Early assessment of right ventricular systolic function after pediatric heart transplant.

RV systolic function is important early after HT; however, it has not been critically assessed in children using quantitative measures. The aim of this study was to describe the most validated and commonly used quantitative echocardiographic measures of RV systolic function early after pediatric HT and to assess associations with qualitative function evaluation and clinical factors. RV systolic function was quantified on the first post-HT echocardiogram >24 hours after cardiopulmonary bypass using two-dimensional TAPSE, Tricuspid annular S', FAC, and MPI. In 145 patients (median age 7.6 years), quantitative RV systolic function was markedly abnormal: mean TAPSE z-score -8.43 ± 1.89; S' z-score -4.36 ± 1.22; FAC 24.4 ± 8.34%; and MPI 0.86 ± 0.51. Few patients had normal quantitative function: TAPSE (0%), S' (1.2%), FAC (9.4%), and MPI (28.4%). In contrast, 48.3% were observed as normal by qualitative assessment. Most clinical factors, including diagnosis, pulmonary vascular resistance, posttransplant hemodynamics, inotropic support, and rejection, were not associated with RV function. In this large pediatric HT population, TAPSE, S', FAC, and MPI were strikingly abnormal early post-HT despite reassuring qualitative assessment and no significant association with clinical factors. This suggests that the accepted normal values of these quantitative measures may not apply in the early post-HT period to accurately grade RV systolic function, and there may be utility in adapting a concept of normal reference values after pediatric HT.

Assessment of the Melody valve in the mitral position in young children by echocardiography.

OBJECTIVES: Mitral valve replacement (MVR) in young children is limited by the lack of small prostheses. Our institution began performing MVR with modified, surgically placed, stented jugular vein grafts (Melody valve) in 2010. We sought to describe key echocardiographic features for pre- and postoperative assessment of this novel form of MVR. METHODS: The pre- and postoperative echocardiograms of 24 patients who underwent Melody MVR were reviewed. In addition to standard measurements, preoperative potential measurements of the mitral annulus were performed whereby dimensions were estimated for Melody sizing. A ratio of the narrowest subaortic region in systole to the actual mitral valve dimension (SubA:MV) was assessed for risk of postoperative left ventricular outflow tract obstruction (LVOTO). RESULTS: Melody MVR was performed at a median of 8.5 months (5.6 kg) for stenosis (5), regurgitation (3), and mixed disease (16). Preoperatively, actual mitral z scores measured hypoplastic (median -3.1 for the lateral [lat] dimension; -2.1 for the anteroposterior [AP] dimension). The potential measurements often had normal z scores with fair correlation with intraoperative Melody dilation (ρ = 0.51 and 0.50 for lat and AP dimensions, respectively, both P = .01). A preoperative SubA:MV <0.5 was associated with postoperative LVOTO, which occurred in 4 patients. Postoperatively, mitral gradients substantially improved, with low values relative to the effective orifice area of the Melody valve. No patients had significant regurgitation or perivalvar leak. CONCLUSIONS: Preoperative echocardiographic measurements may help guide intraoperative sizing for Melody MVR and identify patients at risk for postoperative LVOTO. Acute postoperative hemodynamic results were favorable; however, ongoing assessment is warranted.

Assessment of Progressive Pathophysiology After Early Prenatal Diagnosis of the Ebstein Anomaly or Tricuspid Valve Dysplasia.

In fetuses with Ebstein anomaly or tricuspid valve dysplasia (EA/TVD), poor hemodynamic status is associated with worse neonatal outcome. It is not known whether EA/TVD fetuses with more favorable physiology earlier in gestation progress to more severe disease in the third trimester. We evaluated if echocardiographic indexes in EA/TVD fetuses presenting <24 weeks of gestation are reliable indicators of physiologic status later in pregnancy. This multicenter, retrospective study included 51 fetuses presenting at <24 weeks of gestation with EA/TVD and serial fetal echocardiograms ≥4 weeks apart. We designated the following as markers of poor outcome: absence of anterograde flow across the pulmonary valve, pulmonary valve regurgitation, cardiothoracic area ratio >0.48, left ventricular (LV) dysfunction, or tricuspid valve (TV) annulus Z-score >5.6. Median gestational age at diagnosis was 21 weeks (range, 18 to 24). Eighteen fetuses (35%) had no markers for poor hemodynamic status initially, whereas only 7 of these continued to have no markers of poor outcome in the third trimester. Nine of 27 fetuses (33%) with anterograde pulmonary blood flow on the first echocardiogram developed pulmonary atresia; 7 of 39 (18%) developed new pulmonary valve regurgitation. LV dysfunction was present in 2 (4%) patients at <24 weeks but in 14 (37%) later (p <0.001). The TV annulus Z-score and cardiothoracic area both increased from diagnosis to follow-up. In conclusion, progressive hemodynamic compromise was common in this cohort. Our study highlights that care must be taken in counseling before 24 weeks, as the absence of factors associated with poor outcome early in pregnancy may be falsely reassuring.