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.