In one of the most severe congenital heart defects, hypoplastic left heart syndrome (HLHS), the left ventricle is underdeveloped and the prognosis is worse than in most other heart defects. The underdevelopment can occur gradually during fetal growth caused by a narrowing of the aortic valve. At some international centers, such fetuses are treated with a balloon dilation of the narrowed valve, but there is no scientifically sound evidence that this treatment is effective.
The aim of this study is: 1/ to evaluate whether balloon dilation during the fetal period of a narrowed aortic valve can reduce the risk of the left ventricle becoming underdeveloped and the baby being born with a so-called univentricular heart (HLHS); 2/ to investigate whether such treatment improves the prognosis for this group of children with a very complex and severe heart defect and 3/ to also describe side effects and risks in fetuses and mothers of the fetal procedure.
Aortic valve stenosis with antegrade flow through the valve
Predominantly left-to-right shunt at the atrial level
Predominantly retrograde flow in the aortic arch between the first two brachiocephalic vessels
Qualitatively depressed left ventricular function
Any associated cardiac defect except persistent left superior vena cava and coarctation of the aorta
Any significant (i.e. that might influence outcome) extracardiac anomaly and/or known chromosomal aberration. Also, if such a condition is present at inclusion but diagnosed only after birth the case will be retrospectively excluded.
Queen Silvia Children's Hospital, Gothenburg, Sweden
Lead sponsor
Swedish Heart Lung Foundation
Collaborator
Sahlgrenska University Hospital
Collaborator