Background: Left ventricular (LV) diastolic dysfunction (DD) carries worse prognosis in childhood. 2-dimensional (2-D) left atrial (LA) strain accurately categorizes DD in adults but its role in children is unknown. Thus, the aim of this study is to investigate whether LA strain and strain rate could diagnose and classify DD in children with dilated (CMD), hypertrophic (HCM) and restrictive (RCM) cardiomyopathies (CM).
Methods and results: The study includes 136 children (aged 8.8 ± 6 years): 44 with DCM, 40 with HCM, 7 with RCM and 45 healthy controls (CTRL). They underwent standard echocardiographic examination and 2-D speckle-tracking analyses (LV longitudinal peak systolic strain (LS), LA peak systolic strain and strain rate). No significant differences in mitral E/A and pulmonary S/D ratios were observed among the four groups. Although E/E' and indexed left atrial volumes were found to be significantly higher in HCM, DCM and RCM compared to CTRL (p < 0.001), they showed no significant difference among the three CM groups. LV LS values were significantly reduced in CM vs CTRL (p < 0.001) and in DCM vs HCM (p < 0.01), with no other differences between the remaining groups. LA peak systolic strain and strain rate values showed a steady and significant decrease with worsening of DD. Receiver Operating Characteristics (ROC) curves showed area under the curve of 0.976 (p < 0.001) for LA strain and 0.946 (p < 0.001) for LA strain rate, to distinguish CTRL from CMs.
Conclusions: LA strain and strain rate could be a promising tool to better understand and classify DD in children with cardiomyopathies, opening the way to its clinical use.
Keywords: atrial strain; cardiomyopathy; children; diastolic function.