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

In 13 patients with d-transposition of the great arteries with intact ventricular septum (simple d-TGA) computer-assisted analysis of the echocardiographic pressure-dimension relations were performed. Despite lowered left ventricular peak wall stress, the cycle efficiency was reduced, indicating incoordinate contraction and relaxation. The cycle efficiency showed strong correlation with the arterial oxygen saturation, but not with the peak wall stress.