与组织多普勒成像相比，心肌应变率是评估左心室心内膜下功能的更优方法。

Myocardial strain rate is a superior method for evaluation of left ventricular subendocardial function compared with tissue Doppler imaging.

作者信息

Hashimoto Ikuo, Li Xiaokui, Hejmadi Bhat Aarti, Jones Michael, Zetts Arthur D, Sahn David J

机构信息

Clinical Care Center for Congenital Heart Disease, Oregon Health and Sciences University, Portland, Oregon 97239, USA.

出版信息

J Am Coll Cardiol. 2003 Nov 5;42(9):1574-83. doi: 10.1016/j.jacc.2003.05.002.

DOI:10.1016/j.jacc.2003.05.002

PMID:14607441

Abstract

OBJECTIVES

This study was performed to evaluate subendocardial function using strain rate imaging (SRI).

BACKGROUND

The subendocardium and mid-wall of the left ventricle (LV) play important roles in ventricular function. Previous methods used for evaluating this function are either invasive or cumbersome. Strain rate imaging by ultrasound is a newly developed echocardiographic modality based on tissue Doppler imaging (TDI) that allows quantitative assessment of regional myocardial wall motion.

METHODS

We examined eight sheep using TDI in apical four-chamber views to evaluate the LV free wall. Peak strain rates (SRs) during isovolumic relaxation (IR), isovolumic contraction (IC), and myocardial strain were measured in the endocardial (End), mid-myocardial (Mid), and epicardial (Epi) layers. For four hemodynamic conditions (created after baseline by blood, dobutamine, and metoprolol infusion), we compared differences in SR of End, Mid, and Epi layers to peak positive and negative first derivative of LV pressure (dP/dt).

RESULTS

Strain rate during IC showed a good correlation with +dP/dt (r = 0.74, p < 0.001) and during IR with -dP/dt (r = 0.67, p = 0.0003). There was a significant difference in SR between the myocardial layers during both IC and IR (End: -3.4 +/- 2.2 s(-1), Mid: -1.8 +/- 1.5 s(-1), Epi: -0.63 +/- 1.0 s(-1), p < 0.0001 during IC; End: 2.2 +/- 1.5 s(-1), Mid: 1.0 +/- 0.8 s(-1), Epi: 0.47 +/- 0.64 s(-1), p < 0.0001 during IR). Also, SRs of the End and Mid layers during IC were significantly altered by different hemodynamic conditions (End at baseline: 1.7 +/- 0.7 s(-1); blood: 2.0 +/- 1.1 s(-1); dobutamine: 3.4 +/- 2.3 s(-1); metoprolol: 1.0 +/- 0.4 s(-1); p < 0.05). Myocardial strain showed differences in each layer (End: -34.3 +/- 12.6%; Mid: -22.6 +/- 12.1%; Epi: -11.4 +/- 7.9%; p < 0.0001) and changed significantly in different hemodynamic conditions (p < 0.0001).

CONCLUSIONS

Strain and SR appear useful and sensitive for evaluating myocardial function, especially for the subendocardial region.

摘要

目的

本研究旨在使用应变率成像（SRI）评估心内膜下功能。

背景

左心室（LV）的心内膜下和中层在心室功能中起重要作用。以前用于评估该功能的方法要么具有侵入性，要么很繁琐。超声应变率成像是一种基于组织多普勒成像（TDI）的新开发的超声心动图模式，可对局部心肌壁运动进行定量评估。

方法

我们使用TDI在心尖四腔视图中检查了8只绵羊，以评估左心室游离壁。在等容舒张期（IR）、等容收缩期（IC）期间的峰值应变率（SRs）以及心肌应变在心内膜（End）、心肌中层（Mid）和心外膜（Epi）层中进行测量。对于四种血流动力学状态（在基线后通过输注血液、多巴酚丁胺和美托洛尔产生）下，我们比较了End、Mid和Epi层的SR与左心室压力的峰值正负一阶导数（dP/dt）之间的差异。

结果

IC期间的应变率与 +dP/dt 显示出良好的相关性（r = 0.74，p < 0.001），IR期间与 -dP/dt 显示出良好的相关性（r = 0.67，p = 0.0003）。在IC和IR期间，心肌层之间的SR存在显著差异（IC期间：End：-3.4 +/- 2.2 s(-1)，Mid：-1.8 +/- 1.5 s(-1)，Epi：-0.63 +/- 1.0 s(-1)，p < 0.0001；IR期间：End：2.2 +/- 1.5 s(-1)，Mid：1.0 +/- 0.8 s(-1)，Epi：0.47 +/- 0.64 s(-1)，p < 0.0001）。此外，IC期间End和Mid层的SRs在不同血流动力学状态下有显著改变（基线时End：1.7 +/- 0.7 s(-1)；血液：2.0 +/- 1.1 s(-1)；多巴酚丁胺：3.4 +/- 2.3 s(-1)；美托洛尔：1.0 +/- 0.4 s(-1)；p < 0.05）。心肌应变在各层中显示出差异（End：-34.3 +/- 12.6%；Mid：-22.6 +/- 12.1%；Epi：-11.4 +/- 7.9%；p < 0.