ANATOMIC ASSESSMENT OF OSTIUM-SECUNDUM AT RIAL SEPTAL-DEFECTS WITH TRIDIMENSIONAL ECHOCARDIOGRAPHY

The decision to close an ostium secundum atrial septal defect by inter ventional catheterisation implies knowing its size, form and the relat ionship of its borders to neighbouring structures as accurately as pos sible. Three-dimensional echocardiography provides unique views of the interatrial septum and the authors set out to assess its performance. Ten patients, aged 8 to 20 years, included in a multicenter European clinical trial of closure of atrial septal defects with the CardioSEAL prostheses, were examined by transoesophageal echocardiography with t hree-dimensional reconstruction of the interatrial septum viewed from the left or right atrium. The septal defect had a very variable morpho logy, round, oval raquet-shaped and occasionally multiple. The surface area of these defects varied by about 70% during the cardiac cycle, m aximal during ventricular systole and minimal during atrial systole. T he maximal diameter measured by two-dimensional transoesophageal echoc ardiography underestimated that measured by three-dimensional echocard iography by about 30%. Two patients had a juxta-aortic caudal border o r a juxta-superior vena caval cephalic border making the defect unsuit able for catheter insertion of a CardioSEAL occluder. On the other han d, another patient had an adequate juxta-aortic border although it see med too narrow with conventional imaging techniques. The authors concl ude that three-dimensional reconstruction of transoesophageal echocard iography is the best method of selecting candidates for closure of ost ium septum atrial septal defect by intervantional catheterisation.