Prehipertensión en los adolescentes / Prehypertensión in adolescents

Las directrices recientes para la presión arterial (PA)infantil designan la categoría de prehipertensión, definidacomo una PA sistólica o diastólica superior alpercentil 90 e inferior al 95 por edad, sexo y estatura.En la infancia una PA por encima del percentil 95 sedefine como hipertensión (HTA). Dado que en losadolescentes el percentil 90 supera el umbral de los120/80 mmHg, utilizado en adultos para definirpreHTA dicho valor se utiliza como punto de corte inferiorpara la preHTA en los adolescentes. Debido a lavariabilidad inherente de la PA en los jóvenes es necesariorealizar varias mediciones para determinarcon exactitud el estado de la misma. La preHTA en lainfancia, al igual que en la edad adulta, requiere esfuerzosde prevención mediante cambios en el estilode vida respecto a dieta, control de peso y actividadfísica (AU)

Recent guidelines for blood pressure (BP) in childreninclude the category of prehypertension, defined assystolic or diastolic BP between the 90th and 95thpercentiles for the patient’s age, sex, and stature. Duringchildhood, BP above the 95th percentile is consideredhypertension. In adolescents, the 90th percentilesurpasses the threshold of 120/80 mmHg used todefine prehypertension in adults, so this value is usedas the lower cutoff for prehypertension in adolescents.Due to the inherent variability of BP in young people,it is necessary to measure BP several times to determineBP precisely. Prehypertension in childhood, as inadults, requires preventive measures including changesin diet, weight control, and physical activity (AU)

New developments in the treatment of hypoplastic left heart syndrome.

Hypoplastic left heart syndrome (HLHS) was once a uniformly fatal disease, accounting the majority of neonatal deaths due to congenital heart defects. Twenty-five years of advances in the surgical and medical management of this disease have resulted in dramatic improvements in survival for these children. The goal for patients with HLHS should be survival of near 100% with a good quality of life. The advances described in this manuscript detail some of the new techniques used in the surgical and medical management. For infants undergoing staged reconstruction, the Norwood procedure is performed in the newborn period, followed by a hemi-Fontan operation at 6 months of age, and a modified Fontan operation at 1 to 2 years of age. A significant recent modification of the Norwood procedure is the placement of a right ventricle to pulmonary artery (RV-PA) conduit instead of a systemic artery to pulmonary shunt (modified Blalock-Taussig or BT shunt) as the source of pulmonary blood flow. Our recent experience with this modification demonstrated an incremental increase in survival, improved postoperative stability, and decreased inter-stage mortality. At catheterization, significant differences in hemodynamic parameters were present that were consistent with improved coronary blood flow, decreased volume load to the single right ventricle, and improved pulmonary artery growth in those patients with the RV-PA conduit. The 3rd stage in the surgical treatment of HLHS is the modified Fontan operation or cavo-pulmonary anastamosis. A new approach for Fontan completion is the placement of a stent covered with a thin layer of Goretex from the inferior vena cava to the hemi-Fontan baffle. This can be performed in the catheterization laboratory, with a decrease in post-procedure pleural effusions, lower mortality, and a shorter length of stay. The future of treatment for HLHS may eventually involve a single open-heart procedure with initial and final interventions being performed in the catheterization laboratory. Some cardiac centers perform transplantation for management of HLHS. Survival following transplantation has improved as advances in the pre- and post-operative management continue, along with new options for immunosuppression. Treatment for HLHS continues to evolve, as ongoing work has resulted in improved short and long-term survival. The future for children with this disease is encouraging as evidenced by the remarkable achievements made to date and the current worldwide interest and study of HLHS.

What pediatric residents should learn (or what pediatricians should know) about congenital heart disease.

Technologic advances in the care of children with congenital heart disease have resulted in improved care, younger ages at completion of treatment, and improved outcomes. A gap between what the pediatrician needs to do to identify a child with congenital heart disease and the specialized care provided by a cardiologist has developed over time. This has altered physician roles and the training needs for general pediatricians. This article outlines a model for training that emphasizes the skills necessary for pediatricians to identify infants and children early in life with congenital heart disease consistent with advances in diagnosis and management.

