Twenty-nine patients (12 with d-transposition of the great arteries and 17 with congenitally corrected transposition of the great arteries) who underwent LV training with PAB placement were evaluated retrospectively. LV ejection fraction and global and regional longitudinal strain and strain rate were measured before and 7 ¡À 5 days after PAB placement and subsequent anatomic repair.
PAB placement caused reductions in the mean LV ejection fraction from 76.1 ¡À 10.2 % to 66.7 ¡À 7.8 % (P < .001), in mean global strain from ?17.7 ¡À 9 % to ?13.3 ¡À 7.5 % (P?= .01), and in mean lateral wall strain from ?23.3 ¡À 12.8 % to ?17.5 ¡À 10.3 % (P?= .01). After anatomic repair (a median of 21 months after PAB placement; range, 0.5-104 months), mean LV ejection fraction decreased further from 63.3 ¡À 8.6 % to 52.4 ¡À 14.9 % (P < .05). Mean global strain declined from ?17.6 % ¡À 4.4 to ?12.6 ¡À 4 % (P?= .01), and mean lateral wall strain decreased from ?18.2 ¡À 11.4 % to ?12.6 ¡À 5.3 % (P?= .04).
In patients with ventriculoarterial discordance undergoing PAB placement for LV training and anatomic repair, the morphologic left ventricle demonstrated decremental systolic function and global longitudinal deformation acutely. Frequent functional assessment is warranted to understand long-term myocardial mechanics in these patients.