The relative value of strain and strain rate for defining intrinsic myocardial function
The relative value of strain and strain rate for defining intrinsic myocardial function
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DOI：
10.1152/ajpheart.00429.2011
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发表时间：
2012-01-01
影响因子：
4.8
通讯作者：
D'hooge, J.
中科院分区：
文献类型：
--
作者：
Ferferieva, V.;Van den Bergh, A.;D'hooge, J.
Ferferieva V，货车d Bergh A，Claus P，Jasaityte R，Veulemans P，Pellens M，Gerche AL，Rademakers F，Herijgers P，D 'hooge J.用于定义内在心肌功能的应变和应变率的相对值。Am J Physiol Heart Circ Physiol 302：H188-H195，2012.首次发表于2011年11月11日; doi：10.1152/ajpheart.00429.2011。应变和应变率变形参数不仅是固有心肌收缩力的量度，而且还受到心脏负荷和结构变化的影响。迄今为止，没有关于这些混杂因素的相对重要性的信息。本研究旨在研究多普勒超声心动图测量的应变和应变率与决定心脏性能的个体因素之间的关系。超声心动图和电导测量同时进行的小鼠中，心脏性能的个别决定因素进行机械和/或电调制。进行多变量分析，以径向和周向应变以及收缩期径向和周向应变率峰值作为相关参数，以前负荷可复搏功（PRSW）、动脉弹性（E-a）、舒张末期压和左心室心肌容积（LVMV）作为独立因素，分别代表心肌收缩力、后负荷、前负荷和心肌容积。径向应变受E-a影响最大（β =-0.58，R-2 = 0.34），而周向应变与E-a密切相关，与LVMV中度相关（分别为β = 0.79和-0.52，R-2 = 0.54）。径向应变率与PRSW和LVMV均相关（分别为β = 0.79和-0.62，R-2 = 0.50），而周向应变率仅与PRSW显著相关（β =-0.61，R-2 = 0.51）。总之，应变（径向和周向）不是固有心肌收缩力的良好替代指标，除非考虑后负荷的强烈混杂影响。应变率是收缩性的更稳健的测量，其受心脏负荷和结构变化的影响较小。因此，收缩期峰值应变率是无创评估心肌收缩功能的更相关参数。
Ferferieva V, Van d Bergh A, Claus P, Jasaityte R, Veulemans P, Pellens M, Gerche AL, Rademakers F, Herijgers P, D'hooge J. The relative value of strain and strain rate for defining intrinsic myocardial function. Am J Physiol Heart Circ Physiol 302: H188-H195, 2012. First published November 11, 2011; doi:10.1152/ajpheart.00429.2011.-It is well accepted that strain and strain rate deformation parameters are not only a measure of intrinsic myocardial contractility but are also influenced by changes in cardiac load and structure. To date, no information is available on the relative importance of these confounders. This study was designed to investigate how strain and strain rate, measured by Doppler echocardiography, relate to the individual factors that determine cardiac performance. Echocardiographic and conductance measurements were simultaneously performed in mice in which individual determinants of cardiac performance were mechanically and/or pharmacologically modulated. A multivariable analysis was performed with radial and circumferential strains and peak systolic radial and circumferential strain rates as dependent parameters and preload recruitable stroke work (PRSW), arterial elastance (E-a), end-diastolic pressure, and left ventricular myocardial volume (LVMV) as independent factors representing myocardial contractility, afterload, preload, and myocardial volume, respectively. Radial strain was most influenced by E-a (beta = -0.58, R-2 = 0.34), whereas circumferential strain was strongly associated with E-a and moderately with LVMV (beta = 0.79 and -0.52, respectively, R-2 = 0.54). Radial strain rate was related to both PRSW and LVMV (beta = 0.79 and -0.62, respectively, R-2 = 0.50), whereas circumferential strain rate showed a prominent correlation only with PRSW (beta = -0.61, R-2 = 0.51). In conclusion, strain (both radial and circumferential) is not a good surrogate measure of intrinsic myocardial contractility unless the strong confounding influence of afterload is considered. Strain rate is a more robust measure of contractility that is less influenced by changes in cardiac load and structure. Thus, peak systolic strain rate is the more relevant parameter to assess myocardial contractile function noninvasively.