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1.
Diabetologia ; 55(3): 625-31, 2012 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-22193511

RESUMEN

AIMS/HYPOTHESIS: Increased arterial stiffness is a risk factor for adverse cardiovascular events in adults with obesity-related insulin resistance (IR) or type 2 diabetes mellitus. Adolescents with type 2 diabetes have stiffer vessels. Whether stiffness is increased in obesity/IR in youth is not known. We sought to determine if IR was a determinant of arterial stiffness in youth, independent of obesity and cardiovascular risk factors. METHODS: We measured cardiovascular risk factors, IR, adipocytokines and arterial stiffness (brachial artery distensibility [BrachD], pulse wave velocity [PWV]) and wave reflection (augmentation index [AIx]) in 343 adolescents and young adults without type 2 diabetes (15-28 years old, 47% male, 48% non-white). Individuals <85th percentile of BMI were classified as lean (n = 232). Obese individuals were grouped by HOMA index as not insulin resistant (n = 46) or insulin resistant (n = 65) by the 90th percentile for HOMA for lean. Mean differences were evaluated by ANOVA. Multivariate models evaluated whether HOMA was an independent determinant of arterial stiffness. RESULTS: Risk factors deteriorated from lean to obese to obese/insulin resistant (all p ≤ 0.017). Higher AIx, lower BrachD and higher PWV indicated increased arterial stiffness in obese and obese/insulin-resistant participants. HOMA was not an independent determinant. Age, sex, BMI and BP were the most consistent determinants, with HDL-cholesterol playing a role for BrachD and leptin for PWV (AIx R²= 0.34; BrachD R² = 0.37; PWV R² = 0.40; all p ≤ 0.02). CONCLUSIONS/INTERPRETATION: Although IR is associated with increased arterial stiffness, traditional cardiovascular risk factors, especially obesity and BP, are the major determinants of arterial stiffness in healthy young people.


Asunto(s)
Desarrollo del Adolescente , Arteria Braquial/crecimiento & desarrollo , Resistencia a la Insulina , Rigidez Vascular , Adiposidad , Adolescente , Adulto , Presión Sanguínea , Índice de Masa Corporal , Arteria Braquial/patología , Enfermedades Cardiovasculares/epidemiología , HDL-Colesterol/sangre , Estudios de Cohortes , Estudios Transversales , Femenino , Humanos , Leptina/sangre , Estudios Longitudinales , Masculino , Obesidad/sangre , Obesidad/metabolismo , Obesidad/patología , Ohio/epidemiología , Factores de Riesgo , Adulto Joven
2.
Diabetologia ; 54(4): 722-30, 2011 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-21085926

RESUMEN

AIMS/HYPOTHESIS: We sought to evaluate the effects of obesity and obesity-related type 2 diabetes mellitus on cardiac geometry (remodelling) and systolic and diastolic function in adolescents and young adults. METHODS: Cardiac structure and function were compared by echocardiography in participants who were lean, obese or obese with type 2 diabetes (obese diabetic), in a cross sectional study. Group differences were assessed using ANOVA. Independent determinants of cardiac outcome measures were evaluated with general linear models. RESULTS: Adolescents with obesity and obesity-related type 2 diabetes were found to have abnormal cardiac geometry compared with lean controls (16% and 20% vs <1%, p < 0.05). These two groups also had increased systolic function. Diastolic function decreased from the lean to obese to obese diabetic groups with the lowest diastolic function observed in the obese diabetic group (p < 0.05). Regression analysis showed that group, BMI z score (BMIz), group × BMIz interaction and systolic BP z score (BPz) were significant determinants of cardiac structure, while group, BMIz, systolic BPz, age and fasting glucose were significant determinants of the diastolic function (all p < 0.05). CONCLUSIONS/INTERPRETATION: Adolescents with obesity and obesity-related type 2 diabetes demonstrate changes in cardiac geometry consistent with cardiac remodelling. These two groups also demonstrate decreased diastolic function compared with lean controls, with the greatest decrease observed in those with type 2 diabetes. Adults with diastolic dysfunction are known to be at increased risk of progressing to heart failure. Therefore, our findings suggest that adolescents with obesity-related type 2 diabetes may be at increased risk of progressing to early heart failure compared with their obese and lean counterparts.


