Measurement of ASD diameter and surrounding rims using TTE in different cross sections in a patient with ASD and a deficient superior-anterior rim.

(A) Parasternal short-axis view showing measurement of the ASD diameter and the length of superior-posterior rim. The superior-anterior rim was absent. (B) Apical four chamber view showing measurement of the ASD diameter and the rim length from ASD to the mitral annulus and to the top of the atrium. (C and D) Subcostal view showing measurement of the ASD diameter, total atrial septal length, and rim length from the ASD to the mitral annulus and the superior vena cava (SVC) and inferior vena cava (IVC) entrances. Distance from “a” to “b” is the rim length of the SVC side, “c” to “d” rather than “c” to “e” is the rim length of the IVC side. The distance from “d” to “e” is the posteroinferior wall of the right atrium. ASD = atrial septal defect, AO = ascending aorta, LA = left atrium, RA = right atrium, LV = left ventricle, RV = right ventricle, IVC = inferior vena cava, SVC = superior vena cava.