Effect of respiration on cardiac filling at rest and during exercise in Fontan patients: A clinical and computational modeling study

Authors

Alexander Van De Bruaene, University Hospitals Leuven, Belgium
Guido Claessen, University Hospitals Leuven, Belgium
Andre La Gerche, University of Melbourne
Ethan Kung, Clemson UniversityFollow
Alison Marsden, University of California - San Diego
Pieter De Meester, University Hospitals Leuven, Belgium
Sarah Devroe, University Hospitals Leuven, Belgium
Jan Bogaert, University Hospitals Leuven, Belgium
Piet Claus, University Hospitals Leuven, Belgium
Hein Heidbuchel, Heart Center Hasselt, Belgium
Werner Budts, University Hospitals Leuven, Belgium
Marc Gewillig, University Hospitals Leuven, Belgium

Document Type

Article

Publication Date

8-2015

Publication Title

IJC Heart & Vasculature

Publisher

Elsevier

DOI

10.1016/j.ijcha.2015.08.002

Abstract

Due to the absence of a sub-pulmonary ventricle, the Fontan circulation is sensitive to respiration-induced changes in intrathoracic pressure. However, the importance of a ‘respiratory pump’ in creating forward flow remains controversial. We aimed at evaluating the effect of respiration on ventricular filling during exercise using clinical data and computational modeling predictions. Ten Fontan patients (6 male, 20 ± 4 years) underwent ungated cardiac magnetic resonance (CMR) imaging at rest and during supine bicycle exercise to evaluate systemic ventricular volumes (end-diastolic volume index (EDVi), end-systolic volume index (ESVi) and stroke volume index (SVi)) during normal respiration and a Valsalva maneuver. Respiratory-dependent SV was calculated. Clinical results were compared to predictions made by a closed-loop lumped-parameter (LPN) computational model of Fontan circulation. Inspiration resulted in increased EDVi (98 ± 16 to 103 ± 15 mL; P = 0.001), SVi (55 ± 9 to 59 ± 9 mL; P = 0.001) and cardiac index (3.9 ± 0.7 to 4.2 ± 0.8 L/min; P = 0.002), whereas ESVi (P = 0.096) remained unchanged. The effect of inspiration on EDVi (mean effect + 6 ± 1 mL; P < 0.0001) and SVi (+ 4 ± 1 mL; P < 0.0001) was maintained during exercise. Respiratory-dependent SVi tended to increase during exercise (3 ± 2% to 5 ± 3%; P = 0.084). Valsalva resulted in decreased EDVi (P = 0.001), ESVi (P = 0.003) and SVi (P = 0.005). Computational modeling indicated higher EDV and SV at end-inspiration and expiration, showing a phased time delay between peak caval vein flow and peak SV. In Fontan patients, inspiration resulted in increased ventricular filling at rest and during exercise. Results were confirmed using a computational model indicating a phased time delay between peak SV and peak caval vein flow.

Comments

Copyright © 2015 The Authors. Published by Elsevier Ireland Ltd.

Under a Creative Commons license

Recommended Citation

Bruaene, A.V., Claessen, G., Gerche, A.L., Kung, E., Marsden, A., Meester, P.D., Devroe, S., Bogaert, J., Claus, P., Heidbuchel, H., Budts, W., & Gewillig, M. (2015). Effect of respiration on cardiac filling at rest and during exercise in Fontan patients: A clinical and computational modeling study. International journal of cardiology. Heart & vasculature.