Objectives: The aim of the present study was to characterize the contraction pattern of the systemic right ventricle (RV).
Background: Reduced longitudinal function of the systemic RV compared with the normal RV has been interpreted as ventricular dysfunction. However, longitudinal shortening represents only one aspect of myocardial deformation, and changes in contraction in other dimensions have not previously been described.
Methods: Fourteen Senning-operated patients age 18.4 +/- 0.9 years (mean +/- SD) with transposition of the great arteries were studied. We compared the contraction pattern of the systemic RV with findings in the RV and left ventricle (LV) of normal subjects (n = 14) using tissue Doppler imaging and magnetic resonance imaging.
Results: In the systemic RV free wall, circumferential strain exceeded longitudinal strain (-23.3 +/- 3.4% vs. -15.0 +/- 3.0%, p < 0.001) as was also the case in the normal LV (-25.7 +/- 3.1% vs. -16.5 +/- 1.7%, p < 0.001), opposite from the findings in the normal RV (-15.8 +/- 1.3% vs. -30.7 +/- 3.3%, p < 0.001). Strain in the interventricular septum did not differ from normal. Ventricular torsion was essentially absent in the systemic RV (0.3 +/- 1.8 degrees ), in contrast to a torsion of 16.7 +/- 4.8 degrees in the normal LV (p < 0.001).
Conclusions: In the systemic RV as in the normal LV, there was predominant circumferential over longitudinal free wall shortening, opposite from findings in the normal RV. This may represent an adaptive response to the systemic load. Noticeably, however, the systemic RV did not display torsion as found in the normal LV.