Interpretation of Left Ventricular Diastolic Dysfunction in Children With Cardiomyopathy by Echocardiography

BACKGROUND: Left ventricular diastolic dysfunction (DD) is a key determinant of outcomes in pediatric cardiomyopathy (CM), but remains very challenging to diagnose and classify. Adult paradigms and guidelines relating to DD are currently applied in children. However, it is unknown whether these are applicable to children with CM. We investigated the assessment of DD in children with CM using adult and pediatric echocardiographic criteria and tested whether recent adult guidelines are applicable to this population. METHODS AND RESULTS: Three investigators independently classified diastolic function in 4 study groups: controls, dilated, hypertrophic, and restrictive CM. Agreement among investigators, failure to classify DD, and the reasons for diagnostic failure were determined. The usefulness of individual echo parameters to diagnose and classify DD was assessed. One hundred seventy-five children (aged 0-18 years) were studied. DD diagnostic criteria were discrepant in the majority of patients. Delayed relaxation was diagnosed in only 14% of hypertrophic CM patients and never in dilated CM and restrictive CM, with 50% of those patients having coexisting findings of elevated filling pressures. Many key parameters, such as mitral and pulmonary venous Doppler, were not informative. Agreement among investigators for grading of DD was poor (36% of CM patients). CONCLUSIONS: Assessment of DD in childhood CM seems inadequate using current guidelines. The large range of normal pediatric reference values allows diagnosis of DD in only a small proportion of patients. Key echo parameters to assess DF are not sufficiently discriminatory in this population, and discrepancies between criteria within individuals prevent further classification and result in poor interobserver agreement.