Functional pulmonary atresia in neonatal Marfan's syndrome: successful treatment with inhaled nitric oxide.

Functional pulmonary atresia is characterized by a structurally normal pulmonary valve not opening during right ventricular ejection. We report this rare condition in a premature newborn of a twin pregnancy, in which fetal echocardiography findings were consistent with critical pulmonary stenosis. After birth, features of neonatal Marfan's syndrome were noted. Echocardiography showed a morphologically normal but immobile pulmonary valve with continuous regurgitation. Right ventricular pressure was subsystemic. In this case, initial treatment with nitric oxide, followed by pharmacological duct closure, was successful. Differentiating between anatomic and functional pulmonary valve atresia may be difficult. The echocardiographic criteria are discussed.

Transcatheter reconstruction of obliterated superior vena cava with additional obliteration of right internal jugular and subclavian vein.

We describe the successful reconstruction of a completely obliterated superior vena cava, despite additional obliteration of right internal jugular and subclavian vein, using an end-to-side approach to connect to the innominate and left internal jugular vein. We also document long-term patency.

Consistency of children's hemodynamic responses to laboratory stressors.

Hemodynamic responses to three standard laboratory stressors (i.e., postural change, video game, forehead cold) were evaluated in 341 children (170 males) who had a mean age of 11.2 +/- 2.6 years. Inter-task consistency was evaluated for five physiological parameters for all stressor pairings. Evidence of consistency in systolic and diastolic blood pressure, heart rate, cardiac output, and total peripheral resistance responses to all three stressors was observed. The highest and most consistent correlations across stressors were observed for cardiac output and total peripheral resistance responses. The need for clarification in the categorization of laboratory stressors used to measure reactivity is discussed.

The effect of adiposity on children's left ventricular mass and geometry and haemodynamic responses to stress.

This study evaluated the relationship between adiposity, left ventricular mass and geometry, and haemodynamic parameters at rest and during laboratory stressors in a sample of 69 normotensive children with positive family histories of essential hypertension. Children were classified as overweight if they were above the 85th percentile of weight-for-height for their age and gender compared to national normative data. Nineteen children (7 whites, 12 blacks) were classified as overweight and the remaining 50 (26 whites, 24 blacks) were not overweight. Overweight children were found to have higher resting systolic and diastolic blood pressures, heart rates (HR), cardiac output (CO) and stroke volumes (SV), and lower resting total peripheral resistance than the non-overweight children. No differences were noted in haemodynamic reactivity to the stressors. Echocardiographic findings indicated that the overweight children had greater left ventricular mass indexed by height2.7, interventricular septal thickness and left ventricular end diastolic diameter (LVEDD) compared to non-overweight children. These findings are the first to indicate that the higher resting pressures of overweight normotensive children are a reflection of increased normotensive children are a reflection of increased preload (i.e. greater HR, SV, CO, LVEDD). These findings point out the early deleterious effects of obesity on the cardiovascular system in the young and highlight the need for effective obesity prevention and intervention programmes.

Pressor reactivity, ethnicity, and 24-hour ambulatory monitoring in children from hypertensive families.

We assessed blood pressure responses of a multiethnic (Black and White) sample of 120 children of hypertensive families to orthostasis, video game, forehead cold, and dynamic exercise, and monitored the children's ambulatory pressure 24 hours later. Thirteen children were studied twice (1-year stability). The Black children exhibited higher 24-hour ambulatory systolic and diastolic pressures than the White children. Regardless of ethnicity, peak and mean systolic pressures during each task were generally positively correlated with mean systolic pressure while the children were awake and asleep. Associations between diastolic pressor responses and ambulatory measurements were somewhat dependent upon ethnicity and task. Relatively few reactivity-ambulatory correlations were significant, using pressor reactivity change scores. The children who participated twice exhibited significant 1-year stability for most ambulatory and pressor measurements. Children's pressor responses to laboratory tasks may generalize to the natural environment.

1-year stability and prediction of cardiovascular functioning at rest and during laboratory stressors in youth with family histories of essential hypertension.

