Caval flow reflects Fontan hemodynamics: quantification by magnetic resonance imaging

Area of Science:

• Cardiology
• Pediatric Cardiology
• Medical Imaging

Background:

• Fontan circulation failure presents challenges due to unclear predictors and onset.
• Investigating systemic venous flow return is crucial for understanding Fontan patient condition.

Purpose of the Study:

• To explore correlations between systemic venous flow dynamics and the clinical status of Fontan patients.
• To identify potential early indicators of suboptimal Fontan hemodynamics.

Main Methods:

• Phase contrast magnetic resonance imaging (MRI) was used to measure flow in the superior and inferior vena cava (SVC, IVC) in 61 Fontan patients.
• Key metrics included venous cardiac index (vCI) and SVC flow ratio.
• Flow data were analyzed in relation to patient hemodynamics and age.

Main Results:

• Patients with suboptimal hemodynamics had significantly lower inferior vena cava (IVC) flow and a higher SVC flow ratio.
• Total venous cardiac index (vCI) showed a decrease correlated with older patient age.
• These findings suggest altered venous flow patterns in Fontan patients with poorer clinical condition.

Conclusions:

• Changes in systemic venous flow return are associated with suboptimal Fontan hemodynamics.
• These alterations appear to progress with patient age and long-term follow-up.
• MRI-based flow measurements may enable early monitoring of Fontan patients before clinical deterioration.