Nonadherence is associated with late rejection in pediatric heart transplant recipients.

OBJECTIVES: The objective was to study the impact of nonadherence on late rejection after pediatric heart transplantation. STUDY DESIGN: This was a retrospective cohort study of cardiac transplant recipients surviving >6 months (n = 50). Patients were stratified by episodes of late rejection. End points were defined by cyclosporin A (CSA) level, CSA level variability, and patient admission of nonadherence. RESULTS: In 15 patients there were 49 episodes of late rejection, and 37 (76%) were associated with nonadherence. Of these patients, 7 of 15 died, and 3 of 15 had transplant coronary artery disease. Risk factors for the rejection were single-parent home, non-white, older age, and higher CSA level variability. In 35 nonrejectors there were 4 deaths from sepsis, post-transplant lymphoproliferative disease, renal failure, and encephalomyelitis. CONCLUSION: Late rejection after pediatric heart transplantation is associated with nonadherence, is common during adolescence, and is associated with poor outcome.

Active and passive tobacco exposure.

Both passive and active exposure to tobacco smoke have adverse cardiovascular consequences for children and adolescents. Smoking as a habit begins in mid-adolescence and is perpetuated by the highly addictive nature of nicotine. Smoking has been associated with decreased life expectancy from all causes and early atherogenesis. The physiologic effects of active, and possibly passive smoke exposure include endothelial injury, increased oxidizability of LDL cholesterol, lower HDL cholesterol, impaired exercise performance, and altered oxygen delivery. Physician roles have been limited to research into the harmful nature of tobacco in the past, but new roles in advocacy against tobacco companies and the treatment of nicotine addiction are evolving.

Identification of adolescent tobacco users in a pediatric practice.

CONTEXT: Though prevention of adolescent tobacco use is a major public health goal, there is little information on the ability of pediatricians to identify adolescents experimenting with tobacco and regular tobacco users. OBJECTIVES: To pilot use of a short questionnaire and analysis of urinary cotinine level to identify adolescent smokers in a pediatric practice, and to determine characteristics of tobacco users. SETTING: Suburban pediatric practice. METHOD: Consecutive high school students completed a short questionnaire and urine cotinine assessment. Three groups were defined: smokers (urine cotinine level >100 ng/mL), experimenters (smoked within the last year; urine continine level

Impaired exercise parameters in pediatric heart transplant recipients: comparison of biatrial and bicaval techniques.

The exercise performance of pediatric heart transplant recipients and the effects of bicaval anastomosis were studied in 19 children using a Bruce protocol. Although all children had decreased exercise capacity and heart rates when compared with normals, the bicaval anastomosis patients had similar endurance and peak heart rates as the standard biatrial group.

Successful palliation of Ebstein's malformation on the first day of life following fetal diagnosis.

Severe Ebstein's malformation has a poor prognosis when diagnosed during the neonatal period. Surgical options that have proved successful in older patients have been associated with high mortality and morbidity in neonates. We report here our success with a policy of induction at term and immediate surgical intervention when Ebstein's malformation was diagnosed prenatally.

Reversal of severe late left ventricular failure after pediatric heart transplantation and possible role of plasmapheresis.

Late acute cardiac graft failure carries a high mortality in adults. Vascular mediators and factors other than classic T-cell-mediated rejection may play a role in this process, and aggressive multimodality therapy may improve survival. We report experience with plasmapheresis in treating late severe acute left ventricular dysfunction in a group of pediatric heart transplant recipients. We retrospectively reviewed clinical records, echocardiograms, hemodynamics, coronary angiograms, biopsy specimens, and treatment regimens for 5 patients with 7 episodes of late-onset severe graft failure who recovered. Plasmapheresis was applied in all cases, in addition to methylprednisolone, cyclophosphamide, lympholytic agents, and aggressive supportive care including mechanical ventilation and hemofiltration. All patients presented with acute severe left ventricular dysfunction 1.4 to 7.9 years (mean 3.6) after orthotopic heart transplantation. Mean shortening fraction at presentation was 13 to 23% (mean 16), initial endomyocardial biopsy specimens were grade 0 to 3B, and immunofluorescence studies were negative. Treatment included plasmapheresis, cyclophosphamide, mechanical ventilation, hemofiltration, and inotropes. Clinical recovery was slow, with 4 to 8 weeks until left ventricular function normalized, and 2.2 to 9.4 (mean 4.6) weeks to hospital discharge. At follow-up (50 to 38 months, mean 24), all are alive. Two patients are well, whereas coronary vasculopathy developed in 3. Thus, survival may improve in patients with late graft failure with low biopsy score and plasmapheresis combined with multimodality therapy.

