No abstract

Advanced quantitative assessment of SV function post-Fontan can be consistently and efficiently performed real time during clinically indicated echocardiograms with excellent reliability.

Background The Single Ventricle Reconstruction (SVR) trial demonstrated a transplant-free survival advantage at 12 month follow up for patients with right-ventricle-pulmonary-artery shunt (RVPAS) at Norwood procedure versus modified Blalock-Taussig shunt (MBTS) but similar survival and decreased global right ventricular (RV) function on longer term follow-up. The impact of the required ventriculotomy for the RVPAS remains unknown. We compared echo-derived RV deformation indices after stage 2 procedure in survivors with single RV anomalies enrolled in the SVR trial. Methods Global and regional RV systolic longitudinal and circumferential strain and strain rate, ejection fraction, and short axis % fractional area change were all derived by speckle tracking echocardiography from protocol echocardiograms performed at 14.3±1.2 months. Student’s t-test or Wilcoxon rank sum test was used to compare groups. Results The cohort included 275 subjects (129 MBTS and 146 RVPAS). Longitudinal deformation could be quantified in 214 (78%) subjects and circumferential measures in 182 (66%) subjects. RV ejection fraction and % fractional area change did not differ between groups. There were no significant differences between groups for global or regional longitudinal deformation. Circumferential indices showed abnormalities in deformation in the RVPAS group with decreased global circumferential strain (p=0.05), strain rate (p=0.09) and anterior regional strain rate (p=0.07) that approached statistical significance. Conclusion RV myocardial deformation at 14 months, after stage 2 procedure, is not significantly altered by the type of initial shunt placed. However, abnormal trends were appreciated in circumferential deformation for the RVPAS group in the area of ventriculotomy that may represent early myocardial dysfunction. These data provide a basis for longer-term RV deformation assessment in survivors after Norwood procedure.

Background Heart size and function in children with single right ventricle (RV) anomalies may be influenced by shunt type at the Norwood procedure. We sought to identify shunt-related differences during early childhood after staged surgical palliations using echocardiography. Methods We compared echocardiographic indices of RV, neoaortic, and tricuspid valve size and function at 14 months, pre-Fontan, and 6 years in 241 subjects randomized to a Norwood procedure using either the modified Blalock-Taussig shunt or RV-to-pulmonary-artery shunt. Results At 6 years, the shunt groups did not differ significantly in any measure except for increased indexed neoaortic area in the modified Blalock-Taussig shunt. RV ejection fraction improved between pre-Fontan and 6 years in the RV-to-pulmonary artery shunt group but was stable in the modified Blalock-Taussig shunt group. For the entire cohort, RV diastolic and systolic size and functional indices were improved at 6 years compared with earlier measurements, and indexed tricuspid and neoaortic annular area decreased from 14 months to 6 years. The prevalence of ≥moderate tricuspid and neoaortic regurgitation was uncommon and did not vary by group or time period. Diminished RV ejection fraction at the 14-month study was predictive of late death/transplant; the hazard of late death/transplant when RV ejection fraction was <40% was tripled (hazard ratio, 3.18; 95% CI, 1.41–7.17). Conclusions By 6 years after staged palliation, shunt type has not impacted RV size and function, and RV and valvar size and function show beneficial remodeling. Poor RV systolic function at 14 months predicts worse late survival independent of the initial shunt type. Clinical Trial Registration URL: https://www.clinicaltrials.gov . Unique identifier: NCT00115934.