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 (%AD) 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 %zXD 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-%AD relationships were normal in 10 of 12 TGA patients. The two patients with abnormal study results had TGA with intact ventricular septa and they underwent correction after 1.5 years of age. There was no relationship between contractile state and either interval from repair to study or age at study. Thus, LV contractility is normal in most patients with TGA who undergo anatomic correction. Circulation 69, No. 1, 106-112, 1984 Patients and methodsOur patient population consisted of 12 children (10 boys and two girls) who had undergone anatomic correction for TGA (table 1). Only patients in close geographic proximity to the study site in Harefield, England were evaluated. Before surgery eight children had TGA with intact interventricular septa (IVSs) and four had additional defects (large ventricular septal defects in three, and aortopulmonary window in one). All of the children with TGA/IVSs underwent two-stage repair with initial pulmonary artery banding performed when they were from 0.1 to 1.1 years of age (mean 0.4). The patients' ages at repair ranged from 0.3 to 1.8 years (mean 1.0), and their ages at postoperative study ranged from 1.7 to 6.7 years (mean 3.3); the interval between definitive repair and study ranged from 0.4 to 4.8 years (mean 2.3). The technique used for anatomic correc- Subjects under 6 years of age were given light sedation with oral trimeprazine (2.5 mg/kg) followed in 1 hr by an intramuscular injection of papaveretum (0.33 mg/kg) and scopolamine (0.0067 mg/kg). All patients were premedicated with intravenous atropine (0.01 mg/kg) to abolish reflex cardiac slowing. Each subject underwent simultaneous recordings of syst...

Rapid two-stage arterial switch operation. Evaluation of left ventricular systolic mechanics late after an acute pressure overload stimulus in infancy.

“…LV function has been shown to be better preserved when a primary ASO was performed compared with a two-stage approach when the ASO was delayed beyond infancy." 5 Specific reasons for this difference are unclear, but the duration of the LV preparatory period has been proposed as a possible mechanism.135-14 Preliminary data from our group15 indicated that LV performance early after a two-stage procedure was preserved when the interval between banding of the pulmonary artery and the ASO was shortened to 1 to 2 weeks compared with prior reports in which preparatory banding was continued for 5 months up to several years.5 However, the late myocar-contractility was observed in the two-stage ASO group. Contractility below the limits of normal was seen in 25% of two-stage ASO compared with 3% of primary ASO; however, symptomatic or progressive LV dysfunction was not observed.…”

Anatomic correction of transposition of the great arteries associated with ventricular septal defect: midterm results in 50 patients.

“…Mean aortic cross-clamp time was 78 min (range 50 to 100 min) and cardioplegia and topical cooling were used. We have previously de 13 Values for these parameters in the patients were compared with those in a control group of 50 normal children of equivalent age and body surface area. The aim of the two-dimensional echocardiographic evaluation was to identify possible left and right anatomic abnormalities, especially aortic bulb dilatations and pulmonary arterial stenosis.…”

Anatomic correction for transposition of the great arteries: First follow-up (38 patients)

“…Originally, in our institution, the mortality rate of the arterial switch was high . The cardiac catheter studies showed normal function of both ventricles, as described before in patients after an arterial switch procedure [3,4] . All of these 12 patients had complicated TGA, because, in that period, a Senning procedure was still first choice in simple TGA .…”