Immediate cardiovascular response to Fontan fenestration test occlusion: insights from interventional cardiac MR and biomechanical modeling

Motivation: In patient with Fontan circulation fluid dynamic efficiency in total cavopulmonary connection (TCPC) may be compromised affecting overall cardiovascular health. Goal(s): We aimed to quantify the relationships between blood energy loss in TCPC (i.e. given by indexed power loss, iPL) and Fontan conduit narrowing, myocardial contractility, and fenestration flow pre- and post-FFTO. Approach: iPL in the TCPC region was calculated from iCMR data, and a biomechanical model was used to derive patient-specific myocardial contractility. Results: Pre-FFTO, increased iLP was associated with increased contractility, and increased fenestration flow, and decreased conduit area. Post-FFTO, increased iPL was associated with decreased contractility. Impact: In patients with Fontan circulation the relationship between fluid dynamic efficiency in total cavopulmonary connection and myocardial mechanics can be investigated by interventional CMR and biomechanical modeling. The proposed framework allows to investigate immediate cardiovascular response to fenestration test occlusion.