Use of the heart rate monitor to modulate physical activity in adolescents with congenital aortic stenosis: an innovative approach

Vascular and autonomic function in preschool-aged children with congenital heart disease

OBJECTIVE

To compare indices of vascular health and heart rate variability in preschool-aged children with repaired congenital heart disease (CHD) including tetralogy of Fallot (n = 6) and coarctation of the aorta (n = 6).

DESIGN

  A cross-sectional study design was used. All measures were noninvasive and collected over a single testing session under the supervision of a parent/guardian.

SETTING

  Data collection took place in a quiet, temperature-controlled room (23°± 1°C) with the participant in a supine position.

PATIENTS

  Twelve (six females, six males) preschool-aged children with repaired CHD (CHD: 4 ± 1 years) and 12 age- and gender-matched healthy controls (CON: 5 ± 1 years) participated in the study.

OUTCOME MEASURES

  Supine, resting measures of heart rate variability (time, frequency, and nonlinear domains), whole-body pulse wave velocity (ventricular depolarization to dorsalis pedis artery), brachial blood pressures, and carotid artery distensibility, lumen diameter, intima-media thickness, and wall/lumen ratio were collected in both groups.

RESULTS

  The groups were similar in age, height, and weight; however, CON had significantly higher body mass index values (CON: 16.9 ± 2.2, CHD: 15.1 ± 1.0, P < .05) and body mass index percentiles (CON: 69 ± 27%tile, CHD: 36 ± 24%tile, P < .01) compared to CHD. No group differences were found for resting brachial blood pressures, whole-body pulse wave velocity, heart rate variability, and carotid artery distensibility, lumen diameter, and intima-media thickness (P > .05). Carotid artery pulse pressures (CHD: 38 ± 6 mm Hg, CON: 31 ± 6 mm Hg, P < .05) and wall/lumen ratios (CHD: 0.091 ± 0.007, CON: 0.085 ± 0.006, P < .01) were significantly higher in the CHD group.

CONCLUSIONS

  These results may indicate that preschool-aged children with repaired CHD display early signs of vascular remodeling, but not autonomic or vascular dysfunction. The effects of larger wall/lumen ratios on cardiovascular disease risk require further investigation.

Physical activity levels in children and adolescents are reduced after the Fontan procedure, independent of exercise capacity, and are associated with lower perceived general health

OBJECTIVES

To determine physical activity levels in paediatric patients who underwent the Fontan procedure, and their relationship to functional status and exercise capacity.

STUDY DESIGN

We studied 147 patients (ages 7-18 years) at a median of 8.1 years after Fontan, as part of the Pediatric Heart Network cross-sectional study of Fontan survivors. Assessment included medical history, self-reported physical activity, parent-completed Child Health Questionnaire (CHQ), cardiopulmonary exercise testing and physical activity level measured by accelerometry (MTI Actigraph).

RESULTS

Measured time spent in moderate and vigorous activity was markedly below normal at all ages, particularly in females, and was not significantly related to self-reported activity levels, or to maximum Vo2, Vo2 at anaerobic threshold or maximum work rate on exercise testing. Lower measured activity levels were significantly related to lower perceived general health but not to self-esteem, physical functioning, social impact of physical limitations or overall physical or psychosocial health summary scores. Reduced exercise capacity was more strongly related than measured activity levels to lower scores in general health, self-esteem and physical functioning.

CONCLUSIONS

Physical activity levels are reduced after Fontan, independent of exercise capacity, and are associated with lower perceived general health but not other aspects of functional status.