Blood pressure (BP). heart rate, cardiac index, and total peripheral resistance index were measured at rest and in response to postural change, forehead cold stimulation, and a video game challenge in a sample of 128 White and 155 African-American normotensive youth with family histories of essential hypertension (EH). These measurements were readministered 1 year later (12.5 +/- 3.2 months). Moderate temporal stability was observed for all resting and absolute stress responses. Reliability estimates for reactivity change scores were lower, although some were within acceptable ranges. African-American youth exhibited greater BP and peripheral resistance index reactivity to forehead cold on both evaluations. After controlling for various anthropometric and demographic parameters and the pertinent previous year's resting cardiovascular (CV) parameter, mean video game systolic blood pressure (SBP) responses were predictive of resting SBP whereas absolute forehead cold and video game diastolic responses predicted resting diastolic blood pressure (DBP) 1 year later. Mean video game DBP responses were also predictive of resting peripheral resistance index after controlling for significant demographic and anthropometric measures. CV reactivity is discussed with regard to possible value in prediction of changes in resting BP and cardiac structure prior lo establishment of EH.

Determinants of left ventricular mass in normotensive children.

Left ventricular hypertrophy has been shown to be an independent predictor of cardiovascular morbidity and mortality. Few studies have examined the determinants of left ventricular mass (LVM) in normotensive children. Eight-four healthy children, blacks and whites, girls and boys, between 6 and 18 years of age, all with positive family histories of essential hypertension, participated in the study. Demographic and anthropometric characteristics, physical activity, and hemodynamic responses at rest and in response to the stress of forehead cold stimulation and a challenging video game were related to M-mode echocardiographic determined LVM indexed by two indices of body habitus. Hierarchical stepwise multiple regression analysis indicated that the significant independent correlates of LVM per body surface area were gender (boys were greater), baseline systolic blood pressure and heart rate, a physical activity index (sweat episodes per week) and peak systolic blood pressure responses to the forehead cold stressor (final model r2 = 0.49). For LVM/height2.7 significant independent correlates were adiposity index (weight z score--height z score), gender (boys were greater), age, resting systolic pressure, and systemic vascular resistance reactivity to forehead cold stimulation (final model r2 = 0.42). These findings with normotensive children corroborate other findings that have typically involved hypertensive children, indicating that resting heart rate and systolic pressure, gender, and adiposity are early determinants of LVM indices in children. In addition, the current findings indicate that hemodynamic responses to stress also appear to play a role in the early development of LVM.(ABSTRACT TRUNCATED AT 250 WORDS)

Ethnicity, gender, family history of myocardial infarction, and hemodynamic responses to laboratory stressors in children.

Relationship among ethnicity, gender, grandparents' histories of early myocardial infarction, and hemodynamic responses to forehead cold and treadmill exercise were examined in 87 6-to-8-year-olds (57 White, 30 Black). Boys had greater increases in systemic vascular resistance and decreases in cardiac index to forehead cold. Girls had greater increases and quicker recovery in heart rate to dynamic exercise. Blacks had greater increases and slower recovery in diastolic pressure to exercise and forehead cold. Blacks showed greater increases and slower recovery in systemic vascular resistance to forehead cold. Positive-family-history children had greater increases in diastolic pressure and systemic vascular resistance to forehead cold and greater diastolic pressure increases to exercise. Positive-family-history Blacks had greater increases in systolic pressure to exercise and slower recovery than all other groups.

Anemia in the adolescent athlete.

Anemia is a common disorder among adolescents regardless of level of physical activity. The major cause of anemia in adolescents is nutritional iron deficiency. Iron metabolism may be altered in some athletes training and competing in endurance sports. The dilutional "sports anemia" that can occur in the more elite adolescent athlete may be an adaptation to aerobic conditioning. Screening for anemia in adolescent athletes is warranted because anemia may contribute to morbidity and diminished exercise performance. Current concepts and controversies regarding anemia in adolescent athletes are addressed, and application of this information to preparticipation physical examinations is examined.