Sensitivity of two-dimensional echocardiography in the direct visualization of atrial septal defect utilizing the subcostal approach: experience with 154 patients.

In the standard precordial echocardiographic imaging planes, there is frequent dropout of atrial septal echoes in the region of the fossa ovalis that can be minimized by use of the subcostal imaging approach. The diagnostic sensitivity of this approach was reviewed in 154 patients (mean age 31 years, range 2 months to 74 years) with documented atrial septal defect in whom a satisfactory image of the atrial septum could be obtained. Subcostal two-dimensional echocardiography successfully visualized 93 (89%) of the 105 ostium secundum atrial septal defects, all 32 (100%) ostium primum defects and 7 (44%) of the 16 sinus venosus defects. A defect was not visualized (false negative response) in 12 patients (11%) with an ostium secundum defect and in 9 patients (56%) with a sinus venosus defect. In three of the former and five of the latter, a two-dimensional echocardiographic contrast examination established the presence of the interatrial shunt. Twenty-four patients (16%) with clinical findings of uncomplicated atrial septal defect confirmed by two-dimensional echocardiography underwent surgical repair of the defect without preoperative cardiac catheterization. There were no perioperative complications. Two-dimensional echocardiographic examination of the atrial septum utilizing the subcostal approach is the preferred method for the confident, noninvasive diagnosis and categorization of atrial septal defects. Two-dimensional echocardiographic contrast and Doppler examinations complement the technique and enhance diagnostic accuracy.