M-mode echocardiographic assessment of D-transposition of the great arteries and associated defects.

Abstract

M-mode echocardiographic, hemodynamic, and angiographic correlations are presented for 97 patients with d-transposition of the great arteries. Forty-one patients were studied before and 73 patients after the Mustard operation; 17 patients were studied sequentially before and after the Mustard operation. The echocardiographic diagnosis of d-transposition could be made with high accuracy by using two criteria: (1) opening of the posterior semilunar valve earlier than the anterior semilunar valve, and (2) location of the anterior semilunar valve to the right of the posterior semilunar valve with transducer angulation toward the right shoulder. In the pre-Mustard group the presence of associated lesions such as patent ductus arteriosus and ventricular septal defect was suggested by an elevated left ventricular end-diastolic/right ventricular end-diastolic dimension ratio (>1.2). In the post-Mustard group, after correction of shunting lesions, this ratio was similar to that in patients with intact ventricular septum. In pre-Mustard patients the anatomically fixed type of left ventricular outflow tract stenosis was suggested by a left ventricular outflow tract/pulmonary artery ratio of less than 0.5. This ratio was 0.52±0.1 in those in whom resection of the anatomic stenosis and Mustard operation were performed. Right ventricular function could be assessed by the pre-ejection period/right ventricular ejection time ratio; a ratio of greater than 0.5 was associated with angiographically determined ejection fraction of 0.5 or less.