Assessment of left ventricular contractile state after anatomic correction of transposition of the great arteries.

Abstract

When compared with intra-atrial baffle repairs for D-transposition of the great arteries (TGA), anatomic correction offers the theoretic advantage that it results in the use of the left ventricle (LV) as the systemic ventricle. Although the long-term success of this procedure depends on the function of the LV, little is known regarding LV postoperative contractile state. The LV end-systolic pressure-dimension and wall stress-shortening (% delta D) relationships, sensitive indexes of contractility, were studied during methoxamine-induced increases in afterload in eight patients with TGA and intact ventricular septa and in four patients with TGA and associated lesions. The patients with TGA and intact ventricular septa underwent pulmonary artery banding when they were between the ages 0.1 and 1.1 years (mean 0.4) to prepare the LV for anatomic correction. Age at repair ranged from 0.3 to 1.8 years (mean 1.0) and that at study from 1.7 to 6.7 years (mean 3.3). The interval from correction to study was 0.4 to 4.8 years (mean 2.3). End-systolic pressure was estimated from a calibrated suprasternal notch tracing. End-systolic dimension, wall thickness, and % delta D were determined by M mode and two-dimensional echocardiography, and end-systolic wall stress was then calculated. Results were compared with previously reported normal values. The pressure-dimension and wall stress-% delta D relationships were normal in 10 of 12 TGA patients.(ABSTRACT TRUNCATED AT 250 WORDS)