Asunto(s)
Diabetes Mellitus Tipo 2/fisiopatología , Obesidad/fisiopatología , Adolescente , Adulto , Presión Sanguínea/fisiología , Índice de Masa Corporal , Niño , Estudios Transversales , Diástole/fisiología , Ecocardiografía , Femenino , Humanos , Masculino , Sístole/fisiología , Circunferencia de la Cintura/fisiología , Adulto Joven
3.
Pediatr Cardiol ; 26(4): 356-60, 2005.
Artículo en Inglés | MEDLINE | ID: mdl-16374684

RESUMEN

The goal of this study was to create nomograms of echocardiographic two-dimensional valve dimensions based on a large group of children without heart disease. Children aged 0-18 years underwent standard echocardiographic evaluation. Referring diagnoses were chest pain, heart murmur, or syncope. Only patients with a structurally normal heart and normal systolic and diastolic function were included. All four valves were measured at their maximal dimensions. A total of 748 children (314 girls and 434 boys) met the inclusion criteria. Mean values and standard deviations were calculated, and z value nomograms based on body surface area were developed. Surprisingly, the boys had larger valve dimensions at all ages. These valve dimension differences were statistically significant for three of four valves even after adjustment for the differences in body sizes. The difference may be due to higher circulating blood volume in boys compared to that in girls. Because the differences are subtle, they reach statistical significance only when evaluated in a large group of subjects. Presented normal value data will be helpful in following cardiology patients and evaluating intervention strategy in patients with valve hypoplasia.


Asunto(s)
Ecocardiografía , Válvulas Cardíacas/diagnóstico por imagen , Adolescente , Niño , Preescolar , Femenino , Humanos , Lactante , Recién Nacido , Masculino , Valores de Referencia , Factores Sexuales
4.
Pediatr Cardiol ; 26(6): 768-71, 2005.
Artículo en Inglés | MEDLINE | ID: mdl-15990951

RESUMEN

Duchenne muscular dystrophy leads to progressive deterioration in skeletal and cardiac muscle function. Steroids prolong ambulation and improve respiratory muscle strength. The authors hypothesized that steroid treatment would stabilize cardiac muscle function. Echocardiograms performed from 1997 to 2004 for 111 subjects 21 years of age or younger with Duchenne muscular dystrophy were restrospectively reviewed. The medical record was reviewed for steroid treatment. Untreated and steroids-treated subjects did not differ in age, height, weight, body mass index, systolic and diastolic blood pressure, or left ventricular mass. The shortening fraction was lower in the untreated group. Of those treated, 29 received prednisone and 19 received deflazacort. There was no difference in the shortening fraction between the two treated subgroups. Treated subjects not receiving steroids still had a normal shortening fraction, which was no different from the shortening fraction of those still receiving treatment. As compared with the treated subjects, the untreated subjects 10 years of age or younger were 4.4 times more likely to have a shortening fraction less than< 28% (p = 0.03), and the untreated subjects older than 10 years were 15.2 times more likely to have a shortening fraction less than< 28% (p < 0.01). This retrospective study suggests that the progressive decline in cardiac function of patients with Duchenne muscular dystrophy can be altered by steroid treatment. The effect appears to be sustained beyond the duration of treatment and independent of steroid type.


Asunto(s)
Glucocorticoides/uso terapéutico , Corazón/efectos de los fármacos , Inmunosupresores/uso terapéutico , Distrofia Muscular de Duchenne/tratamiento farmacológico , Prednisona/uso terapéutico , Pregnenodionas/uso terapéutico , Adolescente , Adulto , Factores de Edad , Niño , Preescolar , Corazón/fisiopatología , Humanos , Distrofia Muscular de Duchenne/fisiopatología , Estudios Retrospectivos , Factores de Tiempo , Función Ventricular Izquierda/efectos de los fármacos
5.
J Matern Fetal Neonatal Med ; 15(1): 44-50, 2004 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-15101611

