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Document Details : Title: Can a volume challenge pinpoint the limiting factor in a Fontan circulation? Author(s): W. De Mey , B. Cools , R. Heying , W. Budts , J.J. Louw , D.E. Boshoff , S.C. Brown , M. Gewillig Journal: Acta Cardiologica Volume: 70 Issue: 5 Date: 2015 Pages: 536-542 DOI: 10.2143/AC.70.5.3110514 Abstract : Objective: It is difficult to indicate whether the limitation in a failing Fontan circulation lies within the pulmonary vasculature or the heart. Such differentiation is crucial to direct adequate therapy. This study was set out to determine if a volume challenge could identify the limiting factor. Methods and study population: Thirty-two catheterizations in 28 patients with a Fontan circulation were included. Pressures and oxygen saturations were measured before and after volume challenge (NaCl 0.9%; 15 cc/Kg). The changes in data were grouped based on the location of the major pressure increase. Ventricular function was measured in the resting state. Results: The majority of the patients showed an increase in aortic oxygen saturation, mixed venous oxygen saturation, systolic, pulmonary and systemic venous pressures. The arterio-venous oxygen gradient decreased, suggesting an increase in cardiac output. Different patterns in pressure changes were observed. Most (n = 17) showed a similar increase of ventricular end-diastolic pressure and mean venous pressure (MVP); some (n = 7) showed a lower increase of MVP, suggesting pulmonary reserve and recruitment; others (n = 8) showed a significant higher increase in MVP, suggesting increased pulmonary vascular resistance. All volume challenge was well tolerated. Conclusion: Most patients were preload-responsive. The pressure changes following volume load showed patterns with a potential of differentiating between patients with a major pulmonary or cardiac limiting factor. |
