Background: Recent advances in the assessment of myocardial function have facilitated the direct measurement of atrial function using speckle-tracking echocardiography. Currently, normal reference ranges for atrial function using speckle-tracking echocardiography are based on a few initial studies, with variations among modestly sized (n = 100-350) studies.

Methods: The authors searched the PubMed, Embase, and Scopus databases for the key terms "left atrial/atrial/atrium" and "strain/function/deformation/stiffness" and "speckle tracking/Velocity Vector Imaging/edge tracking." Studies of global left atrial function using speckle-tracking were selected if they involved >30 normal or healthy participants without any cardiac risk factors. Normal ranges for reservoir strain, conduit strain, and contractile strain were computed using a random-effects model. Meta-regression and subgroup analysis was performed to explore between-study heterogeneity.

Results: Forty studies (2,542 healthy subjects) satisfied the inclusion criteria. Meta-analysis revealed a normal reference range for reservoir strain of 39% (95% CI, 38%-41%, from 40 articles), for conduit strain of 23% (95% CI, 21%-25%, from 14 articles), and for contractile strain of 17% (95% CI, 16%-19%, from 18 articles). Meta-regression identified heart rate (P = .02) and body surface area (P = .003) as contributors to this heterogeneity. Subgroup analyses revealed heterogeneity due to sample size (n > 100 vs N < 100, P = .02).

Conclusions: The normal reference ranges for the three components of left atrial function are demonstrated. The between-study heterogeneity is explained partly by heart rate, body surface area, and sample size.

Item Type:	Refereed Article
Keywords:	strain, atrial, normal range, meta-analysis
Research Division:	Biomedical and Clinical Sciences
Research Group:	Cardiovascular medicine and haematology
Research Field:	Cardiology (incl. cardiovascular diseases)
Objective Division:	Health
Objective Group:	Clinical health
Objective Field:	Clinical health not elsewhere classified
UTAS Author:	Pathan, F (Dr Faraz Pathan)
UTAS Author:	D'Elia, N (Mr Nic D'Elia)
UTAS Author:	Nolan, MT (Mr Mark Nolan)
UTAS Author:	Marwick, TH (Professor Tom Marwick)
UTAS Author:	Negishi, K (Dr Kazuaki Negishi)
ID Code:	114685
Year Published:	2017
Web of Science® Times Cited:	109
Deposited By:	Menzies Institute for Medical Research
Deposited On:	2017-02-23
Last Modified:	2018-05-29
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