Background: The left ventricle in patients with hypoplastic left heart syndrome may influence right ventricular function and outcome. We aimed to investigate differences in right ventricular deformation and intraventricular dyssynchrony between hypoplastic left heart syndrome patients with different anatomical subtypes and left ventricle sizes after Fontan surgery using two-dimensional speckle tracking.
Patients and methods: We examined 29 hypoplastic left heart syndrome patients aged 5.4 plus or minus 2.8 years after Fontan surgery and compared 15 patients with mitral and aortic atresia with the remaining 14 patients with other anatomic subtypes. We used two-dimensional speckle tracking to measure the global and regional systolic longitudinal strain and strain rate as well as intraventricular dyssynchrony.
Results: Global strain (-19.5, 2.8% versus -17.4, 3.9%) and global strain rate (-1.0, 0.2 per second versus -0.9, 0.3 per second) were not different between groups. The mitral and aortic atresia group had higher strain in the basal septal (-13.0, 5.0% versus -3.9, 9.3%, p = 0.003) and mid-septal (-19.4, 4.7% versus -13.2, 6.5%, p = 0.009) segments, and higher strain rates in the mid-septal segment (-1.14, 0.3 per second versus -0.95, 0.4 per second, p = 0.047), smaller left ventricle area (0.18, 0.41 square centimetre versus 2.83, 2.07 square centimetre, p = 0.0001), and shorter wall-to-wall delay (38, 29 milliseconds versus 81, 57 milliseconds, p = 0.02).
Conclusion: Significant differences in regional deformation and intraventricular dyssynchrony exist between the mitral and aortic atresia subtype with small left ventricles and the other anatomic subtypes with larger left ventricles after Fontan surgery.