Premium
Post‐Exercise Oxygen Uptake and Muscle Oxygenation in Pediatric Heart Transplant Recipients
Author(s) -
Kosokowsky Kylee,
Boyes Natasha G,
Lahti Dana S,
Blushke Corey R,
Marciniuk Darcy,
Butcher Scotty J,
Erlandson Marta C,
Wright Kristi D,
Pockett Charissa,
Tomczak Corey R
Publication year - 2019
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.2019.33.1_supplement.lb501
Subject(s) - oxygenation , medicine , cardiology , population , analysis of variance , repeated measures design , incremental exercise , heart rate , exercise physiology , cycle ergometer , physical therapy , anesthesia , blood pressure , mathematics , statistics , environmental health
Pediatric heart transplant recipients (HTR) have reduced exercise tolerance and peak oxygen uptake (VO 2 ) values are 57–73% of age‐predicted norms. Slow post‐exercise VO 2 and muscle oxygenation recovery are related to exercise intolerance. However, despite clear exercise tolerance limitations and post‐exercise fatigue, VO 2 and muscle oxygenation during recovery responses are unknown in this population. Purpose We tested the hypothesis that both post‐exercise VO 2 recovery and muscle oxygenation recovery would be slower after peak exercise in pediatric HTR compared to controls. Methods Five pediatric HTR (mean ± SD age = 10.6 ± 3.0 years) and six healthy controls (age = 11.7 ± 2.7 years) performed cycle ergometry to peak exercise followed by 5 minutes of 20‐W cycle recovery. Pulmonary VO 2 and muscle oxygenation (vastus lateralis tissue oxygenation index, TOI using near infrared spectroscopy) were sampled continuously during exercise and recovery. Data were linearly interpolated to 1‐s intervals, and both VO 2 and TOI data were averaged into 5‐s and 10‐s time bins, respectively. VO 2 recovery data were mono‐exponentially curve‐fitted to yield a recovery time constant (tau). TOI recovery was normalized from 0% (end exercise) to 100% (5 min post‐exercise) and data analyzed at set time points to characterize TOI time course changes (0s, 15s, 30s, 60s, 90s, 120s, 180S, 240s, and 300s). Statistical analyses included independent t ‐tests for VO 2 data and a between‐within (2 × 9, group × time) factorial ANOVA for TOI time course changes. Significance was accepted at p < 0.05. Results Recovery VO 2 tau was significantly slower in pediatric HTR compared to healthy controls (68 ± 17 vs. 47 ± 12 s, respectively; p =0.044). There was a significant group × time interaction for TOI recovery ( p =0.003) where TOI in HTR was significantly lower compared to controls at 15s (8 ± 8 vs. 46 ± 19%; p =0.003), 30s (22 ± 13 vs. 91 ± 31%; p =0.001), and 60s (47 ± 23 vs. 117 ± 36%; p =0.005). TOI was not statistically different between groups by 90s onwards (all p >0.05). Conclusions Post‐exercise VO 2 and TOI recovery are prolonged in pediatric HTR compared to healthy controls. These findings suggest that non‐cardiac factors may contribute to the excessive recovery time following peak exercise in pediatric HTR. This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal .