Surgical validation of transthoracic three-dimensional echocardiography for the anatomical evaluation of atrial septal defect.

The closure of atrial septal defects by interventional catheterisation requ ires an accurate assessment of their morphology and anatomical relationship s. This study evaluated transthoracic three-dimensional echocardiography fo r the selection of atrial septal defects accessible to an occlusive prosthe sis. The transthoracic three-dimensional echocardiographic measurements of 17 pa tients (4 to 55 years) with ostium secundum atrial septal defects were comp ared with those of the surgeon in a prospective study, The maximal diameter s of the defect, the height of the interatrial septum, the distances to the superior vena cava (postero-superior border) and inferior vena cava (poste ro-inferior border), to the coronary sinus and the tricuspid valve were mea sured as a reconstruction of the interatrial septum seen from the right atr ium. The aortic border was measured from a three-dimensional view from the left atrium. Thirteen of the 17 investigations (76%) were exploitable. The diameters of the defect varied during the cardiac cycle (p = 0.0002). The r correlations between the surgical and echocardiographic measurements varied from 0.82 f or the maximal diameter to 0.6 for the postero-inferior limits, Three-dimen sional echocardiography is capable of detecting all the contra-indications of an occlusive prosthesis : 2 inadequate postero-inferior and 1 inadequate aortic borders, 9 maximal diameters which were too large, 3 insufficiently high atrial septa, 1 double atrial septal defect. The coronary sinus was o nly visualised in 1 case. Transthoracic three-dimensional echocardiography is a non-invasive techniqu e capable of improving the selection of atrial septal defects for intervent ional closure. The transoesophageal approach should be reserved for candida tes selected by the transthoracic investigation for the detection of small structures (coronary sinus) and when the transthoracic window is poor.