Pulmonary hypertension in sickle cell disease children under 10 years of age.

Despite the finding of elevated Tricuspid Regurgitant Velocity (TRV) in children below 5 years of age, the prevalence and evolution of Pulmonary Hypertension (PH) in young children with sickle cell disease (SCD) are unclear. In order to identify predictive factors of precocious PH development, SCD children > or =3 years old, at steady state, underwent annual echocardiography and Tissue Doppler Imaging (TDI). Patients receiving chronic transfusion were excluded. Thirty-seven of seventy-five patients were > or =3 years, with measurable TRV. In our young population (mean age 6.2 years) of mainly African, HbS/HbS patients, 8/37 (21.6%) had TRV > or =2.5 m/s, 8% being only 3 years old. Significant correlation was found between precocious TRV elevation and high platelet and reticulocyte counts and frequent acute chest syndromes (ACS). In multivariate analysis, ACS was the only variable predicting TRV > or =2.5 m/s. TDI of the 37 patients showed signs of diastolic dysfunction of the left ventricle. At follow-up all eight patients with high TRV displayed further increase and seven more developed TRV > or =2.5 m/s. PH seems to begin in children earlier than expected. Factors involved in its early onset might be different from the ones causing its development in older children or adults. African children might benefit from early screening and re-assessment once a year.

Tissue Doppler Imaging in the evaluation of abdominal aortic pulsatility: a useful tool for the neonatologist.

Sonographic cardiac evaluation of newborns with suspected aortic coarctation (AoC) should tend to demonstrate a good phasic and pulsatile flow and the absence of pressure gradient along a normally conformed aortic arch from the modified left parasternal and suprasternal echocardiographic views; these findings, however, may not necessarily rule out a more distal coarctation in the descending aorta. For this reason, the sonographic exam of newborns with suspected AoC should always include a Doppler evaluation of abdominal aortic blood flow from the subcostal view. Occasionally, however, a clearly pulsatile Doppler flow trace in abdominal aorta may be difficult to obtain due to the bad insonation angle existing between the probe and the vessel. In such suboptimal ultrasonic alignment situation, the use of Tissue Doppler Imaging instead of classic Doppler flow imaging may reveal a preserved aortic pulsatility by sampling the aortic wall motion induced by normal flow. We propose to take advantage of the TDI pattern as a surrogate of a normal pulsatile Doppler flow trace in abdominal aorta when the latter is difficult to obtain due to malalignment with the insonated vessel.

Three-dimensional echocardiographic evaluation of right ventricular volume and function in pediatric patients: validation of the technique.

The right ventricle (RV) is the main ventricular chamber in many congenital heart diseases before and after surgical correction, and it is the most important determinant of outcome in postoperative tetralogy of Fallot and other complex malformations. Unfortunately its irregular crescentic shape does not allow the use of the geometric assumption used for the left ventricle. Many methods have been suggested in the literature to overcome this problem, none fully reliable. The introduction of volume-rendered 3-dimensional (3D) reconstruction of echocardiography images provides a tool for the direct measurement of cardiac chambers, not based on geometric assumptions. The aim of this research study was to determine the accuracy of 3D echocardiography (3DE) to measure RV volumes in pediatric patients with secundum atrial septal defects, compared with direct volume measurements performed during the intervention. We performed 3DE study in the operating department, with the patient anesthetized, intubated, and ventilated before the surgical procedure. Sequential 2-dimensional echocardiographic images for subsequent 3D rendering were acquired using an ultrasound machine with a transthoracic 4-MHz rotational or 5-MHz transesophageal omniplane probe; in the last 5 patients a machine was used that was equipped with a 3600-crystal real-time 3D probe. To validate the 3DE measurements, these were compared with the volume of the RV directly measured in the operating department, at the end of the surgical procedure, injecting saline solution through the tricuspid valve, using a graduate syringe. Among 25 pediatric patients enrolled in the study, with an age range of 1 and 14 years (mean 4 years) and a weight range of 8.5 to 57.4 kg (mean 18.6 kg), in 23 a mean of 3 echocardiographic acquisitions were performed and compared with the direct measurement. A close comparison was found between RV volumes measured by 3DE and direct volume measurements (P < .00001). The regression line, shifted toward the y axis, which describes the 3DE volumes, indicated that the echocardiographic measures overestimate the surgical ones. In our study this overestimation had the mean of 9% with values comprised between 3% and 19%. The coefficient of repeatability was 4.79 mL with all the values within this range (2 SD of the mean). We conclude that 3DE provides an accurate measurement of RV volume in pediatric patients with RV volume overload. It is a reliable, noninvasive, and nongeometric method of evaluation of the volume of this chamber, and can be considered a precious tool in the armamentarium of the pediatric cardiologist.