Regression of marked myocardial sinusoids associated with hypoplastic left heart syndrome during staged Fontan approach.

The anatomic subtype of mitral stenosis, aortic atresia, and myocardial sinusoids is reported to be associated with increased mortality for staged repair for hypoplastic left heart syndrome. We herein report a very rare case of this subtype of hypoplastic left heart syndrome presenting with marked myocardial sinusoids in the left ventricle, which nearly disappeared after successful Fontan completion. Our successful experience suggests marked myocardial sinusoids per se are not a risk factor for surgical palliation in hypoplastic left heart syndrome.