心肌交感神经支配与长期左心室机械性减负。

Myocardial sympathetic innervation and long-term left ventricular mechanical unloading.

机构信息

3rd Cardiology Department, University of Athens, and Division of Nuclear Medicine, Alexandra Hospital, Athens, Greece.

出版信息

JACC Cardiovasc Imaging. 2010 Jan;3(1):64-70. doi: 10.1016/j.jcmg.2009.10.008. Epub 2010 Jan 12.

DOI:10.1016/j.jcmg.2009.10.008

PMID:20129533

Abstract

OBJECTIVES

The purpose of this study was to analyze the effects of left ventricular assist devices (LVADs) on myocardial sympathetic innervation of the failing heart.

BACKGROUND

Ventricular unloading by LVADs seems to cause reverse remodeling of the failing heart, but little is known about the sympathetic nerve activity during long-term mechanical unloading.

METHODS

We studied the effects of LVADs on myocardial sympathetic innervation, by iodine 123-meta-iodobenzylguanidine (123I-mIBG) scintigraphy performed before and 3 months after LVAD implantation in 12 end-stage heart failure patients. We calculated the: 1) heart-to-mediastinum (H/M) uptake ratio on early and delayed images, indicating myocardial accumulation of 123I-mIBG; and 2) rate of 123I-mIBG washout after initial accumulation. Similar 123I-mIBG imaging and functional and hemodynamic measurements were made 3 months apart in 6 other heart failure patients not treated with an LVAD.

RESULTS

After 3 months of LVAD support, the mean left ventricular ejection fraction had increased from 19+/-6% to 29 +/- 9% (p=0.006), peak oxygen consumption increased from 9+/-4 ml/kg/min to 13+/-3 ml/kg/min (p=0.058), serum sodium increased from 135+/-4 mEq/l to 140+/-2 mEq/l (p=0.014), whereas the left ventricular end-diastolic diameter decreased from 72+/-7 mm to 56+/-3 mm (p=0.002), pulmonary capillary wedge pressure decreased from 30+/-6 mm Hg to 5+/-3 mm Hg (p=0.012), serum creatinine decreased from 1.5+/-0.6 mg/dl to 1.0+/-0.4 mg/dl (p=0.011), and B-type natriuretic peptide decreased from 2,279+/-1,900 pg/ml to 102+/-5 pg/ml (p=0.003). After 3 months of LVAD, the H/M ratio increased on delayed images from 1.25+/-0.18 to 1.43+/-0.13 (p=0.01) and on early images from 1.35+/-0.19 to 1.44+/-0.11 (p=0.028), and the washout rate decreased from 51.0+/-23.2% to 30.6+/-8.7%, (p=0.015). There was a significant correlation between the late H/M mIBG ratio and B-type natriuretic peptide (R=0.77, p=0.01) and systolic pulmonary pressure (R=0.7, p=0.05). No significant scintigraphic, functional or hemodynamic change was observed between the 2 evaluations in the 6 patients not treated with an LVAD.

CONCLUSIONS

Ventricular unloading caused clinical, functional, and hemodynamic improvements accompanied by improvements in sympathetic innervation in the failing heart.

摘要

目的

本研究旨在分析左心室辅助装置（LVAD）对衰竭心脏心肌交感神经支配的影响。

背景

LVAD 引起的心室卸载似乎导致衰竭心脏的逆重构，但对于长期机械卸载期间的交感神经活动知之甚少。

方法

我们通过在 12 例终末期心力衰竭患者中在 LVAD 植入前和植入后 3 个月进行碘 123-间碘苄胍（123I-mIBG）闪烁显像，研究了 LVAD 对心肌交感神经支配的影响。我们计算了：1）早期和延迟图像上的心脏/纵隔（H/M）摄取比值，表明 123I-mIBG 的心肌蓄积；和 2）初始蓄积后 123I-mIBG 洗脱的速率。在未接受 LVAD 治疗的另外 6 例心力衰竭患者中，每 3 个月进行一次类似的 123I-mIBG 成像和功能及血液动力学测量。

结果

在 LVAD 支持 3 个月后，左心室射血分数从 19+/-6%增加到 29 +/- 9%（p=0.006），峰值氧耗量从 9+/-4 ml/kg/min 增加到 13+/-3 ml/kg/min（p=0.058），血清钠从 135+/-4 mEq/l 增加到 140+/-2 mEq/l（p=0.014），而左心室舒张末期直径从 72+/-7 mm 减小到 56+/-3 mm（p=0.002），肺毛细血管楔压从 30+/-6 mm Hg 减小到 5+/-3 mm Hg（p=0.012），血清肌酐从 1.5+/-0.6 mg/dl 降低到 1.0+/-0.4 mg/dl（p=0.011），B 型利钠肽从 2,279+/-1,900 pg/ml 降低到 102+/-5 pg/ml（p=0.003）。在 LVAD 治疗 3 个月后，延迟图像上的 H/M 比值从 1.25+/-0.18 增加到 1.43+/-0.13（p=0.01），早期图像上的 H/M 比值从 1.35+/-0.19 增加到 1.44+/-0.11（p=0.028），洗脱率从 51.0+/-23.2%降低到 30.6+/-8.7%（p=0.015）。晚期 H/M mIBG 比值与 B 型利钠肽（R=0.77，p=0.01）和收缩期肺动脉压（R=0.7，p=0.05）呈显著相关性。在未接受 LVAD 治疗的 6 例患者中，两次评估之间未观察到闪烁照相术、功能或血液动力学的显著变化。