Fetal echocardiographic predictors of biventricular circulat
A study was conducted to determine which echocardiographic features of hypoplastic left heart complex (HLHC) in the fetal period are predictive of biventricular (BV) circulation and to evaluate the long-term outcome of patients with hypoplastic left heart complex, including rates of mortality, intervention, and development of further cardiac disease.

Echocardiograms of fetuses with hypoplastic left heart complex obtained at 18–26 weeks and 27–36 weeks' gestation were included in the analysis. The primary outcome was successful biventricular circulation (Group 1). Group 2 included patients with single-ventricle palliation, death, or transplant. Univariate analysis was performed on data obtained at 18–26 and 27–36 weeks and multivariate logistic regression was performed on data obtained at 27–36 weeks only.

Of the 51 included cases, 44 achieved successful biventricular circulation (Group 1) and seven did not (Group 2). Right-to-left/bidirectional foramen ovale (FO) flow and a higher mitral valve (MV) annulus Z-score were associated with successful BV circulation on both univariate and multivariate analyses. Bidirectional or left-to-right foramen ovale flow left ventricular length (LVL) Z-score of less than –2.4 and a mitral valve Z-score of less than –4.5 correctly predicted 80% of Group 2 cases. Late follow-up was available for 41 patients. There were two late deaths in Group 2. Thirteen patients in Group 1 required reintervention, 12 developed mitral stenois, and five developed isolated subaortic stenosis.

Biventricular circulation is common in fetuses with hypoplastic left heart complex. Higher mitral valve annulus and left ventricular length Z-scores and right to left direction of foramen ovale flow are important predictors of biventricular circulation. Long-term sequelae in those with biventricular circulation may include mitral and subaortic stenosis.