Kaye D M, Jennings G L, Dart A M, Esler M D
Alfred Baker Medical Unit, Baker Medical Research Institute, Melbourne, Australia.
J Am Coll Cardiol. 1998 Mar 1;31(3):583-7. doi: 10.1016/s0735-1097(97)00525-1.
The present study was designed to identify the hemodynamic factor or factors that reflexly contribute to activation of the cardiac sympathetic nerves in patients with severe congestive heart failure (CHF).
We and others have previously shown that activation of the sympathetic nervous system is a key feature of CHF in humans. Furthermore, the degree of sympathetic activation shows marked regional heterogeneity and is most pronounced in the heart. Recent studies have shown a significant positive relation between pulmonary artery pressure and the magnitude of cardiac sympathetic activation. Of particular importance, the degree of cardiac sympathoexcitation has also been shown to be strongly associated with mortality in CHF.
We assessed total systemic and cardiac sympathetic activity (norepinephrine [NE] spillover method) in nine patients with severe CHF and significantly elevated pulmonary artery pressure (mean [+/-SEM] pulmonary artery pressure 46 +/- 3 mm Hg) at rest and during a titrated infusion of sodium nitroprusside (SNP).
SNP infusion significantly reduced mean arterial blood pressure, pulmonary artery pressure and pulmonary capillary wedge pressure. During SNP infusion, the total body NE spillover rate (NESR) increased (from 7.9 +/- 1.7 to 11.2 +/- 3.1 nmol/min, p < 0.01), whereas the cardiac NESR decreased (from 522 +/- 86 to 409 +/- 71 pmol/min, p < 0.05). The ratio of cardiac/total NE spillover was also substantially reduced (from 7.8 +/- 1.3 to 4.9 +/- 0.9%, p < 0.001).
There is a directionally opposite change in whole-body (increase) and cardiac (reduction) sympathetic nervous activity during SNP infusion, most likely due to unloading of arterial baroreceptors and specific cardiopulmonary baroreceptors, respectively, in severe CHF. These observations support the concept of a positive feedback relation between pulmonary artery pressure/filling pressure and cardiac sympathetic tone in CHF and serve to reinforce the importance of vasodilator therapy in this condition.
本研究旨在确定在严重充血性心力衰竭（CHF）患者中，反射性促进心脏交感神经激活的一种或多种血流动力学因素。
我们及其他研究人员先前已表明，交感神经系统激活是人类CHF的一个关键特征。此外，交感神经激活程度存在显著的区域异质性，且在心脏最为明显。最近的研究表明，肺动脉压与心脏交感神经激活程度之间存在显著正相关。特别重要的是，心脏交感神经兴奋程度也已被证明与CHF患者的死亡率密切相关。
我们评估了9例严重CHF且肺动脉压显著升高（平均[±标准误]肺动脉压46±3 mmHg）患者在静息状态及滴定输注硝普钠（SNP）期间的全身及心脏交感神经活动（去甲肾上腺素[NE]溢出法）。
输注SNP显著降低了平均动脉血压、肺动脉压和肺毛细血管楔压。在输注SNP期间，全身NE溢出率（NESR）增加（从7.9±1.7增至11.2±3.1 nmol/min，p<0.01），而心脏NESR降低（从522±86降至409±71 pmol/min，p<0.05）。心脏/全身NE溢出率的比值也大幅降低（从7.8±1.3降至4.9±0.9%，p<0.001）。
在输注SNP期间，严重CHF患者的全身（增加）和心脏（降低）交感神经活动出现方向相反的变化，最可能分别是由于动脉压力感受器和特定心肺压力感受器的负荷减轻。这些观察结果支持了CHF中肺动脉压/充盈压与心脏交感神经张力之间存在正反馈关系的概念，并进一步强调了血管扩张剂治疗在这种情况下的重要性。