RESUMEN

OBJECTIVE: To test the hypothesis that, in women with type 1 diabetes, prenatal smoking and caffeine consumption during pregnancy are associated with an increased risk of adverse maternal and perinatal outcomes. METHODS: A secondary analysis of data on pregnant women with type 1 diabetes from an interdisciplinary program of Diabetes in Pregnancy. Women were interviewed monthly, by a trained non-medical member of the research team, using a standardized questionnaire, to ascertain daily smoking habits and caffeine consumption. RESULTS: Smoking and caffeine information were available on 191 pregnancies, 168 progressing beyond 20 weeks of gestation. Early pregnancy smoking (OR 3.3, 95% CI 1.2, 8.7) and caffeine consumption (OR 4.5, 95% CI 1.2, 16.8) were associated with increased risk of spontaneous abortion when controlling for age, years since diagnosis of diabetes, previous spontaneous abortion, nephropathy and retinopathy. Smoking throughout pregnancy was significantly associated with decreased birth weight and prolonged neonatal hospital stay. Smoking throughout pregnancy (OR 0.2, 95% 0.1, 1.0) and caffeine consumption after 20 weeks (OR 0.3, 95% CI 0.1, 1.0) were associated with reduced risk of pre-eclampsia. CONCLUSIONS: Caffeine consumption during early pregnancy, regardless of glycemic control, increases the risk of spontaneous abortion. Smoking throughout pregnancy and caffeine consumption are associated with reduced risk of pre-eclampsia.


Asunto(s)
Cafeína/envenenamiento , Diabetes Mellitus Tipo 1/complicaciones , Embarazo en Diabéticas/complicaciones , Fumar/efectos adversos , Aborto Espontáneo/etiología , Adulto , Peso al Nacer/efectos de los fármacos , Femenino , Humanos , Preeclampsia/etiología , Embarazo , Resultado del Embarazo , Efectos Tardíos de la Exposición Prenatal , Factores de Riesgo , Encuestas y Cuestionarios
6.
J Pediatr ; 138(1): 134-6, 2001 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-11148529

RESUMEN

In order to develop standards for upper lip hair in adolescent girls, 4693 observations in 856 black and white subjects were made over 9 years. Up to 2 years after menarche, 90% of girls had no upper lip hair. More than 2 years after menarche, 48.8% of black girls and 9.0% of white girls had small amounts of upper lip hair. This may be more significant in adolescent girls than in older women.


Asunto(s)
Población Negra/genética , Cabello/fisiología , Hipertricosis/epidemiología , Hipertricosis/genética , Labio , Pubertad/fisiología , Población Blanca/genética , Adolescente , Niño , Femenino , Estudios de Seguimiento , Humanos , Hipertricosis/clasificación , Ohio/epidemiología , Prevalencia , Valores de Referencia , Índice de Severidad de la Enfermedad , Factores de Tiempo
7.
Am J Epidemiol ; 152(12): 1179-84, 2000 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-11130624

RESUMEN

The distribution of body fat has been shown to be an important determinant of cardiovascular disease risk. The purpose of this study was to evaluate which method of evaluating body fat distribution compares most favorably with dual-energy x-ray absorptiometry. The study included 201 children and adolescents aged 7-17 years who were recruited from Cincinnati, Ohio, schools in 1992-1993. The strongest correlate of fat distribution was waist circumference (r = 0.80). Age was a more important determinant of fat distribution than was pubertal maturation. There was a greater relative deposition of central body fat with increasing age. Multiple regression analysis demonstrated that waist circumference was the best simple measure of fat distribution, since it was least affected by gender, race, and overall adiposity. Waist circumference is easy to determine and is a useful measure of fat distribution for children and adolescents.


Asunto(s)
Absorciometría de Fotón , Tejido Adiposo/diagnóstico por imagen , Constitución Corporal , Índice de Masa Corporal , Adolescente , Factores de Edad , Antropometría , Niño , Femenino , Humanos , Masculino , Análisis Multivariante , Ohio , Probabilidad , Valores de Referencia , Análisis de Regresión , Sensibilidad y Especificidad , Factores Sexuales
8.
J Thorac Cardiovasc Surg ; 120(2): 230-7, 2000 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-10917936

