Echocardiography of the intra-atrial baffle in dextro-transposition of the great vessels.

Twelve patients with dextro-transposition of the great vessels (age eight months to four years) were studied by echocardiography following Mustard's procedure. Nine of them had also been studied preoperatively. Postoperatively all patients demonstrated structural echoes in the atrial cavity behind the pulmonary root. In ten, the motion pattern generally resembled that of a stenotic atrioventricular valve iwth a sharp anterior movement followed by flattening in diastole and rapid posterior excursion in systole. The maximum amplitude of motion ranged from 4 to 9 mm (average 6.6 mm). In the remaining two cases, the anterior diastolic movement was attenuated. Similar moving, linear echoes with larger amplitudes of motion (10-14 mm) were observed behind the tricuspid valve in four patients while poorly moving, multiple or thick conglomerate echoes (2-11 mm wide) were detected in seven cases. Echocardiographic contrast studies performed by injecting indocyanine green via catheters placed on either side of the intra-atrial baffle identified it as the source of these echoes. Following operation, coarse diastolic undulations of the mitral valve (ten cases) and the tricuspid valve (nine cases) were noted. Also, fine flutter of both atrioventricular valves, not present before, appeared after operation in three patients. These findings may be related to the altered pathway of blood flow and turbulence resulting from the insertion of the baffle in the atria. Echocardiography appears useful in delineating the character and movement pattern of the intra-atrial baffle and this may have potential in evaluating its long-term functional status.