BACKGROUND Establishing normal values and associated variations of three-dimensional speckle-tracking echocardiography- (3DSTE-) derived left ventricular (LV) strain is necessary for accurate interpretation and comparison of measurements. We aimed to perform a meta-analysis of normal ranges of LV global longitudinal strain (GLS), global circumferential strain (GCS), global radial strain (GRS), and global area strain (GAS) measurements derived by 3DSTE and to identify confounding factors that may contribute to variance in reported measures. METHODS The authors searched four databases, PubMed, Scopus, Embase, and Cochrane Library, through January 2019 using the key terms "left ventricular/left ventricle/left ventricles", "strain/deformation/speckle tracking", and "three dimensional/three-dimensional/three-dimension/three dimension/3D". Studies were included if the articles reported LV strain using 3DSTE in healthy normal subjects, either in the control group or comprising the entire study cohort. The weighted mean was estimated by using the random effects model with a 95% CI. Heterogeneity across studies was assessed using the I2 test. Effects of demographic (age), clinical, and vendor variables were assessed in a metaregression. The National Institutes of Health tools were used to assess the quality of included articles. Publication bias was examined by Begg's funnel plot and Egger's regression test. RESULTS The search yielded 895 articles. After abstract and full-text screening we included 33 data sets with 2,346 patients for meta-analysis. The reported normal mean values of GLS among the studies varied from -15.80% to -23.40% (mean, -19.05%; 95% CI, -18.18% to -19.93%; I2 = 99.0%), GCS varied from -15.50% to -39.50% (mean, -22.42%; 95% CI, -20.96% to -23.89%, I2 = 99.7%), GRS varied from 19.81% to 86.61% (mean, 47.48%; 95% CI, 41.50%-53.46%; I2 = 99.8%), and GAS varied from -27.40% to -50.80% (mean, -35.03%; 95% CI, -33.19% to -36.87%; I2 = 99.3%). Software for strain analysis was consistently associated with variations in normal strain values (GLS: P = .016; GCS: P < .001; GRS: P < .001; GAS: P < .001). CONCLUSIONS Variations in the normal ranges across studies were significantly associated with the software used for strain analysis, emphasizing that this factor must be considered in the interpretation of strain data.

中文翻译：

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成人三维斑点跟踪超声心动图对左心室应变的正常范围：系统评价和荟萃分析。

背景技术建立三维散斑跟踪超声心动图（3DSTE）衍生的左心室（LV）应变的正常值和相关变化对于准确解释和比较测量结果是必要的。我们旨在对3DSTE得出的LV总体纵向应变（GLS），总体周向应变（GCS），全局径向应变（GRS）和全局面积应变（GAS）测量值的正常范围进行荟萃分析，并确定混杂因素这可能会导致报告的指标出现差异。方法作者使用关键词“左心室/左心室/左心室”，“应变/变形/斑点追踪”和“ 研究中报告的GLS正常平均值在-15.80％至-23.40％之间（平均值为-19.05％; 95％CI为-18.18％至-19.93％; I2 = 99.0％），GLS在-15.50％之间到-39.50％（平均值为-22.42％； CI为95％，-20.96％至-23.89％，I2 = 99.7％），GRS为19.81％至86.61％（平均值为47.48％； 95％CI为41.50％- 53.46％; I2 = 99.8％）和GAS从-27.40％到-50.80％（平均值-35.03％; 95％CI，-33.19％到-36.87％; I2 = 99.3％）。应变分析软件始终与正常应变值的变化相关（GLS：P = .016； GCS：P <.001； GRS：P <.001； GAS：P <.001）。结论研究中正常范围的变化与用于应变分析的软件显着相关，强调在解释应变数据时必须考虑该因素。95％CI，-18.18％至-19.93％；I2 = 99.0％），GCS从-15.50％到-39.50％（平均值，-22.42％; 95％CI，-20.96％到-23.89％，I2 = 99.7％），GRS从19.81％到86.61％（平均为47.48％; 95％CI为41.50％-53.46％; I2 = 99.8％），GAS为-27.40％至-50.80％（平均值-35.03％; 95％CI为-33.19％至-36.87％ ； I2 = 99.3％）。应变分析软件始终与正常应变值的变化相关（GLS：P = .016； GCS：P <.001； GRS：P <.001； GAS：P <.001）。结论研究中正常范围的变化与用于应变分析的软件显着相关，强调在解释应变数据时必须考虑该因素。95％CI，-18.18％至-19.93％；I2 = 99.0％），GCS从-15.50％到-39.50％（平均值，-22.42％; 95％CI，-20.96％到-23.89％，I2 = 99.7％），GRS从19.81％到86.61％（平均为47.48％; 95％CI为41.50％-53.46％; I2 = 99.8％），GAS为-27.40％至-50.80％（平均值-35.03％; 95％CI为-33.19％至-36.87％ ； I2 = 99.3％）。应变分析软件始终与正常应变值的变化相关（GLS：P = .016； GCS：P <.001； GRS：P <.001； GAS：P <.001）。结论研究中正常范围的变化与用于应变分析的软件显着相关，强调在解释应变数据时必须考虑该因素。61％（平均值为47.48％; 95％CI为41.50％-53.46％; I2 = 99.8％），GAS为-27.40％至-50.80％（平均值为-35.03％; 95％CI为-33.19％至-36.87％； I2 = 99.3％）。应变分析软件始终与正常应变值的变化相关（GLS：P = .016； GCS：P <.001； GRS：P <.001； GAS：P <.001）。结论研究中正常范围的变化与用于应变分析的软件显着相关，强调在解释应变数据时必须考虑该因素。61％（平均值为47.48％; 95％CI为41.50％-53.46％; I2 = 99.8％），GAS为-27.40％至-50.80％（平均值为-35.03％; 95％CI为-33.19％至-36.87％； I2 = 99.3％）。应变分析软件始终与正常应变值的变化相关（GLS：P = .016； GCS：P <.001； GRS：P <.001； GAS：P <.001）。结论研究中正常范围的变化与用于应变分析的软件显着相关，强调在解释应变数据时必须考虑该因素。