RESUMEN

OBJECTIVE: Neutrophil adhesion to endothelium contributes to cardiopulmonary dysfunction after cardiac surgical procedures. Initial neutrophil-endothelial interactions involve selectins, which bind carbohydrate ligands, such as sialyl-Lewis(X). Blockade of selectin-mediated neutrophil interactions with CY1503, a synthetic oligosaccharide analog of sialyl-Lewis(X), could limit neutrophil-mediated injury after cardiopulmonary bypass. METHODS: The efficacy of CY1503 treatment was tested in a lamb model of cardiopulmonary bypass with hypothermic circulatory arrest. Neonatal lambs received CY1503 (n = 6, CPB-CY1503) or saline solution vehicle (n = 7, CPB-saline) into the pump prime before bypass and as a continuous infusion throughout reperfusion. Five lambs served as control animals for in vitro microvessel studies. Indexes of myocardial function (preload recruitable stroke work index, and rate of pressure rise) and pulmonary function (compliance, airway resistance, and arterial PO (2)) were measured before bypass and during reperfusion. The effect of CY1503 on endothelium-dependent vascular reactivity was assessed by means of in vitro pulmonary and coronary microvessel studies. RESULTS: Myocardial function was depressed after circulatory arrest, but CY1503 preserved function near baseline (36% +/- 25% vs 99% +/- 19% of baseline at 3 hours of reperfusion). CY1503-treated animals also demonstrated improved pulmonary function during reperfusion. In vitro microvessel analysis of vascular reactivity revealed endothelial dysfunction after circulatory arrest compared with control lambs. CY1503-treated lambs (CPB-CY1503) had intact endothelial function, as demonstrated by normal vasodilatory responses to endothelium-dependent vasodilators. CONCLUSIONS: CY1503 preserves cardiopulmonary and endothelial function after cardiopulmonary bypass and hypothermic circulatory arrest in neonatal lambs. This suggests a role for selectin-mediated, neutrophil-endothelial interactions in the inflammatory response after cardiac operations.


Asunto(s)
Puente Cardiopulmonar , Paro Cardíaco Inducido , Hipotermia Inducida , Daño por Reperfusión Miocárdica/prevención & control , Oligosacáridos/farmacología , Acetilcolina/farmacología , Análisis de Varianza , Animales , Animales Recién Nacidos , Adhesión Celular/efectos de los fármacos , Vasos Coronarios/efectos de los fármacos , Endotelio Vascular/citología , Endotelio Vascular/efectos de los fármacos , Endotelio Vascular/fisiología , Hemodinámica/efectos de los fármacos , Neutrófilos/fisiología , Nitroprusiato/farmacología , Circulación Pulmonar/efectos de los fármacos , Pruebas de Función Respiratoria , Ovinos , Vasodilatadores/farmacología
9.
Am J Pathol ; 155(6): 2101-13, 1999 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-10595939

RESUMEN

Dilated cardiomyopathy is characterized by decreased contractile function and loss of myofibril organization. Previously unexplored structural and molecular events that precede and initiate dilation can now be studied in tropomodulin-overexpressing transgenic (TOT) mice exhibiting progressive dilated cardiomyopathy. Onset of dilation did not correspond to a change in transgene expression levels, which were more than threefold above normal at birth and remained elevated throughout postnatal life. Similarly, mitogen-activated protein kinase activation (p38, ERK1/ERK2, JNK1/JNK2) was not associated with dilation. In contrast, calcineurin was activated before dilation, presumably due to doubling of intracellular diastolic calcium levels in TOT cardiomyocytes. Amplitude of systolic calcium transients was greatly increased as well, demonstrating the novel and unique calcium handling profile of TOT cardiomyocytes. Loss of myofibril organization was not apparent by confocal microscopy until over 1 week after birth, although neonatal sarcomeric abnormalities were revealed by ultrastructural analysis. Rapid postnatal increases in heart:body weight ratio at 1.5 weeks were followed by two waves of mortality between 2 and 3 weeks after birth coincident with maturational stress. Ultimately, TOT pathogenesis is a compensatory response to altered sarcomeric structure driven by calcineurin activation within days after birth, making TOTs an excellent paradigm for studying the role of calcium overload in dilated cardiomyopathy.


