Cardiopulmonary Exercise Testing Characterizes Silent Cardiovascular Abnormalities in Asymptomatic Pediatric Cancer Survivors

Abstract

BackgroundLate-onset cardiovascular complications are of serious concerns for even asymptomatic pediatric cancer survivors (PCS). We investigated whether cardiopulmonary exercise testing (CPET) can delineate the underlying pathophysiology of preclinical cardiovascular abnormalities in PCS. MethodsWe examined CPET data via cycle ergometer in asymptomatic PCS with normal echocardiogram and age-matched controls. Peak and submaximal parameters were analyzed. ResultsFifty-three PCS and 60 controls were studied. Peak oxygen consumption (VO2), peak work rate (WR), and ventilatory anaerobic threshold (VAT) were signi cantly lower in PCS than controls (1.86 ± 0.53 vs. 2.23 ± 0.61 L/min, 125 ± 45 vs. 154 ± 46 watt, and 1.20 ± 0.35 vs. 1.42 ± 0.43 L/min, respectively; all p < 0.01), whereas peak heart rate (HR) and ventilatory e ciency (a slope of minute ventilation over CO2 production or DVE/DVCO2) were comparable. Peak respiratory quotient (RQ) was signi cantly higher in PCS (p = 0.0006). Stroke volume (SV) reserve was decreased in PCS, indicated by simultaneous higher dependency on HR (higher ΔHR/ΔWR) and lower peak oxygen pulse (OP) at the peak exercise. Twelve PCS with high peak RQ (≥ 1.3) revealed lower pVO2 and VAT than the rest of PCS despite higher ventilatory e ciency (lower DVE/DVCO2), suggesting fundamental de ciency in oxygen utilization in some PCS. ConclusionsPoor exercise performance in PCS is mainly attributed to limited stroke volume reserve, but the underlying pathophysiology is multi-factorial. Combined assessment of peak and submaximal CPET parameters provided critical information in delineating underlying exercise physiology of PCS.

Left Ventricle Size Correlates with Peak Exercise Capacity in Pediatric Cancer Survivors Exposed to Anthracycline Chemotherapy

“…This stroke volume response to peak exercise correlated with LV cavity size (see Supplemental Materials). A similar submaximal stroke volume response has been previously demonstrated, when assessing ΔHR/Δ work rate as a surrogate for stroke volume [ 23 ]. During peak exercise, a normal individual can be expected to augment stroke volume by up to 25%.…”

Comprehensive Analysis of Cardiopulmonary Exercise Testing Characterizes Age-Related Exercise Performance in Growing Children and Adolescents

“…In this study, we used "two-dimensional CPET analysis," unique and simple CPET interpretation methods, to aid understanding of exercise physiology [15,16,34]. In addition to interpreting each isolated CPET value, we assessed one CPET value in context with other parameters to understand the difference of general trends of two groups.…”

Age-Related Exercise Performance in Growing Children and Adolescents Assessed by Peak and Submaximal Cardiopulmonary Exercise Testing Parameters

“…With comparison with regression lines, we aimed to characterize how age-related growth and functional maturation in uenced exercise performance. Correlations between weight (kg) and pVO2 (L/min), DHR/DWR and DVO2/DHR, VAT (L/min) and pVO2 (L/min), and pVE (L/min) and pVO2 (L/min) indicate group trends of skeletal muscle effects, stroke volume reserve, exercise endurance beyond anaerobic threshold (AT), and ventilatory e ciency of oxygen uptake, respectively [15][16][17].…”

“…In this study, we used "two-dimensional CPET analysis", unique and simple CPET interpretation methods, to aid understanding of exercise physiology [15,16,35]. In addition to interpreting each isolated CPET value, we assessed one CPET value in context with other parameters to understand the difference of general trends of the two groups.…”