Non-invasive detection of acute allograft rejection in children by tissue Doppler imaging: myocardial velocities and myocardial acceleration during isovolumic contraction.

BACKGROUND: In adults, an acute decrease of regional myocardial velocities is a sensitive marker of rejection. In children, velocities are more variable. A new marker, myocardial acceleration during isovolumic contraction (IVA), appears to be less age-dependent than myocardial velocities. This study therefore compared tissue Doppler (TDI)-derived velocities and IVA as potential rejection markers for children. METHODS: TDI was performed in 15 pediatric heart transplant recipients (age 8.0 +/- 3.6 years) during acute rejection and at baseline without rejection, 50 additional transplant children without rejection (7.8 +/- 5.9 years) and 30 age-matched healthy children (7.5 +/- 5.2 years). Color Doppler cine-loops of 3 cardiac cycles were stored as echocardiographic raw data. Using off-line post-processing, systolic (S) and diastolic (E) myocardial velocities and IVA were measured in 5 basal left ventricular segments. IVA is the peak isovolumic contraction wave velocity divided by acceleration time. RESULTS: Without rejection, transplant children had significantly lower diastolic velocities (basal lateral E 10.4 +/- 2.9 vs 11.9 +/- 2.6 cm/s; p < 0.001) and systolic velocities (S 5.6 +/- 1.4 vs 7.1 +/- 2.0 cm/s; p < 0.001) than normal age-matched controls, but IVA was similar (1.2 +/- 1.4 vs 1.3 +/- 0.5 m/s2). During rejection, all markers decreased significantly compared with age-matched normal control, the non-rejecting transplant group and individual baseline values. CONCLUSIONS: Regional myocardial velocities change significantly during acute allograft rejection in children. However, many children already have wall motion abnormalities at baseline, so results are often difficult to interpret. In contrast, isovolumic acceleration was normal without rejection and selectively decreased during the event. IVA is a promising non-invasive rejection marker for pediatric patients.

Double-orifice mitral valve with intact atrioventricular septum: an echocardiographic study with anatomic and functional considerations.

We identified 18 patients with double-orifice mitral valve (DOMV) and intact atrioventricular (AV) septum out of 40,179 echocardiographic studies performed between 1997 and 2002 at Children's Hospital, Denver, CO. In this study we describe (1) the anatomic characteristics of the DOMV in the absence of AV septal defect, (2) the function of the mitral valve by spectral and color Doppler flow mapping, and (3) associated lesions. The topographic location of the orifices in the leaflets suggests possible embryologic mechanisms of DOMV. In this series, DOMV was most commonly associated with left-sided obstructive lesions (in 39% of patients). Spectral and color Doppler interrogation demonstrated a normal flow profile in most cases; only 2 patients had significant mitral regurgitation or stenosis. Therefore, due to the uncertain natural history of this lesion and the potential need for endocarditis prophylaxis, careful imaging of the mitral valve is recommended, particularly in the presence of left-sided obstructive lesions.

Longitudinal motion of the atrioventricular annuli in children: reference values, growth related changes, and effects of right ventricular volume and pressure overload.

The goals of this study were to characterize normal patterns of longitudinal motion of atrioventricular annuli in the young, establish reference values and assess growth-related changes (n = 40). Sensitivity to changes in right ventricular volume and pressure load was assessed in patients with atrial septal defect (ASD) (n = 25) and with primary pulmonary hypertension (PPH) (n = 20). M-mode of the annuli were obtained from apical views. In healthy subjects, longitudinal %displacement decreased with growth, lateral tricuspid annulus had highest %displacement, velocity of annular descent did not change with growth, tricuspid lateral annulus had the highest velocity of descent, only ascent velocity of the lateral tricuspid annulus decreased with growth, velocities of ascent for the lateral annuli were similar and higher than the septum, and heart rate had no effect on parameters tested. In patients with ASD, the findings were an exaggerated normal pattern. In patients with PPH, %displacement and ascent velocities were blunted. Our results demonstrate the utility of this technique to assess annular dynamics in pediatric patients.

Mixed total anomalous pulmonary venous connection: Case report with bilateral venous collectors.

We present a case report of a 3-month-old boy with a mixed total anomalous pulmonary venous connection. The patient had situs solitus, small atrial septal defect, and 2 separate venous collectors. The right pulmonary veins drained through a right-sided venous collector into the coronary sinus. The left-sided pulmonary veins drained through the left-sided venous collector directly into the right superior vena cava. The use of the echocardiogram and Doppler color flow mapping to establish a detailed morphologic analysis, the sites of connection, and the presence of pulmonary venous obstructions as well as the value of this information to facilitate a successful surgical repair are discussed.