Abstract 11506: Total Cavopulmonary Connection Geometry and Hemodynamics: Implications on Patient Exercise Performance
Background: Single ventricle (SV) patients with a total cavopulmonary connection (TCPC) have limited exercise capacity. Elevated TCPC energy loss is hypothesized to decrease SV efficiency and impede exercise performance. Optimizing TCPC surgical design holds the promise of improving exercise capacity. This study aimed to investigate the correlations between TCPC geometry features, TCPC exercise energy loss, and patient exercise performance.
Methods: Forty seven TCPC patients (age=19±6years) who completed standard exercise stress test and exercise cardiac magnetic resonance (CMR) were included. TCPC anatomies were reconstructed from CMR images and geometric features analyzed. Vessel flows at ventilatory anaerobic threshold (VAT) were obtained from phase contrast CMR images acquired immediately following lower leg exercise using a cycle ergometer. Numerical simulations were performed to quantify TCPC power loss during exercise (iPLVAT). Regressions between TCPC geometry features, iPLVAT, and minute oxygen consumption at VAT (VO2) were investigated.
Results: Significant correlations are shown in Figure 1. VO2 was negatively correlated with age. In adolescents (12-18yrs), VO2 was negative correlated with iPLVAT and positively correlated with normalized minimum TCPC diameter. For adults (>18yrs), these correlations were not significant. Instead, VO2 was positively correlated with normalized total systemic venous return, and negatively correlated with age.
Conclusions: In adolescent Fontan patients, lower normalized minimum TCPC diameter and elevated power loss may contribute to worse exercise performance. Alternatively, exercise performance in adult patients worsens with increasing age and reduced systemic venous return. Understanding these relationships will allow clinicians to identify Fontan patients at risk for diminished exercise tolerance and may allow for interventions to maximize patient exercise performance.
Author Disclosures: E. Tang: None. R.H. Khiabani: None. K.K. Whitehead: None. M. Restrepo: None. L. Mirabella: None. J. Bethel: None. S.M. Paridon: None. B.S. Marino: None. M.A. Fogel: None. A.P. Yoganathan: None.
- © 2014 by American Heart Association, Inc.