Exercise Testing After the Fontan Operation

Exercise capacity and impact of exercise training in patients after a Fontan procedure: A review

“…The main studies supporting these observations are reviewed, with a focus on the physiological adaptation and limitation of the exercise performance as well as the benefits of exercise training in patients after a Fontan procedure. (14,15). Nevertheless, the long-term impact of this procedure on exercise tolerance is equivocal.…”

“…This leads to a limited increase in pulmonary blood flow in response to exercise, a reduced left ventricle filling and a smaller stroke volume, resulting in a reduced increase in Q. The blood pressure response to exercise seems normal and adapted to the workload (14,15). However, a higher diastolic blood pressure response during exercise has also been reported (11), and may be explained by the absence of a systemic-to-pulmonary shunt (11) and/or may be linked to the abnormal reflex signals coming from the ergoreceptors (15).…”

“…This is demonstrated by an elevated ventilatory equivalent for oxygen at rest and at (41) No change in submaximal heart rate Driscoll et al (41) Higher or no change in blood Driscoll et al (10) (10) ventilation maximal exercise (14). Following the surgical procedure, the ventilatory equivalent for oxygen may be corrected at rest but stays slightly elevated at maximal exercise (15,37).…”

“…Following the surgical procedure, the ventilatory equivalent for oxygen may be corrected at rest but stays slightly elevated at maximal exercise (15,37). This is the consequence of an increased physiological dead space to tidal volume ratio resulting from ventilation or perfusion mismatch and a persistent right-to-left shunt, hypoxic stimulation of ventilation and/or the need to maintain acid-base homeostasis by eliminating carbon dioxide from a reduced blood volume (10,14,39,41). Furthermore, a significant increment of the ventilatory equivalent for carbon dioxide has also been reported (15,37,(42)(43)(44), suggesting excessive ventilation in patients after a Fontan procedure compared with healthy individuals.…”

“…This reduction may be the consequence of an intrapulmonary right-to-left shunt that may become more important over time following the procedure, coronary sinus blood return to the pulmonary venous atrium, an intracardiac rightto-left shunt, a significant physiological dead space and/or a ventilation/perfusion mismatch with an abnormal pulmonary blood flow distribution (10,14,17,37,47). The lower arterial blood saturation may also be the result of a flow increment in the lungs' superior lobes with increased pulmonary vascular resistance (47).…”