Dr. Patricia Longmuir is lead author on a paper titled, “Enhanced Physiology for Submaximal Exercise in Children after the Fontan Procedure,” that was published recently in Medicine & Science in Sports & Exercise. Citations information is below.
Banks L, McCrindle BW, Russell JL, Longmuir PE. Enhanced Physiology for Submaximal Exercise in Children after the Fontan Procedure. Med Sci Sports Exerc. 2012 Nov 27. [Epub ahead of print]
ABSTRACT: Purpose: After the Fontan procedure, children exhibit reduced peak exercise capacity; yet, their sub-maximal exercise response remains unclear. This study sought to determine the relationship between sub-maximal and peak exercise capacity, and physical activity in Fontan patients. Methods: This cross-sectional study recruited 50 Fontan patients (59% males) with a median age of 9 years (range: 6-12). The median age at Fontan procedure was 2.9 years (range: 1.6-9.1). Study assessments included medical history, exercise testing, and accelerometry. Results: Significantly lower sub-maximal oxygen consumption (VO2) and heart rate (HR) in response to a standardized workload than published values for healthy children, (mean±SD) of -1.72±5.24 (p<0.001) and -1.45±1.98 (p<0.001), respectively, suggest enhanced sub-maximal work efficiency in this group of patients after Fontan. Higher sub-maximal VO2 z-score was associated with higher sub-maximal HR z-Score (p=0.02) and lower body mass index z-score (p=0.01). Higher peakVO2 was associated with higher sub-maximal VO2 z-score (p<0.01), male sex (p=0.03), higher RER (p=0.02), lower sub-maximal HR z-score (p<0.01), and higher chronotropic responsiveness (p<0.0001). Exercise test duration z-score was associated with lower sub-maximal HR z-score (p=0.02) and higher chronotropic responsiveness (p=0.02). Conclusions: Fontan patients exhibit a lower sub-maximal VO2 and HR responsiveness at a given workload than healthy controls during standardized exercise testing; Thus, they may be better adapted to perform sub-maximal exercise. While peak exercise capacity is limited, Fontan patients are able to perform sub-maximal physical activities at the same level as their healthy peers.
