What are the determinants of cardiac output in patients with a Fontan circulation?
This review provides a conceptual model emphasizing that pulmonary vascular resistance, rather than unlimited preload, is a primary determinant of cardiac output in the Fontan circulation.
In a Fontan circuit the mechanisms involved in control of cardiac output at rest and during exercise differ significantly from normal. The classical model presumes an unlimited preload which is not available in the Fontan circuit. This review critically analyses the role of contractility, heart rate, and afterload and highlights the importance of pulmonary vascular resistance (PVR) in determining adequate preload and, therefore, cardiac output in these patients. A conceptual model of the determinants of cardiac output in Fontan patients is presented.
Gewillig et al. (Tue,) studied this question.