Echocardiographic Assessment of Right Atrium Deformation Indices in Healthy Young Subjects

Background: Recently, assessment of the atrial motion and deformation indices obtained via Doppler myocardial imaging (DMI) has been proposed as a new method of exploring the atrial function.Objective: Our aim was to assess the right atrial (RA) regional function using myocardial velocities, strain, and strain rate imaging (SRI) and compare it with the function of the inter-atrial septum (IAS) and left atrial (LA) lateral wall in healthy young adults.Patients and Methods: A total of 75 healthy young individuals (35 women and 40 men) underwent standard transthoracic echocardiography and DMI at rest. Myocardial velocities, strain, and SRI profiles from the RA free wall, IAS, and LA lateral wall were calculated throughout the three cardiac cycles. Peak systolic, diastolic and time to peak were derived, and the average of the three cardiac cycles was taken into account for analysis in this study.Results: The RA peak systolic, peak of early, and late diastolic velocities were 9.2 ± 1.6 cm/s, -9.5 ± 1.8 cm/s, and -8.3 ± 2.1 cm/s, respectively. The RA peak systolic strain was 152% ± 51%. The RA systolic strain was significantly higher than that of the IAS (87% ± 21%, P = 0.001) and the LA lateral wall (89% ± 15%, P = 0.001). The RA peak systolic, peak early and late diastolic SR were 6.3 ± 3.0 s-1, -5.4 ± 1.7 s-1, and -4.5 ± 2.2 s-1, respectively.Conclusions: DMI proved to be a feasible and reproducible method for the assessment of the RA function in healthy young subjects. Study of myocardial properties showed that the RA free wall myocardial motion and deformation were significantly higher than those of the IAS and the LA lateral wall, but the rate of the RA free wall deformation was not significantly higher than that of the IAS and the LA lateral wall.Keywords: Right Atrium; Normal Values; Velocity; Strain; Strain Rate1. BackgroundThe right atrium (RA) is a dynamic structure with complex mechanics. William Harvey was the first to identify the atrium as a receptacle storehouse and reported that the RA was the first to live, and the last to die (1). Ideally, the RA should transfer a high volume of blood to the right ventricle (RV) rapidly at low pressure to prevent from peripheral edema and hepatic congestion (2). Assessment of active and passive atrial functions is an integral part in the examination of the cardiac function and is vital to the diagnosis and treatment of patients with primarily or secondarily affected atrial function (2-4). Recently, the regional assessment of the atrial motion and deformation properties obtained via Doppler-derived velocity a