Introduction: Functional assessment of the systemic right ventricle is often problematic in patients with Dtransposition of the great arteries (D-TGA) due to altered ventricular geometry. The clinical applicability of myocardial deformation imaging by two-dimensional strain (2DS) echocardiography in this setting is still under investigation.
Methods: We evaluated 27 patients with D-TGA (age 30 +/- 6 years, 9 female, 11 with paced rhythm) by standard and 2DS echocardiography; 27 outpatients (age 29 +/- 10 years, 15 female) without structural heart disease served as controls. High-resolution two-dimensional grayscale images were analyzed offline. Global values of peak strain (GS), systolic strain rate (GSRs), and early diastolic strain rate (GSRe) of the systemic ventricle, as well as the systemic ejection fraction (EF), were recorded from apical 4-chamber views. Intraobserver reproducibility was assessed by random-order repeat analysis.
Results: Global indices of myocardial deformation (GS, GSRs, GSRe) in the systemic right ventricle were reliably obtained in all 27 patients with D-TGA, and tracking was optimal in 159/162 segments (>98%). Mean GS in patients with D-TGA was -13.2 +/- 3.8% vs. -20.6 +/- 2.6% in controls, p<0.001; mean GSRs -0.59 +/- 0.16 /s vs. -1.10 +/- 0.19 /s, p<0.001; and mean GSRe 0.68 +/- 0.21 /s vs. 1.34 +/- 0.31 /s, p<0.001. Mean systemic EF by single-plane modified Simpson was 37 +/- 11% in patients with D-TGA vs. 60 +/- 7% in controls, p<0.001. GSRs exhibited the highest discriminative value between D-TGA patients and controls. The mean absolute percent error for GS, GSRs, GSRe, and systemic EF in D-TGA patients was 6.9% (p<0.05 vs. EF), 8.9%, 12.3%, 13.1%, respectively.
Conclusions: Myocardial deformation parameters can be reliably obtained by 2DS echocardiography in patients with D-TGA. Deformation indices of the systemic right ventricle appear to be highly reproducible, and may provide a sensitive means to detect both systolic and diastolic abnormalities in patients with D-TGA.