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Updated: Jul 1, 2025
Author Spotlight: Effect of Left Atrial Ligation on Avian Embryonic Hearts and HLHS Implications
Published on: June 16, 2023
Labyrinthine cor triatriatum sinister in fetal hypoplastic left heart syndrome is associated with poor outcomes
Amna Qasim1,2, Tam T Doan1, Betul Yilmaz Furtun1
1The Lillie Frank Abercrombie Section of Cardiology, Texas Children's Hospital, Department of Pediatrics, Baylor College of Medicine, Houston, Texas, USA.
Insights
Hypoplastic left heart syndrome (HLHS) fetuses with labyrinthine-cor (L-cor) have significantly increased mortality. Early recognition of L-cor in HLHS is crucial for accurate prognostication and planning interventions.
Area of Science:
- Pediatric Cardiology
- Fetal Cardiology
- Congenital Heart Disease
Background:
- Hypoplastic left heart syndrome (HLHS) is a severe congenital heart defect.
- A subset of HLHS fetuses present with a complex cor-triatriatum sinister, termed labyrinthine-cor (L-cor).
- The prognostic implications of L-cor in HLHS remain unclear.
Purpose of the Study:
- To determine the prevalence of L-cor in fetuses with HLHS.
- To investigate the association between L-cor and mortality in HLHS fetuses.
- To evaluate the impact of L-cor on survival outcomes.
Main Methods:
- Retrospective cohort study of 156 HLHS fetuses (2010-2020).
- L-cor identified in a subset of HLHS cases.
- Pulmonary vein flow (VTI ratio) used to define restrictive atrial shunting (RAS) and severe RAS.
- Kaplan-Meier survival analysis for transplant-free survival at 1 year.
Main Results:
- 11% (7.7%) of HLHS fetuses had L-cor, with 72.7% also having RAS.
- HLHS fetuses with L-cor and RAS showed lower survival to 28 days (62.5% vs 87%) and 1 year (25% vs 69.6%) compared to those without L-cor.
- Severe RAS with L-cor was associated with significantly lower survival rates (p=0.020).
Conclusions:
- Labyrinthine-cor (L-cor) is an important finding in fetal HLHS.
- The presence of L-cor is associated with increased mortality in HLHS.
- Identifying L-cor aids in prognostication and planning of fetal interventions.
Objectives:
A subset of hypoplastic-left-heart-syndrome (HLHS) fetuses have a complex cor-triatriatum sinister that we named "labyrinthine-cor (L-cor)". We sought to determine the prevalence of L-cor in HLHS fetuses and hypothesized that it is associated with increased mortality.
Methods:
This single-center retrospective cohort study included all HLHS fetuses from January 2010-December 2020. Fetuses with other hypoplastic-left-heart variants, inadequate images, lack of follow-up and fetal atrial-septal interventions were excluded. RAS was defined as the ratio of pulmonary-vein forward-to-reverse velocity-time-integral (VTI) ≤ 5 and severe-RAS defined as VTI-ratio <3. Kaplan-Meier survival-analysis was performed for the primary outcome of transplant-free survival for 62 weeks after gestational-age of 30 weeks (∼1 year).
Results:
Of the 156 consecutive fetuses with HLHS, 11 (7.7%) had L-cor and 8/11 (72.7%) of these had RAS. When compared to HLHS-RAS without L-cor, fetuses with HLHS-RAS and L-cor were less likely to survive to 28 days (87% vs. 62.5%, p = 0.017) and to 1 year (69.6% vs. 25%, p = 0.029). When comparing by survival analysis, fetuses with severe-RAS with L-cor had lower survival compared severe-RAS without L-cor (p = 0.020).
Conclusion:
L-cor in fetal HLHS is associated with increased mortality. Recognition of this finding is important for prognostication and atrial-septal-intervention planning.
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