Asunto(s)
Cardiomiopatía Dilatada/etiología , Cardiomiopatía Dilatada/patología , Proteínas Portadoras/genética , Animales , Calcio/metabolismo , Cardiomiopatía Dilatada/metabolismo , Proteínas Portadoras/biosíntesis , Immunoblotting , Ratones , Ratones Transgénicos , Proteínas de Microfilamentos/biosíntesis , Transducción de Señal , Tropomodulina
10.
Am J Public Health ; 89(11): 1708-14, 1999 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-10553393

RESUMEN

OBJECTIVES: This study was done to assess changes in obesity and risk factors for cardiovascular disease (CVD) in Black and White children from 1975 through 1990. METHODS: A cross-sectional study of body composition and CVD risk factors conducted in a school district as part of the Lipid Research Clinics (LRC) Program Prevalence Study (1973-1975) was compared with a later study (1989-1990) conducted in the same school district, which remained demographically stable. The studies included 1456 third- and fifth-grade students and 300 LRC subjects within the same age ranges. RESULTS: Students in the 1989-1990 study had a significantly higher mean body mass index (BMI), total blood cholesterol concentration, and systolic and diastolic blood pressures and marginally higher resting heart rates than those in the earlier study. The prevalence of obesity increased from 12.5% to 25.3%, and of hypercholesterolemia from 8.0% to 14.8%. Black females had the largest increase in BMI and resting heart rate and the highest prevalence of elevated total cholesterol in the 1989-1990 study. CONCLUSIONS: The results of this study suggest a secular trend toward increased obesity in children and portend the potential development of a public health problem that could reverse the recent decline in morbidity from CVD.


Asunto(s)
Población Negra , Enfermedades Cardiovasculares/etnología , Enfermedades Cardiovasculares/etiología , Población Blanca , Adolescente , Factores de Edad , Presión Sanguínea , Índice de Masa Corporal , Enfermedades Cardiovasculares/sangre , Niño , Estudios Transversales , Femenino , Frecuencia Cardíaca , Humanos , Lípidos/sangre , Masculino , Ohio/epidemiología , Factores de Riesgo , Factores Sexuales , Población Suburbana/estadística & datos numéricos
11.
Am Heart J ; 136(4 Pt 1): 714-7, 1998 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-9778076

RESUMEN

BACKGROUND: Echocardiography is sometimes performed to identify candidates for coil embolization of patent ductus arteriosus (PDA). Therefore we attempted to determine the validity of color Doppler echocardiography to accurately determine the minimum PDA diameter. METHODS AND RESULTS: We reviewed data from 27 children (median 3.8 years, range 1 to 15 years) with PDAs and measured their minimum ductal diameters by color flow Doppler echocardiography and by angiography. We found that there were significant mean differences between the color Doppler and angiographic measurements (2.7+/-0.8 vs 1.6+/-0.7 mm, P< .001) with color Doppler exceeding angiographic measurements by > or = 1.0 mm in 15 (56%) of 27 patients. More importantly, color Doppler measured a PDA > or = 4.0 mm (usually greater than that recommended for coiling) in 3 (11%) patients in whom the angiographic measurement was <4.0 mm. Correlation analysis demonstrated no correlation between the color Doppler and angiographic measurements (r2 = 0.17, P= .04, SEE = 0.2 mm). CONCLUSIONS: These data suggest that color Doppler echocardiography often overestimates the true minimum PDA diameter, therefore we recommend that a color Doppler-based recommendation that a PDA is too large for transcatheter coil occlusion not be used exclusively to exclude a patient from this treatment modality.


Asunto(s)
Conducto Arterioso Permeable/diagnóstico por imagen , Ecocardiografía Doppler en Color , Adolescente , Niño , Preescolar , Angiografía Coronaria/métodos , Ecocardiografía Doppler en Color/métodos , Femenino , Humanos , Lactante , Masculino , Reproducibilidad de los Resultados , Estudios Retrospectivos
12.
J Am Coll Cardiol ; 32(3): 766-72, 1998 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-9741525

