Assessment of ventricular relaxation and stiffness using early diastolic mitral annular and inflow velocities in pediatric patients with heart disease

This study was undertaken to test the hypothesis that noninvasive echocardiographic indexes obtained using early diastolic mitral annular and inflow velocities reflect diastolic function in children. We included in this study 61 consecutive pediatric patients (age 0.4-13 years) who underwent cardiac catheterization for various heart diseases with biventricular circulation. Left ventricular (LV) pressure was measured using a high-fidelity manometer to obtain the time constant of relaxation (tau) and LV chamber stiffness (K). Echocardiography was simultaneously performed during catheterization. Data acquisition was repeated after the administration of dobutamine. The peak early mitral annular velocity (e') and tau showed a significant inverse correlation (r = -0.42). Receiver-operating characteristic (ROC) analysis to determine the 90th percentile of tau yielded an area under the curve (AUC) of 0.86 for a septal e' < 6.2 cm/s, with sensitivity and specificity of 0.83. The dobutamine-induced changes in e' closely correlated with those in tau (r = -0.69). The deceleration time (DT) showed a significant but weak negative correlation with K (r = -0.35), and ROC analysis to determine the 90th percentile of Ie yielded an AUC of 0.82 for a DT < 100 ms, with sensitivity of 0.80 and specificity of 0.77. The ratio of peak early mitral inflow velocity (E) to e' (E/e') significantly correlated with LV end-diastolic pressure (EDP; r = 0.48, P < 0.0005), and ROC analysis to determine the 90th percentile of EDP (> 12.96 mmHg) yielded an AUC of 0.81 for an E/e' > 16.4, with sensitivity of 0.71 and specificity of 0.93. The e', DT, and E/e' values in our study reflect the diastolic function in our pediatric population. However, the weak correlations between these indexes and invasive measures of diastolic function suggest that these indexes are useful in detecting diastolic dysfunction but not in determining the absolute values of diastolic dysfunction. Therefore, a future study is warranted to develop an efficient algorithm for systematic noninvasive evaluation of LV diastolic function in children.