Childhood cardiac function after severe maternal red cell isoimmunization.

OBJECTIVE: To estimate the long-term effects of anemia on the fetal heart by echocardiography of children who received intrauterine blood transfusions for red cell isoimmunization. METHODS: Surviving children who received intrauterine transfusions during the period from 1992 to 2003 were identified. Children matched for age and sex were chosen for the control group to create a 1:1 case-control study design. A clinical interview, physical examination, and echocardiography assessment (corrected for body surface area) were performed. RESULTS: Twenty-five children were recruited for the case group and matched to 25 healthy children for the control group. Children in the case group had received a median of four intrauterine transfusion procedures (range 1-7), with a median gestation at initial intrauterine transfusion of 28 weeks (range 22-34 weeks). Hydrops was present in 32%. Median initial hemoglobin was 76 g/L (range 25-133 g/L). Median gestation at delivery was 36 weeks (range 29-38 weeks). The median age of children in the case group was 10.1 years (range 3.6-15.8 years) and of those in the control group was 10.5 years (range 3.8-16.4 years; P=.122). There was no difference in body surface area, baseline heart rate, systolic blood pressure, or diastolic blood pressure between children in the case group and those in the control group. Echocardiography demonstrated three main differences: children in the case group had 9% less left atrial area (95% confidence interval [CI] 2-16% less; P=.02), 10% less ventricular mass (95% CI 1-19% less; P=.039), and an average 11 ms less mitral valve atrial duration (95% CI 3-19 ms less; P=.009) than did those in the control group. These results did not alter when adjusted for isoimmunization severity. CONCLUSION: Fetal anemia secondary to red cell isoimmunization is associated with a reduction in left ventricular mass and left atrial area in childhood, although resting ventricular function is maintained. We speculate this may be secondary to the prenatal effects of anemia on cardiomyocyte proliferation and differentiation. LEVEL OF EVIDENCE: III.

Resistance training and diastolic myocardial tissue velocities in obese children.

PURPOSE: The primary purpose of this study was to determine the effects of resistance exercise training on early diastolic myocardial velocities (E') in an obese pediatric population. METHODS: Twenty-three obese adolescents were selected to participate in either a resistance-based training program (RT; n = 13, 12.2 +/- 0.4 yr, body mass index [BMI] = 32.5 +/- 1.9 kg m(-2)) or a nonexercise control intervention (n = 10, 13.6 +/- 0.7 yr, BMI = 30.2 +/- 2.6 kg m(-2)) for 8 wk. All subjects had repeated echocardiographic assessments to determine left ventricular (LV) geometry, early transmitral flow velocity (E), and E'. RESULTS: LV mass and wall thicknesses did not significantly change with training or in controls. RT improved E' (11.9 +/- 0.5 to 13.3 +/- 0.5 cm s(-1), P< 0.01) in the presence of a decrease in E/E' (8.17 +/- 0.39 to 7.06 +/- 0.30 cm s(-1), P < 0.01), a marker of left atrial pressure. No changes were evident in the inactive control subjects. CONCLUSIONS: A supervised 8-wk RT exercise program improved early diastolic tissue velocity in obese children, independent of changes in LV morphology.

Impact of obesity on diastolic function in subjects < or = 16 years of age.

The aim of this study was to investigate the impact of obesity on diastolic function in children and adolescents. Echocardiographic measurements were compared in 28 obese subjects (14 males, 14 females) and 15 age- and gender-matched lean controls (8 males, 7 females). Two-dimensional ultrasound imaging, M-mode imaging, and pulse-wave conventional and tissue Doppler measurements were used to assess cardiac structure and function at rest. No differences were evident between lean and obese subjects in age (13.3 +/- 0.5 vs 12.4 +/- 0.4 years), height (163 +/- 4 vs 159 +/- 2 cm), or systolic blood pressure (119 +/- 3 vs 123 +/- 2 mm Hg). Body mass (54.6 +/- 4.0 vs 85.8 +/- 3.6 kg, p < 0.0001) and body mass index (20.5 +/- 0.7 vs 33.3 +/- 1.0 kg/m2, p < 0.00001) were significantly greater in the obese subjects, whereas measurements of wall thickness (interventricular septal wall 0.86 +/- 0.04 vs 0.89 +/- 0.02 cm, posterior wall 0.83 +/- 0.04 vs 0.91 +/- 0.02 cm) and fractional shortening (38.6 +/- 1.2% vs 38.8 +/- 1.2%) did not significantly differ. The E/E' ratio (6.86 +/- 0.20 vs 8.30 +/- 0.32, p < 0.01), E' (13.93 +/- 0.38 vs 12.29 +/- 0.44 cm/s, p < 0.05), the E'/A' ratio (2.49 +/- 0.17 vs 2.05 +/- 0.09, p < 0.05), and the deceleration time of early transmitral blood flow velocity (125.3 +/- 7.7 vs 154.5 +/- 6.8 ms, p < 0.01) were significantly different between the groups, suggesting reduced diastolic function in the obese subjects. In conclusion, these data suggest that indexes of diastolic function, including tissue Doppler measures, are significantly impaired in obese young subjects.