Evaluation of dynamic morphology of atrial septal defect by real-time three-dimensional transesophageal echocardiography

Abstract

Objective To determine whether real-time three-dimensional transesophageal echocardiography(RT-3D TEE) is an accurate non-invasive technique for defining the morphology of atrial septal defects(ASD). Methods In 20 patients with secundum ASD, mean age 42.2 years (7 male, 13 female) ,live three dimensional surgical views of ASD were acquired,qualitative morphology of ASD such as the shape, presence of fenestrations and the defect margins were noted during the cardiac cycle. The measurements obtained from 2-dimensional transesophageal echocardiography(2D-TEE) and RT-3D TEE were compared to those obtained from stretched balloon diameter(SBD) or surgery. Measurements of the size and area change of ASD were validated during the cardiac cycle by RT-3D TEE,stepwise multiple linear regression analysis was performed to test the correlation between the maximum change ratios of area and diameter of ASD and age, atrial septal length, ASD shunting velocity, the maximum diameter of ASD and right ventricular systolic pressure. Results ① The morphology of ASD was circle-like or elliptical in systole,irregular or elliptical in diastole. ②The area and diameter of ASD measured by RT-3D TEE was minimal in isovolumetric contraction phase, maximal in isovolumetric diastole phase. The correlation coefficient of maximum diameter measured by 3D with SBD was 0.962 , greater than that by 2D and SBD (0.820). ③The change ratio of area and maximum diameter of ASD acquired by RT-3D-TEE was 11.48%-71.12% and 2.80%-43.87% respectively,and the correlation coefficient of them was 0.921. Conclusions RT-3D TEE using live 3D-Zoom mode accurately displayed the varying morphology,dimensions and spatial relations of ASD. RT-3D TEE can offer visualization morphological changing of ASD in different periods of cardiac cycle,providing more information for percutanous catheter intervention and open heart surgery. Key words: Echocardiography, transesophageal; Echocardiography, real-time three-dimensional; Heart septal defect,atrial