Anthropometric and physiologic correlates of mitral valve prolapse in a biethnic cohort of young adults: the CARDIA study.

OBJECTIVE: To describe the epidemiology of echocardiographic mitral valve prolapse (MVP) and its anthropometric, physiologic, and psychobehavioral correlates with a cross-sectional analysis at 4 urban clinical centers. PATIENTS: A biethnic, community-based sample of 4136 young (aged 23 to 35 years) adult participants in the Coronary Artery Risk Development in Young Adults (CARDIA) study who had echocardiograms during their third examination between 1990 and 1991. MEASUREMENTS: Echocardiographic mitral valve prolapse, Doppler mitral regurgitation, blood pressure, anthropometry, and 4 psychobehavioral scales. RESULTS: Definite echocardiographic MVP prevalence was 0.6% overall and was similar across the 4 ethnicity/sex groups. Most participants (21 of 26, 80%) with definite echocardiographic MVP were unaware of their condition. Relative to persons with normal echocardiograms, those with echocardiographic MVP were taller (174.6 cm vs 171.0 cm, P <.01), leaner (26.7 mm vs 37.4 mm sum of triceps and subscapular skinfolds, P <.01), had lower body mass index (22.0 kg/m(2) vs 26.2 kg/m(2), P <.01), and more often has Doppler mitral regurgitation (34.8% vs 11. 8%, P <.01). Women with echocardiographic MVP had higher ethnicity-adjusted hostility scores (19.9 vs 16.1, P <.05) than women with no MVP. Among 111 (2.7%) of 4136 participants reporting prior physician diagnosis of MVP, only 5 (0.45%) of 111 had definite echocardiographic MVP. CONCLUSIONS: These data document a low prevalence of definite echocardiographic MVP and suggest a constellation of anthropometric, physiologic, and psychobehavioral characteristics in young adults with echocardiographic MVP. Most definite echocardiographic MVP diagnoses were discordant with self-reported MVP status, and false-positive diagnoses of echocardiographic MVP were made more often in women and whites.

Left ventricular growth in selected hypoplastic left ventricles: outcome after repair of coarctation of aorta.

BACKGROUND: Models that predict survival in neonates with left ventricular hypoplasia and critical aortic stenosis may not be applicable to neonates with left ventricular hypoplasia and coarctation. METHODS AND RESULTS: We report 8 infants with severe aortic coarctation and left ventricular hypoplasia. Mean age was 18 days (range 1-48 days), and mean weight was 3.5 kg (range 2.7-4.3 kg). Associated diagnoses included mild aortic stenosis (4), ventricular septal defect (2), and venous anomalies (2). All had coarctation repair as a primary procedure (3 of these had concomitant intracardiac procedures); 7 had subsequent operations. All are alive and well 1.1-6.7 years (mean 3.1 years) after the first surgery. Progressive increases were observed in aortic and mitral diameters, and in left ventricular dimensions, areas, and volumes when the preoperative, earliest postoperative, and most recent echocardiograms were compared. CONCLUSIONS: Despite severe left ventricular hypoplasia, a two-ventricle repair is possible in selected cases. The prognostic criteria for left ventricular hypoplasia in critical aortic stenosis may not be applicable to infant coarctation. Relief of coarctation may result in the growth of the very small left ventricle, especially when the aortic root and mitral diameters are satisfactory.

Perventricular [correction of Periventricular] closure of ventricular septal defects without cardiopulmonary bypass.

