In pediatric cardiomyopathies (CMs), the association between left ventricular (LV) systolic function and adverse outcomes has been largely investigated.1,2 By contrast, little is known about LV diastolic function and outcomes in CM patients.3,4 This is probably due to the challenge related to the echocardiographic assessment of diastolic function in children. Indeed, conventional parameters derived from adult studies have been shown to be suboptimal in pediatric patients.5

The assessment of left atrial (LA) function with 2D speckle-tracking echocardiography (2D-STE) has emerged as an accurate method to classify diastolic function in adults and6 to predict heart failure7 and has recently been added to guidelines.6 In children, atrial strain analysis using 2D-STE is feasible in healthy individuals and has been applied in various pathological conditions, including diabetes, congenital heart diseases such as atrial septal defect and tetralogy of Fallot, and pulmonary hypertension.8, 9, 10, 11, 12 Our group recently showed that the LA strain is more accurate than standard echo-Doppler and tissue Doppler parameters in identifying diastolic dysfunction compared to conventional parameters in children with CMs, with the ability to differentiate distinct subgroups of CMs.13 However, no data about the association between LA strain and adverse outcomes in pediatric patients have been published yet.

Thus, this study aims to assess the value of atrial myocardial deformation properties measured using 2D-STE in a retrospective multicenter registry of pediatric CMs.