The Syndrome of Left Isomerism

Abstract

Prenatal diagnosis of left isomerism is feasible, with high accuracy. Important diagnostic pointers are viscerocardiac heterotaxy, complex cardiac malformations, heart block, and interruption of the inferior vena cava. The mortality in fetuses and neonates is high in the presence of heart block and hydrops, whereas the cardiac defects influence the long-term outcome.

Perinatal and Infant Outcomes of Prenatal Diagnosis of Heterotaxy Syndrome (Asplenia and Polysplenia)

“…In the PSP group, the survival with a biventricular circulation was significantly higher than previously reported. 3,10 Although the survival for both ASP and PSP of continued pregnancies in our study was slightly better than previously reported (44% vs 12% to 21% for ASP 12,15 and 79% vs 39% to 61% in PSP 1,12,13,15 ), the prognosis for patients with HS is still dismal, especially for those with ASP. The improvement in our survival rate can be explained by a most recent era analyzed and in the case of PSP by the inclusion of a high proportion of normal hearts.…”

“…1,12–15 The present study, which examines the largest reported cohort of fetuses with HS to date, sheds light on the perinatal and short-term outcomes and expands on prognostic factors provided by other studies. The information in this study will assist practitioners in the prenatal counseling of patients and in the perinatal and neonatal management.…”

“…Of note, bradyarrhythmia was a strong predictor of fetal death but was not a risk factor for postnatal death in the entire cohort of HS, diverging from previous reports where nearly all patients with bradyarrhythmia died during the first year of life. 1,3,16,18,22 …”

“…1–4 Moreover, in those patients who require palliative surgery for their complex congenital heart disease, many will later succumb to the burden of the Fontan circulation. 5–7 Pediatric studies on HS have demonstrated cardiac risk factors that determine outcomes.…”

“…3,4,8–11 However, there are limited data on perinatal outcomes after prenatal diagnosis of HS and risk factors for death. 1,12–15 Studying the fetal cohort is important as an increasing percentage of congenital heart defects are diagnosed prenatally. Furthermore, although prenatal diagnosis of HS has not been shown to affect postnatal survival, 12,14,15 it likely affects pregnancy outcome and allows for informative counseling and, in the perinatal period, alerts the medical team to institute appropriate medical care in a timely fashion.…”