Transthoracic 3-dimensional echocardiography in the assessment of subaortic stenosis due to a restrictive ventricular septal defect in double inlet left ventricle with discordant ventriculoarterial connections

Usefulness of Live/Real Time Three-Dimensional Transthoracic Echocardiography in the Characterization of Ventricular Septal Defects in Adults

In this report, we present 12 patients (range 14-76 years, mean 40 +/- 22.7 years) who underwent surgical repair of a ventricular septal defect (VSD). Location, size, and surrounding anatomy of the VSD were assessed prior to intervention in all patients with live/real time three-dimensional transthoracic echocardiography (3DTTE). In 9 patients, measurements of maximum dimension, circumference, and area by 3DTTE correlated well with the same measurements from intraoperative three-dimensional transesophageal echocardiographic (3DTEE) reconstruction. 3DTTE measurement of maximum dimension of VSDs also agreed well with maximum dimension by surgery in 10 patients. Live/real time 3DTTE accurately defined VSD location, size, and surrounding anatomy in all patients studied by us. VSD characterization by live 3DTTE agreed well with surgery descriptions and 3DTEE measurements.

Designing therapeutic strategies for patients with a dominant left ventricle, discordant ventriculo-arterial connections, and unobstructed flow of blood to the lungs

The palliation of the cyanotic child with a dominant morphologically left ventricle, discordant ventriculo-arterial connections, and obstruction to the pulmonary outflow tract has continued to evolve and mature. The evolution began in the early days of surgical palliation with the Blalock-Taussig shunt, extended to construction of cavopulmonary shunts, if required, and then to the Fontan procedure and its subsequent modifications. This journey took nearly 30 years to complete. There is increasing clinical data to document the beneficial effects of this approach, with ever-improving outcomes. Some aspects of the history of the cavopulmonary shunt have been previously reviewed in this journal and elsewhere, as have analysis of outcomes for some groups of patients considered for surgical completion of the Fontan circulation. While there has been some ongoing interest in ventricular septation since the early success of Sakakibara et al., this approach has largely been abandoned. Considerably more challenges and debate resonate in the surgical algorithms defined for patients whose hearts are characterized by a dominant left ventricle, discordant ventriculo-arterial connections, and unobstructed flow of blood to the lungs. This latter group will be the focus of this review, as will the aetiology of the myocardial hypertrophy that is particularly frequent in this group of patients, its clinical recognition, indeed its anticipation, and the multiple surgical strategies designed to prevent or treat it. All these manoeuvres are considered to optimise suitability for, and outcome from, creation of the Fontan circulation.

Three-dimensional (3D) echocardiographic analysis of congenital heart disease in the fetus: comparison with cross-sectional (2D) fetal echocardiography

OBJECTIVE

We attempted to assess the ability of Doppler-gated three-dimensional (3D) fetal echocardiography to reconstruct and display specific cardiac structures in fetuses with cardiac anomalies and to determine whether any advantage is offered by 3D sonographic cardiac examination over conventional fetal echocardiography.

DESIGN

After 2D fetal echocardiographic examination, 3D cardiac data were collected prospectively in 22 fetuses with various congenital heart defects. Their ages ranged from 19 to 35 weeks' gestation. Basic echocardiographic key views of the venoatrial, atrioventricular and ventriculoarterial connections were derived from volume data sets and selected for 3D reconstruction and analysis. Comparisons were made with 2D echocardiographic imaging of the fetal hearts and the diagnostic image quality of visualized structural details was evaluated.

RESULTS

The underlying cardiac malformation was well or satisfactorily visualized in 20 fetuses using 2D imaging. Gated 3D volume data sets enabled diagnostically acceptable visualization of all affected cardiac structures in 7 of 22 fetuses. High-quality 3D reconstruction of the site and spatial orientation of ventricular septal defects was obtained in 9 of 13 patients. Two-dimensional imaging remained the principal diagnostic modality in all cases with additional structural detail being obtained by 3D imaging in only two fetuses.

CONCLUSIONS

Three-dimensional imaging of fetal heart disease is feasible for a wide range of lesions, and may provide additional information of clinical value in a small number of cases when compared with 2D imaging.

Transthoracic three-dimensional echocardiography for the assessment of straddling tricuspid or mitral valves

BACKGROUND

The advent of 3D echocardiography has provided a technique which, potentially, could afford significant additional information over conventional cross-sectional echocardiography in the assessment of patients with straddling atrioventricular valves prior to surgical correction.

METHODS

Eight patients, aged from 1 month to 9.2 years, were examined with 3D echocardiography. All but three had discordant ventriculoarterial connections or double outlet right ventricle. Data suitable for reconstruction was acquired with transthoracic scanning. Right and left ventricular volumes were calculated in the 3D dataset.

RESULTS

3D echocardiography proved capable of defining the exact degree of straddling by imaging the proportion of tension apparatus attached to either side of the ventricular septum. It was able also to display the atrioventricular junction "en face", thus permitting identification of the precise site of insertion of the muscular ventricular septum relative to the atrioventricular junction. This made it possible first, to calculate the degree of valvar override, and second, to predict the location of the penetrating atrioventricular bundle. End-diastolic volume of the right ventricle in those with straddling tricuspid valves was 73 (61-83)% of normal, and, of the left ventricle in those with mitral valvar straddling 71 (40-97)% of normal.

CONCLUSIONS

3D echocardiography can aid in planning the optimal surgical procedure in patients with straddling or overrriding atrioventricular valves, as it provides diagnostic information superior to standard cross-sectional techniques. It also allows for exact measurement of the volumes of the respective ventricles.