults (-32%, P < 0.001). Left stellectomy, performed after right stellectomy, increased VFT in the third week (+52%, P < 0.05), in the fifth week (+62%, P < 0.001), and in the adults (+45%, P < 0.01). Thus removal of either vagal or right cardiac sympathetic activity increases susceptibility to ventricular fibrillation already during the first weeks of life. By contrast, removal of left sympathetic nerves increases cardiac electrical stability. These findings are consistent with the hypothesis that a developmental abnormality in cardiac innervation may play a role in the genesis of some cases of sudden infant death syndrome.
Keywords: QT interval, autonomic nervous system, right stellectomy, left stellectomy, vagotomy
Context
- Animal study in juvenile and adult canines to assess the impact of transection of the vagal nerve and removal of the stellate ganglion on cardiac arrhythmia in the effort to better understand pathogenesis of sudden infant death syndrome. Interpretation is complicated by the use of four age groups and by an experimental design that followed right stellectomy by left stellectomy after a delay.