Quantitative assessment of contractile reserve of systemic right ventricle in post-Senning children: Incorporating speckle-tracking strain and dobutamine stress echocardiography.

INTRODUCTION

The systemic load on the right ventricle (RV) after Senning atrial switch leads to ventricular dysfunction. Quantitative assessment of RV contractile reserve is mandatory to anticipate the need for anti-fibrotic treatment. We aimed to quantitatively assess RV contractile reserve in Senning children by estimating speckle-based global longitudinal strain (GLS) during dobutamine stress echocardiography (DSE).

METHODS

This prospective study compared thirty-one post-Senning children (group I) and thirty controls (group II). In post-Senning children, echocardiographic RV systolic function using one-plane ejection fraction (RVEF), RV fractional area change (RVFAC), tricuspid annulus plane systolic excursion (TAPSE), its Z-score, and RVGLS were recorded at rest and peak DSE. Contractile reserve was defined as improvement >5% in RVEF, >2% in GLS, and/or to near normal TAPSE.

RESULTS

RVEF, RVFAC, TAPSE, and TAPSE Z-score were significantly lower in patients than controls [RVEF:40.13 ± 2.93% vs 53.17 ± 3.17% (P < .001*), RVFAC: 21.17 ± 2.37% vs 37.23 ± 2.13% (P < .001*), TAPSE:13.81 ± 1.26 vs 17.45 ± 2.93 mm (P < .001*), TAPSE Z-score: -3.47 ± 0.46 vs -2.09 ± 0.48 (P < .001*)]. Also, RVGLS was significantly impaired in Senning children than controls[ (-11.89 ± 2.31% vs -22.35 ± 6.73% (P < .001*)]. At peak DSE, contractile reserve was not evident as measured by RVEF which increased none significantly to 42.47 ± 2.80% (P = .063). However, RVGLS improved significantly to -15.78 ± 0.93% (P < .001*) and discovered the masked contractile reserve in Senning children. The 19(61.29%) children who showed masked contractile reserve (improvement in RVGLS > 2%) underwent continuation of anti-fibrotic medications.

CONCLUSIONS

Despite systemic RV function in post-Senning children was impaired at rest and during DSE, RVGLS was useful in quantitative assessment of masked contractile thus promoted continuing anti-fibrotic treatment.