VISUALIZATION OF SECUNDUM ATRIAL SEPTAL-DEFECT USING TRANSTHORACIC 3-DIMENSIONAL ECHOCARDIOGRAPHY IN CHILDREN - IMPLICATIONS FOR TRANSCATHETER CLOSURE

Background: The objective of this study was to evaluate the efficacy o f quantitative measurements of secundum atrial septal defect (ASD) wit h dynamic transthoracic three-dimensional (3-D) echocardiography. Meth ods: Twenty-six patients (age, 13 months to 14 years; mean, age, 37 mo nths) with secundum ASDs underwent 3-D echocardiographic imaging gener ated from transthoracic echocardiographic interrogation before surgery . Four specific cut planes were defined: four-chamber view, transverse view, en face view from right and Left atrial side. The images obtain ed from 16 patients clearly demonstrated all four defined cut planes f or the quantitative measurement. Results: The defect sizing determined by the 3-D images correlated well with surgical findings. These image s may be interactively manipulated to optimize visualization of the de fect to allow the cardiologist to perform transcatheter occlusion. A s ignificant correlation was demonstrated to the limbic band tissue asse ssment by four-chamber and transverse views. Unusual atrial structures such as muscle bands and the foreshortening of the en face view might induce biased measurements. Conclusions: The transthoracic approach w as successful in, capturing sufficient data to create 3-D images, whic h can provide an, accurate assessment of secundum ASD. The possibility of underestimation. should always be taken into account with the en f ace view. Multiple cut planes were essential to ensure correct sizing for adequate selection of the occluder.