Echocardiographic Markers of Right Ventricle Diastolic Dysfunction in Neonates and Infants with Congenital Heart Disease

<b>Background:</b> Assessing right ventricular (RV) diastolic function by echocardiography in pediatric patients remains complex, particularly in congenital heart disease (CHD) characterized by RV pressure overload. The geometric peculiarities of the RV, respiratory influences, and age-dependent maturational changes complicate interpretation of Doppler-derived indices. This study aimed to characterize tricuspid valve (TV) pulsed-wave Doppler E/A inflow patterns in infants with CHD and RV pressure overload, evaluated shortly after surgical or percutaneous intervention. <b>Methods:</b> Echocardiographic analysis included TV E- and A-wave velocities obtained by pulsed-wave Doppler and measurement of E-wave deceleration time (EDT). Beat-to-beat variability was quantified over three consecutive cardiac cycles. Data were compared with a large cohort of age-matched healthy children. <b>Results:</b> Fifty-seven infants with CHD (35 pulmonary stenosis; 22 tetralogy of Fallot), examined 12-48 h post-intervention, were compared with 134 healthy controls. CHD patients showed markedly reduced beat-to-beat variability of both E- and A-wave velocities (<i>p</i> < 0.001 and <i>p</i> = 0.007, respectively). A three-beat E/A inversion pattern-common in neonates but variable in healthy infants-was consistently observed in CHD patients (<i>p</i> < 0.001). A-wave velocities were significantly higher (<i>p</i> < 0.001), whereas E/A ratios (<i>p</i> < 0.001) and EDT values (<i>p</i> = 0.010) were significantly lower compared with controls. <b>Conclusions:</b> Infants with CHD and RV pressure overload exhibit a characteristic Doppler pattern consisting of E/A ratio inversion, reduced beat-to-beat variability, increased A-wave velocity, and shortened E/A ratio and EDT. These findings may serve as practical and reproducible indicators of RV diastolic dysfunction in the early post-intervention period in neonates and infants.