BACKGROUND: Minimally invasive techniques are currently in use to close atrial and ventricular septal defects (VSD). Cardiopulmonary bypass (CPB) is instituted via the femoral vessels, which may cause injury to these vessels, especially in younger patients. The objectives of this study were to demonstrate the feasibility of perventricular [corrected] closure of muscular VSD (MVSD) and paramembranous VSD (PVSD) without CPB, using the Amplatz VSD device. METHODS: Five Yucatan pigs with naturally occurring PVSD (3- to 7-mm diameter) and 5 dogs with surgically created MVSD (6- to 14-mm diameter) were subjects of this study. The VSDs were closed intraoperatively with a 7-French delivery sheath inserted through the free wall of the right (n = 5) or left ventricle (n = 5), under epicardial echocardiogram guidance. The animals were followed for 3 months. RESULTS: There was no operative mortality. All MVSD closed after placement of the device. Closure rate of PVSD was 4 of 5 after placement and 3 of 5 after 3 months. One pig developed aortic incompetence at the last follow-up. CONCLUSIONS: Perventricular closure of MVSD and PVSD is feasible. Avoidance of CPB can decrease recovery time, its complications, and trauma to the femoral vessels.

Association of fasting blood sugar level, insulin level, and obesity with left ventricular mass in healthy children and adolescents: The Bogalusa Heart Study.

BACKGROUND: Insulin resistance, often associated with obesity, is hypothesized to be involved in the pathogenesis of essential hypertension and may relate to increased left ventricular mass (LVM). METHODS: We examined correlations between echocardiographic LVM and fasting blood glucose and insulin levels in a cross-section of 216 black and white healthy children and young adults aged 13 to 27 years in Bogalusa, Louisiana. Anthropometric measurements and blood pressure readings were also obtained. RESULTS: Positive bivariate correlation was found between fasting blood glucose level and LVM corrected for growth (LVMC) (LVMC = LVM/Height2.7) with all race/sex groups combined (r = 0.17, P

Beta-blocker treatment of dilated cardiomyopathy with congestive heart failure in children: a multi-institutional experience.

BACKGROUND: Dilated cardiomyopathy is the primary indication for heart transplantation in children beyond infancy. Although beta-blockers improve symptoms, ejection fraction, and survival in adults with congestive heart failure, little is known of their effects in children. METHODS: This study reviews our pediatric experience with the beta-blocker, metoprolol, at 3 institutions. We gave metoprolol to 15 children, age 8.6 +/- 1.3 years (range 2.5 to 15 years), with idiopathic dilated cardiomyopathy (n = 9), anthracycline cardiomyopathy (n = 3), and Duchenne muscular dystrophy cardiomyopathy, postmyocarditis cardiomyopathy, and post-surgical cardiomyopathy (n = 1 each). All had been treated with conventional medications (digoxin, diuretics, and ACE inhibitors) for 22.5 +/- 9 months before starting metoprolol. Metoprolol was started at 0.1 to 0.2 mg/kg/ dose given twice daily and slowly increased over a period of weeks to a dose of 1.1 +/- 0.1 mg/kg/day (range 0.5 to 2.3 mg/kg/day). RESULTS: Between the time point of stabilization on conventional medications and the initiation of metoprolol therapy, there was no significant change in fractional shortening (13.1 +/- 1.2% vs 15.0 +/- 1.2%) or ejection fraction (25.6 +/- 2.1% vs 27.0 +/- 3.4%). However, after metoprolol therapy for 23.2 +/- 7 months, there was a significant increase in fractional shortening(23.3 +/- 2.6%) and ejection fraction (41.1 +/- 4.3%) (p < 0.05). CONCLUSIONS: Metoprolol improves ventricular function in some children with dilated cardiomyopathy and congestive heart failure. Further study is warranted to better define which children may benefit most from beta-blocker therapy and which beta-blockers are most efficacious.

Preventive pediatric cardiology. Tobacco, cholesterol, obesity, and physical activity.

