SUMMARY
Single ventricle (SV) malformations are among the most complex congenital heart defects (CHDs),
affecting about 2 per 1000 births in the United States. Common palliation for SV patients is the staged
Fontan procedure. This procedure culminates in a total cavopulmonary connection (TCPC), designed to
connect systemic and pulmonary circulations in series. Immediate post-procedural outcomes are usually
favorable. However, various long-term complications afflict the Fontan population, and many are
associated with Fontan obstruction. Previous studies define Fontan obstruction as vessel narrowing or
elevated energetics in the TCPC; however, they often overlook the performance of the patient’s ventricle,
the core issue of SV malformations. Consequently, only weak correlations were observed between
formerly defined Fontan obstruction and long-term complications in Fontan patients. Therefore, this
proposed work will focus on two prevalent Fontan complications, diminished quality of life (QoL) and
reduced exercise performance, to (1) identify an innovative definition of Fontan obstruction that integrates
TCPC geometry and/or TCPC hemodynamics with ventricular performance and (2) to quantify the level
of newly defined Fontan obstruction for optimal QoL and exercise performance in Fontan patients. Two
specific aims will accomplish this project: (1) Quantify Fontan obstruction as a marker of quality of life.
The working hypothesis is that an obstruction metric that integrates TCPC geometry and/or TCPC
hemodynamics with ventricular performance at rest will provide a better quantification of Fontan
obstruction and serve as a marker of QoL. (2) Quantify Fontan obstruction as a marker of exercise
performance. This aim hypothesizes that an obstruction metric that integrates TCPC geometry and/or
TCPC hemodynamics with ventricular performance (under resting conditions, exercise conditions, and/or
the rest-exercise difference) will provide a better quantification of Fontan obstruction and serve as a
marker of exercise capacity. Both aims will use cutting-edge, validated computational fluid dynamics and
fluid-structure interaction modeling to obtain TCPC hemodynamics and ventricular performance,
respectively. The proposed work is of great impact due to its goals of better quantifying Fontan obstruction
to improve QoL and exercise performance for Fontan patients. Furthermore, this proposal will enhance
undergraduate research and education for the recently established biomedical engineering department
at the University of Massachusetts at Lowell. Undergraduate involvement in this project will allow students
to experience a broad spectrum of state-of-the-art techniques and acquire skills such as medical image
processing and image-based cardiovascular simulations. Additionally, the students will develop a vast
network of partnerships among scientists and clinicians from national and international institutions.
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