Influence of age on wall thickness, cavity dimensions and myocardial contractility of the left ventricle in simple transposition of the great arteries.

Abstract

This study was carried out to establish a reference table of echocardiographic values for the left ventricle of simple d-transposition of the great arteries (d-TGA) and to determine at what age left ventricular dimensions in these patients become different from those of a normal population. Fifty-three patients with d-TGA and normal pulmonary pressure and 395 normal children ages 1 day to 10 years were studied by M-mode echocardiography. Results show that in d-TGA, left ventricular systolic and diastolic internal diameters are normal at birth. After 1 month, however, both diameters were below normal and despite a progressive increase with age, the mean values were always below normal. The mean posterior wall thickness of patients with d-TGA was also normal at birth but did not increase with age (2.3 mm in diastole and 4.3 mm in systole) and became significantly thinner than normal at 10 months of age in diastole and 7 months in systole. Septal thickness of patients with d-TGA did not differ from that of the control group. The shortening fraction and mean velocity of circumferential fiber shortening were significantly greater in d-TGA at all ages. Left ventricular measurements related to age are presented and should be of help in interpreting M-mode echocardiograms of patients with d-TGA.

Incoordinate contraction and relaxation in d-transposition of the great arteries with intact ventricular septum — Analyses of pressure-dimension relations

“…4, Table 1) (p ~ 0.001). This is in agreement with the finding, that the posterior wall thickness remains nearly constant throughout childhood in patients with simple d-TGA and low left ventricular pressure, thus reflecting a low peak wall stress (7,10,16). Surprisingly the cycle efficiency was also significantly reduced in simple d-TGA, despite the lowered peak meridional wall stress (p -< 0.001) (Fig.…”

“…In d-transposition of the great arteries with intact ventricular septum (simple d-TGA) the left ventricular muscle mass does not increase normally after birth (7,8,10,14,16). If anatomic correction in simple d-transposition is not performed in the first weeks of life, a left ventricle adapted to low pressures has to take over systemic load, so that a preoperative banding of the pulmonary artery is necessary for the "'training" of the left ventricle (21)(22)(23).…”

Clinical guidelines for the management of patients with transposition of the great arteries with intact ventricular septum

“…Left ventricular 'preparedness' for an ASO is commonly judged on measurable parameters (e.g. left ventricular geometry, wall thickness and function on echocardiogram) and on additional evidence of pressure and volume loading related to the size of the duct and an ASD [91,100,105,[107][108][109][110]. The ventricular septum is forged by unequal ventricular pressures and progressively shifts towards the pulmonary ventricle, assuming a banana-shaped appearance on an echocardiogram [111,112].…”

Criteria for two-staged arterial switch operation for simple transposition of great arteries.

“…The study included 35 patients who underwent the switch operation after banding and anastomosis; two died shortly after surgery, and one died of tachycardia 31 days after the operation. The left-to-right ventricular pressure ratio was above 0.83 in all surviving patients, 0.68 and 0.63 in the two operative deaths, and 0.84 in the other death.…”