Respiratory system in children with Fontan circulation from the pulmonologist’s point of view

Abstract

Fontan procedure is a surgical operation for patients who were born with one working heart ventricle that involves complete separation of the pulmonary and the systemic circulation systems, which significantly improves their quality of life and becomes the preferred method of palliative surgery for congenital heart defects with univentricular hemodynamics. Despite all of its advantages this procedure is associated with a number of limitations dictated by the unique type of blood circulation. The uniqueness of Fontan hemodynamics lies in the fact that it is based on passive (non-pulsatile) pulmonary blood flow, which ensures gas exchange and preload of a single (systemic) ventricle. Pulmonary blood flow is determined by central venous pressure (CVP) and pulmonary vascular resistance. Therefore, systemic ventricular preload and cardiac output depend on well-running lung function coupled with low values of pulmonary vascular resistance. Various pulmonary anatomical or pathophysiological changes may compromise the optimal Fontan circulation. This bibliographical review represents currently known data on cardiopulmonary interactions within Fontan circulation, the causes for and the variants of the pulmonary dysfunction.