The mechanism of adaptation of left atrial stretch receptors in dogs with chronic congestive heart failure.
The mechanism of adaptation of left atrial stretch receptors in dogs with chronic congestive heart failure.
复制标题
慢性充血性心力衰竭犬左心房牵张感受器的适应机制。
DOI：
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发表时间：
1977
影响因子：
15.9
通讯作者：
J. P. Gilmore
中科院分区：
文献类型：
--
作者：
I. Zucker;A. Earle;J. P. Gilmore
慢性充血性心力衰竭（CHF）是由在肾动脉水平下建造主动脉-腔静脉瘘引起的。主动脉-腔静脉瘘犬表现出慢性心力衰竭的症状，包括腹水、后肢水肿和肺充血。心室导管检查显示，与假手术对照组相比，CHF犬左室舒张末期压显著升高，左室压力发展的最大速度/左室舒张末期压显著降低。CHF犬的心脏重量/体重比显著升高。来自颈迷走神经的有髓质左心房B型受体的电生理记录表明，与假手术对照犬相比，CHF犬对这些受体的敏感性降低。对于任何给定的左房压变化，与假手术对照组相比，CHF犬左房受体的放电明显减少。研究了这种敏感性降低的机制。左心耳声速测量显示慢性CHF犬左心耳顺应性降低。此外，显微镜检查左心内膜未包封的复杂受体末梢，发现受体形态有明显改变。最典型的发现是末端树杈的丧失。综上所述，主动脉-腔静脉瘘引起的慢性心力衰竭导致左心房牵张受体反应下降，左心房顺应性下降和受体末端的结构改变可能是导致这种敏感性下降的原因。
Chronic congestive heart failure (CHF) was induced in dogs by the construction of an aorto-caval fistula below the level of the renal arteries. Aorto-caval fistula dogs showed signs of CHF which included ascites, hind limb edema, and pulmonary congestion. Ventricular catheterization indicated a significantly higher left ventricular end diastolic pressure and lower maximum velocity of left ventricular pressure development/left ventricular end diastolic pressure in CHF dogs when compared to sham-operated controls. Heart weight/body weight ratios were significantly higher in CHF dogs. Electrophysiological recordings from medullated left atrial type B receptors from the cervical vagus indicated a depressed sensitivity of these receptors in CHF dogs when compared to sham-operated control dogs. For any given change in left atrial pressure, the discharge of left atrial receptors was significantly reduced in CHF dogs compared with sham-operated controls. The mechanism for this depressed sensitivity was investigated. Sonomicrometry of the left atrial appendage indicated a decreased compliance of the left atrial appendage in the dogs with chronic CHF. In addition, microscope examination of the complex unencapsulated receptor endings taken from the left atrial endocardium indicated a marked alteration in receptor morphology. A loss of the end arborization was the most typical finding. It is concluded that chronic CHF brought about by an aorto-caval fistula results in a depressed left atrial stretch receptor response and that both decreased left atrial compliance and structural alterations in the receptor endings may account for this depressed sensitivity.