Key Points
- To evaluate the relationship between hemodynamic energy dissipation in the total cavopulmonary connection (TCPC) and exercise capacity in single-ventricle patients.
- Assessed 30 consecutive Fontan patients undergoing standard metabolic exercise testing and cardiac magnetic resonance (CMR) imaging.
- Acquired patient-specific vascular anatomies and flow velocities at rest and immediately following supine lower-limb cycle ergometer exercise via phase-encoded velocity mapping CMR.
- Computed TCPC power loss using computational fluid dynamics simulations based on in vivo anatomy and flow measurements.
- Indexed power loss during exercise negatively correlated with minute oxygen consumption (r = -0.60, p < 0.0005) and total work (r = -0.62, p < 0.0005) at the anaerobic threshold.
- Indexed power loss increased in an exponential relationship relative to rising cardiac output during physical exertion (y = 0.9671x^3.0263, p < 0.0001).
Structured PICO
PPopulation30 consecutive single-ventricle patients after Fontan with total cavopulmonary connection (TCPC) undergoing standard metabolic exercise testing.
OOutcomeCorrelation between indexed power loss at exercise and minute oxygen consumption and work at anaerobic thresholdsurrogate
Aerobic exercise tolerance in Fontan patients is negatively correlated with TCPC power loss, suggesting energy dissipation limits exercise capacity.