Table_2_Normal Ranges of Right Atrial Strain and Strain Rate by Two-Dimensional Speckle-Tracking Echocardiography: A Systematic Review and Meta-Analysis.docx

Background: Normal range values of right atrial (RA) phasic function markers are essential for the identification of normal and abnormal values, comparison with reference values, and the clinical meaning of obtained values. Accordingly, we aimed to define the normal range values of RA phasic function markers obtained by 2D speckle-tracking echocardiography through a meta-analysis and determine the main sources of heterogeneity among reported values.
Methods: PUBMED, SCOPUS, and EMBASE databases were searched for the following keywords: “right atrial/right atrium” and “strain/speckle/deformation” and “echocardiography.” Studies were selected that included a human healthy adult group without any cardiovascular diseases or risk factors and that were written in the English language. For the calculation of each marker of RA phasic functions, a random-effect model was used. Meta-regression was employed to define the major sources of variabilities among reported values.
Results: Fifteen studies that included 2,469 healthy subjects were selected for analysis. The normal range values for RA strain and strain rate were 42.7% (95% CI, 39.4 to 45.9%) and 2.1 s−1 (95% CI, 2.0 to 2.1 s−1) during the reservoir phase, respectively, 23.6% (95% CI, 20.7 to 26.6%) and −1.9 s−1 (95% CI, −2.2 to −1.7 s−1) during the conduit phase, correspondingly, and 16.1% (95% CI, 13.6 to 18.6%) and −1.8 s−1 (95% CI, −2.0 to −1.5 s−1) during the contraction phase, respectively. The sources of heterogeneity for the normal range of these markers were the number of participants, the type of software, the method of global value calculation, the right ventricular fractional area change, the left ventricular (LV) ejection fraction, the RA volume index, sex, the heart rate, the diastolic blood pressure, the body mass index, and the body surface area.
Conclusions: Using 2D speckle-tracking echocardiography, we defined normal values for RA phasic function markers and identified the sources of heterogeneity as demographic, anthropometric, hemodynamic, and echocardiography factors.
Systematic Review Registration:https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42021236578, identifier: CRD42021236578.

背景：右心房（right atrial, RA）时相功能指标的正常参考范围，对于甄别正常与异常检测结果、与参考值进行比对以及明确检测所得数值的临床意义均具有重要价值。据此，本研究旨在通过荟萃分析明确经二维斑点追踪超声心动图（2D speckle-tracking echocardiography）测得的右心房时相功能指标的正常参考范围，并明确不同报道结果间异质性的主要来源。

研究方法：检索PUBMED、SCOPUS及EMBASE数据库，检索策略包含“右心房/right atrium”、“应变/speckle/变形”及“超声心动图”。筛选纳入无心血管疾病或相关危险因素的健康成人受试者队列、且以英文发表的研究。针对各项右心房时相功能指标的计算，采用随机效应模型；采用Meta回归分析明确不同报道结果间变异的主要来源。

研究结果：最终纳入15项符合标准的研究，共计2469名健康受试者用于分析。右心房储器期的应变及应变率正常参考范围分别为42.7%（95%置信区间，39.4%~45.9%）及2.1 s⁻¹（95%置信区间，2.0~2.1 s⁻¹）；管道期分别为23.6%（95%置信区间，20.7%~26.6%）及-1.9 s⁻¹（95%置信区间，-2.2~-1.7 s⁻¹）；收缩期分别为16.1%（95%置信区间，13.6%~18.6%）及-1.8 s⁻¹（95%置信区间，-2.0~-1.5 s⁻¹）。上述指标正常参考范围的异质性来源包括受试者样本量、软件类型、整体数值计算方法、右心室分数面积变化、左心室（left ventricular, LV）射血分数、右心房容积指数、性别、心率、舒张压、体质量指数及体表面积。

研究结论：本研究通过二维斑点追踪超声心动图明确了右心房时相功能指标的正常参考值，并明确异质性来源为人口统计学、人体测量学、血流动力学及超声心动图相关因素。

系统评价注册：https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42021236578，注册号：CRD42021236578。