Left ventricular strain and peak systolic velocity: responses to controlled changes in load and contractility, explored in a porcine model.
Left ventricular strain and peak systolic velocity: responses to controlled changes in load and contractility, explored in a porcine model.
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DOI：
10.1186/1476-7120-10-22
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发表时间：
2012-05-28
影响因子：
1.9
通讯作者：
Haney M
中科院分区：
文献类型：
--
作者：
A'roch R;Gustafsson U;Johansson G;Poelaert J;Haney M
组织速度超声心动图越来越多地用于评价整体和局部心功能。以前的研究表明，在射血过程中获得的定量测量是收缩能力的可靠指标，尽管在不同的环境下对它们的负荷敏感性进行了研究，但仍然存在争议。我们试图表征急性负荷变化(包括前负荷和后负荷)和变力状态变化对收缩峰值速度和应变的影响，以此作为左心室收缩能力的衡量标准。对13头麻醉幼猪进行了左心室压力和容量的直接测量及经胸超声心动图检查。腔静脉球囊导管的瞬时充气产生了受控的负荷变化。在负荷改变期间，用组织速度超声心动图分析序列中至少8个连续的搏动，并分析在控制负荷变化的相同收缩状态下收缩峰值速度和应变的变化。还包括两种药物变力干预，以在每只动物中产生几种心肌收缩状态。收缩峰值速度反映了药物引起的径向和纵向收缩能力的变化。在剧烈负荷变化过程中，从纵轴和径向信号得到的收缩峰值速度保持稳定。收缩峰值速度参数与负荷或变力干预无明显相关性，即当负荷系统性、渐进性变化时(收缩峰值速度，纵轴，对照组搏动1~5.72 ± 1.36，搏动8~6.49 ± 1.28 cm/s，95%可信区间)，负性肌力干预组除负性肌力干预组在减重过程中收缩期峰速度略有下降(搏动1~3.98 ± 0.92，搏动8~2.72 ± 0.89 cm/s)。然而，收缩应变表现出明显的负荷依赖性。在这个模型中，通过逐次负荷减少测试，收缩峰值速度似乎与负荷无关，而收缩峰值应变似乎与负荷有关。在受控实验模型中，在负荷变化期间评估连续搏动的收缩峰值速度与收缩能力有很强的相关性。在该模型中，峰值收缩速度，而不是峰值应变率，在很大程度上与负荷无关。需要更多的研究来证实这一发现在临床环境中的应用。
Tissue velocity echocardiography is increasingly used to evaluate global and regional cardiac function. Previous studies have suggested that the quantitative measurements obtained during ejection are reliable indices of contractility, though their load-sensitivity has been studied in different settings, but still remains a matter of controversy. We sought to characterize the effects of acute load change (both preload and afterload) and change in inotropic state on peak systolic velocity and strain as a measure of LV contractility. Thirteen anesthetized juvenile pigs were studied, using direct measurement of left ventricular pressure and volume and transthoracic echocardiography. Transient inflation of a vena cava balloon catheter produced controlled load alterations. At least eight consecutive beats in the sequence were analyzed with tissue velocity echocardiography during the load alteration and analyzed for change in peak systolic velocities and strain during same contractile status with a controlled load alteration. Two pharmacological inotropic interventions were also included to generate several myocardial contractile conditions in each animal. Peak systolic velocities reflected the drug-induced changes in contractility in both radial and longitudinal axis. During the acute load change, the peak systolic velocities remain stable when derived from signal in the longitudinal axis and from the radial axis. The peak systolic velocity parameter demonstrated no strong relation to either load or inotropic intervention, that is, it remained unchanged when load was systematically and progressively varied (peak systolic velocity, longitudinal axis, control group beat 1-5.72 ± 1.36 with beat 8–6.49 ± 1.28 cm/sec, 95% confidence interval), with the single exception of the negative inotropic intervention group where peak systolic velocity decreased a small amount during load reduction (beat 1–3.98 ± 0.92 with beat 8–2.72 ± 0.89 cm/sec). Systolic strain, however, showed a clear degree of load-dependence. Peak systolic velocity appears to be load-independent as tested by beat-to-beat load reduction, while peak systolic strain appears to be load-dependent in this model. Peak systolic velocity, in a controlled experimental model where successive beats during load alteration are assessed, has a strong relation to contractility. Peak systolic velocity, but not peak strain rate, is largely independent of load, in this model. More study is needed to confirm this finding in the clinical setting.
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影响因子：
--
作者：
Mor-Avi, Victor;Lang, Roberto M.;Zamorano, Jose Luis
通讯作者：
Zamorano, Jose Luis
DOI：
10.1016/s0735-1097(00)01056-1
发表时间：
2001-01-01
影响因子：
24
作者：
Nagueh, SF;Sun, HB;Khoury, DS
通讯作者：
Khoury, DS
影响因子：
24
作者：
Oh, JK;Hatle, L;Little, WC
通讯作者：
Little, WC
影响因子：
1.6
作者：
Duan, YQ;Harada, K;Takada, G
通讯作者：
Takada, G
影响因子：
--
作者：
Burns, Andrew T.;La Gerche, Andre;Prior, David L.
通讯作者：
Prior, David L.