Three-dimensional Echocardiographic Evaluation of Right Ventricular Volume and Function in Pediatric Patients: Validation of the Technique
ABSTRACT 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.
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ABSTRACT: To evaluate transthoracic minimally invasive device closure of atrial septal defects by performing transthoracic echocardiography to measure changes in cardiac hemodynamics and loading conditions. Between January 2012 and December 2012, we performed transthoracic minimally invasive device closure of atrial septal defects in 95 patients with secundum atrial septal defects (ASD), and performed transthoracic echocardiography to measure blood flow velocities at the tricuspid valve orifice and at the pulmonary valve orifice, sizes of the left and right atria and ventricles, right ventricular fractional area change, right ventricular Tei index, three-dimensional right ventricular ejection fraction, tricuspid annular plane systolic excursion and left ventricular ejection fractions before the procedure and 1 week, 3 months, and 1 year post-procedure. Varying degrees of improvement were observed post-procedure at later time points. The maximum blood flow velocity at the pulmonary valve orifice, mean flow velocity, velocity-time integral, and A peak and E peak blood flow velocity at the tricuspid valve orifice decreased significantly post-procedure (P<0.05). In 3 months and 1 year's follow-up, the inner diameter of the middle portion of the pulmonary artery, and diameters of the right atrium and right ventricle decreased significantly post-procedure (P<0.05). The diameters of the left atrium and left ventricle increased after the procedure (P<0.05). One week after the procedure, the right ventricular fractional area change, three-dimensional right ventricular ejection fraction, right ventricular Tei index and tricuspid annular plane systolic excursion had significantly reduced compared with the preoperative data (P<0.05). While these four parameters were still decreased at the 3 months and at 1 year's follow-up, but the differences were not statistically significant compared with the 1 week's postoperative data (P>0.05). One week post-procedure, left ventricular ejection fraction had not changed significantly, but at 3 months and at 1 year post-procedure, left ejection fraction had increased significantly compared with the preoperative data (P<0.05). Echocardiographic evaluation has demonstrated that cardiac hemodynamics and loading conditions improved significantly after transthoracic minimally invasive device closure of atrial septal defects.PLoS ONE 10(7):e0128475. DOI:10.1371/journal.pone.0128475 · 3.53 Impact Factor
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ABSTRACT: Summary form only given, as follows. A new learning algorithm is presented for a mapping artificial neural network. The algorithm was discovered during experimentation with backpropagation and counterpropagation networks. The backpropagation network has an excellent way of representing the knowledge, but its learning procedure converges very slowly toward the desired solution. On the other hand, the counterpropagation network's learning behavior is very predictable and straightforward, but the knowledge acquired is somewhat deficient. The author uses the same knowledge representation as in the counterpropagation network, but the learning algorithm is modified to overcome the described deficiency
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ABSTRACT: The past three decades have seen echocardiography evolve into a cornerstone of modern cardiac investigation. Gradually, additional ultrasound-based techniques have been invented, investigated, and then integrated. A more recent development in echocardiography is three-dimensional imaging, which has permeated every aspect of traditional cardiac ultrasound. It is more than simply the latest addition to “standard” echocardiography and almost has developed into an independent imaging modality, encompassing gray-scale acquisitions, color Doppler, stress, contrast, and now even transesophageal imaging. Its utility in research has long been established, but more recent investigation has focused on its incorporation into daily clinical practice. This article summarizes the available techniques, puts them in a clinical context, and examines recent research.Current Cardiovascular Imaging Reports 09/2008; 1(1):39-48. DOI:10.1007/s12410-008-0008-z