Peak Oxygen Consumption (V̇O 2peak ) Recovery Delay in a Pediatric Fontan Population.

Purpose: The purpose of this study is to identify predictors and correlates of VO2RD in youth with Fontan.

Methods: Cardiopulmonary exercise test data was used from a single center, cross-sectional study of children and adolescents (age, 8-21 yr) with Fontan physiology. The VO2RD was determined using time (s) to <90% of V̇O 2peak and categorized as "low" (≤10 s) or "high" (≥10 s). t Tests and χ 2 analysis were used to compare continuous and categorical variables, respectively.

Results: The analysis sample included 30 adolescents with Fontan physiology (age, 14.2 ± 2.4 yr; 67% male) with either right ventricular (RV) dominant (40%) or co/left ventricular (Co/LV) dominant (60%) systemic ventricular morphology. There were no differences in V̇O 2peak between the high and low VO2RD groups (high = 1.3 ± 0.4 L·min -1 ; low = 1.3 ± 0.3 L·min -1 ; P = 0.97). VO2RD in participants with RV dominance was significantly greater than in patients with Co/LV dominance (RV = 23.8 ± 15.8 s; Co/LV = 11.8 ± 16.1 s; P = 0.03).

Conclusions: V̇O 2peak was not correlated with VO2RD when analyzed as high/low VO2RD groups. However, morphology of the systemic single ventricle (RV vs Co/LV) may be related to rate of recovery in V̇O 2 after a peak cardiopulmonary exercise test.