Congenital: Fontan
Diastolic inflow is associated with inefficient ventricular flow dynamics in Fontan patients

Read at the 100th Annual Meeting of The American Association for Thoracic Surgery: A Virtual Learning Experience, May 22-23, 2020.
https://doi.org/10.1016/j.jtcvs.2021.06.064Get rights and content
Under an Elsevier user license
open archive

Abstract

Objective

This study used cardiac magnetic resonance imaging to evaluate flow characteristics and ventricular hemodynamics for children with single right (hypoplastic left heart syndrome) and single left (hypoplastic right heart syndrome) systemic ventricle anatomy after Fontan palliation compared with normal biventricular controls.

Methods

Twenty children with single ventricle anatomy (hypoplastic left heart syndrome, n = 10; hypoplastic right heart syndrome, n = 10) underwent standardized 4-dimensional flow cardiac magnetic resonance and were compared with age-matched controls (n = 10). End-diastolic volume was partitioned into 4 defined components of variable kinetic energy (direct flow, retained inflow, delayed ejection, and residual volume) and compared between groups. Further, volumetric and functional parameters as defined by cardiac magnetic resonance were evaluated.

Results

Children with hypoplastic left heart syndrome had significantly increased indexed end-diastolic and end-systolic volumes compared with both hypoplastic right heart syndrome and control groups. Flow component analysis demonstrated diastolic inefficiency in both hypoplastic left heart syndrome and hypoplastic right heart syndrome groups compared with controls as defined by decreased direct flow and increased residual volumes. Decreased direct flow correlated with decreased ejection fraction and increased end-diastolic and end-systolic volume indices. Increased residual volume correlated with decreased ejection fraction and increased end-systolic volume index.

Conclusions

Fontan-palliated patients with single ventricle physiology (hypoplastic left heart syndrome and hypoplastic right heart syndrome) demonstrate altered and inefficient flow patterns in the systemic ventricle as defined by 4-dimensional flow cardiac magnetic resonance compared with normal biventricular controls. Decreased direct flow and increased residual volume indicate that diastolic ventricular dysfunction is prevalent after Fontan palliation. This study provides a foundation for future predictive modeling and cardiac magnetic resonance flow diagnostic studies in this high-risk patient population.

Graphical abstract

Flow component analysis by 4D-flow CMR demonstrates inefficient diastolic inflow partitioning in patients with HLHS and HRHS compared with biventricular control patients as defined by decreased direct flow and increased residual volume.

  1. Download : Download high-res image (346KB)
  2. Download : Download full-size image

Key Words

4D-flow cardiac MRI
hypoplastic left heart syndrome
hypoplastic right heart syndrome
post-Fontan physiology
single ventricle congenital heart disease

Abbreviations and Acronyms

CMR
cardiac magnetic resonance
4D
4-dimensional
HLHS
hypoplastic left heart syndrome
HRHS
hypoplastic right heart syndrome
MRI
magnetic resonance imaging

Cited by (0)

Funding source: Rady Family and Jayden DeLuca Foundations.

The Institutional Review Board of the University of Colorado School of Medicine approved the study protocol and publication of data (Institutional Review Board protocol no. 19-1420; date of approval: June 20, 2019). The patients provided informed written consent for the publication of the study data.