RESUMEN

OBJECTIVES: This study sought to evaluate the effects of veno-venous ultrafiltration on myocardial contractility in children undergoing cardiopulmonary bypass (CPB) for repair of congenital heart defects. BACKGROUND: Ultrafiltration (UF) is currently used to diminish postoperative fluid accumulation following CPB in children. Previous reports indicate improvement in hemodynamics immediately after UF, but the mechanism of its action is unknown. METHODS: Twenty-three patients (ages 2 months to 9.1 years; 13 males, 10 females) underwent UF for 10 min after CPB. Twelve patients underwent UF immediately after CPB (Group A). They were studied: (1) before and (2) after CPB, (3) after UF, and (4) 10 min after UF. Eleven patients underwent UF 10 min after CPB (Group B). They were studied: (1) before and (2) after CPB, (3) after a 10-min delay before UF, and (4) after UF. Contractility was determined by the difference in the observed and predicted velocity of circumferential fiber shortening for the measured wall stress, using transesophageal echocardiography. Left ventricular wall thickness was also measured. RESULTS: There was significant improvement in contractility after UF in both groups (mean+/-SD, Group A: -0.28+/-0.13 to -0.01+/-0.21 circ/s, p < 0.05; Group B: -0.26+/-0.16 to -0.11+/-0.17 circ/s, p < 0.05). Myocardial thickness to cavity dimension decreased in both groups following UF (Group A: 0.19+/-0.04 to 0.14+/-0.03, p < 0.05; Group B: 0.18+/-0.04 to 0.14+/-0.03, p < 0.05). CONCLUSIONS: UF improves hemodynamics by improving contractility and possibly by reducing myocardial edema in children following cardiac surgery. Enhanced patient outcome after ultrafiltration may in part be due to these changes.


Asunto(s)
Cardiopatías Congénitas/cirugía , Hemofiltración , Cuidados Posoperatorios , Puente Cardiopulmonar , Niño , Preescolar , Ecocardiografía Transesofágica , Femenino , Cardiopatías Congénitas/fisiopatología , Hemodinámica/fisiología , Humanos , Lactante , Masculino , Contracción Miocárdica/fisiología , Complicaciones Posoperatorias/fisiopatología , Estudios Prospectivos
13.
J Pediatr ; 133(1): 46-50, 1998 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-9672509

RESUMEN

Lack of a decline in nocturnal blood pressure is associated with an adverse effect on end organs in adults with insulin-dependent diabetes mellitus (IDDM). The role of the decline in nocturnal blood pressure in young patients with IDDM is not known. We studied 25 white subjects with IDDM (age = 20.8 +/- 3.7 years, mean +/- SD), 8 of whom were female. The duration of IDDM in these subjects was 12.9 +/- 5.4 years (mean +/- SD). We determined the values for glycosylated hemoglobin (HgbA1), 24-hour ambulatory blood pressure, diastolic cardiac function (the ratio of peak E wave to peak A wave velocity (E/A) and indexed peak filling rate ¿PFR/SV¿ by Doppler echocardiography), and albumin excretion rate. The HgbA1 level was 10.9% +/- 1.9% (mean +/- SD; normal range = 4.5%-8.5%). The HgbA1 concentration was inversely correlated (p < 0.005) with the decline in systolic (r = 0.57) and diastolic (r = -0.55) nocturnal blood pressure. Diastolic cardiac dysfunction ¿E/A ratio [r = 0.42, p < 0.03) and PFR/SV (r = 0.52, p < 0.01)¿ correlated with a smaller decrease in nocturnal diastolic blood pressure. An inverse correlation between decline in nocturnal systolic blood pressure and log albumin excretion rate (r = -0.37, p = 0.07) approached statistical significance. We conclude that poor glycemic control adversely affects nocturnal blood pressure and that the latter may play an important role in cardiac and possibly renal dysfunction in early IDDM.


Asunto(s)
Presión Sanguínea/fisiología , Diabetes Mellitus Tipo 1/fisiopatología , Función Ventricular/fisiología , Adolescente , Adulto , Monitoreo Ambulatorio de la Presión Arterial , Ritmo Circadiano , Creatina/orina , Diabetes Mellitus Tipo 1/sangre , Femenino , Hemoglobina Glucada/análisis , Ventrículos Cardíacos/diagnóstico por imagen , Humanos , Modelos Lineales , Masculino , Ultrasonografía
14.
Am J Physiol ; 274(5): H1828-35, 1998 05.
Artículo en Inglés | MEDLINE | ID: mdl-9612396