The prevention of coronary artery disease in adults begins in childhood. Public health strategies to lower the use of tobacco, improve nutrition, and increase physical activity are important for all children to lower the cardiovascular risk of the population. Physicians can contribute to public health strategies through office-based health counseling and as advocates for public health strategies both at local and higher levels. Children at high risk for cardiovascular disease can be identified through medical history (i.e., positive family history of coronary disease, history of tobacco use, and physical activity history), routine measurements (i.e., height, weight, and blood pressure), and selective laboratory screening (i.e., lipoprotein measurement). Children at high risk should receive special counseling on diet; physical activity; smoking cessation; and, if indicated, pharmacologic therapy.

Doppler echocardiography with extended transesophageal atrial pacing: predicting the efficacy of permanent atrial pacing in the patient with a small left ventricle and sinus node dysfunction.

A 2100-g neonate underwent a two-ventricular surgical repair of a right ventricle-dominant unbalanced atrioventricular septal defect associated with the heterotaxy syndrome and sinus node dysfunction. Postoperative congestive heart failure persisted despite bradycardia management by temporary ventricular pacing. Spectral Doppler echocardiographic analysis of pulmonary venous inflow and aortic outflow patterns demonstrated significant improvement with transesophageal atrial pacing. Extended transesophageal pacing was performed for two days, resulting in dramatic clinical improvement. This is the first report of extended transesophageal atrial pacing complementing Doppler echocardiography predicting an improved outcome with permanent atrial pacing.

Usefulness of electron beam tomography in adolescents and young adults with heterozygous familial hypercholesterolemia.

BACKGROUND: Because of the success of secondary prevention of coronary events by intense risk factor modification, a more precise measure of atherosclerosis in youth would have great clinical value both in the design of clinical trials for the demonstration of the usefulness of coronary disease prevention early in life and in guiding therapy. Identification of calcium in coronary arteries by electron beam tomography has been associated with severity of atherosclerosis in adults. METHODS AND RESULTS: Twenty-nine youths 11 to 23 years old with familial hypercholesterolemia (average LDL cholesterol, 5.95 mmol/L) underwent electron beam tomography as well as comprehensive risk factor assessment with measurement of total cholesterol, triglycerides, HDL cholesterol, lipoprotein (a), apolipoprotein E phenotype, blood pressure, body mass index, and history of tobacco use. Significant coronary calcium was identified in 7 of 29 subjects. Increased body mass index was significantly associated with the presence of coronary calcium (25.3 versus 20.6 kg/m2, P<0.03). No other risk factors were associated with the presence of coronary calcium. CONCLUSIONS: Coronary calcium, uncommonly identified before the fourth decade, was found in a significant percentage of adolescents and young adults with familial hypercholesterolemia. Overweight may increase the likelihood of coronary calcium being present in individuals already at high risk.

Association of apolipoprotein E phenotype with plasma lipoproteins in African-American and white young adults. The CARDIA Study. Coronary Artery Risk Development in Young Adults.

Apolipoprotein E phenotype (APOE phenotype) has been demonstrated to be a genetic determinant of cardiovascular disease. This atherogenicity may be a reflection of the association of APOE phenotype and plasma lipoprotein concentrations. The Coronary Artery Risk Development in Young Adults (CARDIA) Study affords the opportunity to assess the frequency of apolipoprotein E alleles in population-based samples of African Americans and whites in the United States and to compare the associations of APOE phenotype with lipoprotein and apoprotein concentrations. Data from 3,485 African-American and white men and women between the ages of 25 and 37 years who attended the fourth CARDIA Study examination in 1992-1993 were used in this analysis. African-American men and women had significantly higher frequencies of E2 and E4 phenotype and thus higher frequencies of *epsilon2 and *epsilon4 alleles (p < 0.005). Men and women of both races with APOE4 phenotype generally had higher low density lipoprotein cholesterol, apolipoprotein B, and lipoprotein(a) concentrations and lower high density lipoprotein cholesterol concentration, and individuals with APOE3 phenotype had the lowest triglyceride concentration. Major differences between African Americans and whites were observed in the distribution of APOE phenotypes and *epsilon alleles, but APOE phenotype was associated with similar differences in lipoprotein and apoprotein concentrations in both races. The data suggest that APOE phenotype may be a risk factor for cardiovascular disease in both African Americans and whites because it is associated similarly with an adverse lipoprotein profile.