D-Transposition of the Great Arteries after Arterial Switch Operation: Usefulness of 3D-Echocardiography for Left Ventricle Function Evaluation

Objective: The objective of this study was to assess left ventricle (LV) function and remodeling by three-dimensional echocardiography (3DE) in patients who underwent arterial switch procedure (ASO) for transposition of great arteries (TGA) in long-term follow-up. Methods and Results: We studied 54 asymptomatic patients (39 male) who have undergone single-stage ASO for TGA, aged 13.7 ± 4.7 years, with a normal LV ejection fraction (EF), compared to healthy peers. We evaluated LV volume and function in asymptomatic patients with normal ejection fraction by 3DE. All patients had normal EF, measured by modified Simpson’s method (mean 60.9 ± 3.5%) and by 3D method (mean 62.3 ± 3.8%). No statistically significant differences were documented between 2D and 3D measures of age-related LV volumes. Comparison of 3D volumes with reference ones was performed only in pediatric patients (<18 years old). In this subgroup (n = 42) 3D volumes were significantly higher than reference values from the age of 9 years (End-diastolic volume: 9–12 years 79.61 ± 20.29 ml vs.53.52 ± 13.94 ml, p < 0.001; 13–17 years 107.30 ± 23.28 ml vs. 81.78 ± 26.44 ml, p = 0.0038). Conclusions: Children and young adults late after ASO demonstrate normal ejection fraction, but present subclinical signs of ventricular and myocardial remodeling, such as increased LV dimensions, when using 3D echocardiography. Our findings support the usefulness of 3DE to detect LV remodeling precociously.