RESUMEN

The purposes of this study were to assess load-independent, end-systolic relationships in mice and compare these relationships to ejection phase indexes in assessing contractility. In 13 mice, ejection phase indexes (shortening fraction and velocity of fiber shortening) and end-systolic relationships [pressure-dimension relationship (ESPDR) and stress-velocity relationship (ESSVR)] were determined using M-mode echocardiography and simultaneous left ventricular pressure. Load was altered with phenylephrine and nitroprusside. Contractility was increased with dobutamine and decreased by induction of hypothyroidism. Ejection phase indexes increased with dobutamine infusion but were not significantly decreased with hypothyroidism. However, end-systolic relationships changed significantly with both dobutamine (gamma-intercepts: ESPDR from 22 to 48 mmHg, ESSVR from 3.7 to 6.6 circ/s, P < 0.05) and hypothyroidism (gamma-intercepts: ESPDR from 22 to 11 mmHg, ESSVR from 3.7 to 3.2 circ/s, P < 0.05). We conclude that end-systolic indexes can be accurately measured in the intact mouse by echocardiography with simultaneous left ventricular pressure recording and appear to be more sensitive to inotropic state than ejection phase indexes.


Asunto(s)
Ecocardiografía/métodos , Corazón/fisiología , Animales , Velocidad del Flujo Sanguíneo , Ratones , Contracción Miocárdica , Volumen Sistólico
15.
J Am Soc Echocardiogr ; 11(4): 349-55, 1998 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-9571584

RESUMEN

Diastolic dysfunction is an early harbinger for systolic dysfunction in insulin-dependent diabetes mellitus (IDDM). To determine the role of automated border detection (ABD) in detecting diastolic abnormalities and whether IDDM control correlates with abnormalities, 21 young IDDM patients (22 +/- 4 years old) and 19 control subjects underwent echocardiography. ABD indices included the percent contribution to total left ventricular filling of the three phases of diastole (rapid filling, diastasis, and atrial contraction) and peak filling rate. Doppler indices included E/A ratio and peak filling rate. Rapid filling phase was lower in the IDDM patients compared with control subjects (73% +/- 5% versus 80% +/- 5%, p = 0.0006), and atrial contraction filling was higher (19% +/- 4% versus 14% +/- 3%, p = 0.0003). Doppler indexes showed similar changes. Glycosylated hemoglobin, insulin dosage, and duration of IDDM since puberty were associated with filling abnormalities. Young patients with IDDM have increased atrial contraction and reduced rapid filling phases detected by automatic border detection, and these diastolic abnormalities are related to the diabetic disease process.


Asunto(s)
Diabetes Mellitus Tipo 1/complicaciones , Ecocardiografía Doppler , Disfunción Ventricular Izquierda/diagnóstico por imagen , Adulto , Función Atrial , Diabetes Mellitus Tipo 1/fisiopatología , Diástole , Femenino , Humanos , Masculino , Contracción Miocárdica , Variaciones Dependientes del Observador , Disfunción Ventricular Izquierda/complicaciones
16.
J Am Soc Echocardiogr ; 11(2): 132-7, 1998 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-9517552

RESUMEN

We report the results of a prospective study of pulmonary venous (PV) flow Doppler velocities in 68 normal children. We sought to establish the normal PV flow velocities in the broad pediatric population, compare these velocities to heart rate and age. In normal children, there is a wide range of PV flow velocities, most of which correlate with age and heart rate. However, the PV flow velocities and their durations do not distinguish the age groups. The peak velocity of systolic forward flow and atrial reversal flow in the pulmonary vein were independent of heart rate. The PV flow peak systolic velocity showed a weak correlation with the velocity of the mitral inflow early wave. However, the velocity of atrial reversal flow showed no correlation with the mitral inflow A velocity (late wave), which is generated by the same force of atrial contraction.


Asunto(s)
Velocidad del Flujo Sanguíneo , Ecocardiografía Doppler , Venas Pulmonares/diagnóstico por imagen , Adolescente , Adulto , Niño , Preescolar , Frecuencia Cardíaca , Humanos , Lactante , Recién Nacido , Estudios Prospectivos , Venas Pulmonares/fisiología , Valores de Referencia , Sístole
17.
Pediatrics ; 99(6): 804-7, 1997 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-9164773

RESUMEN

OBJECTIVE: To evaluate whether body mass index (BMI) is a representative equivalent measure of body fatness independent of age, race, gender, sexual maturation, and distribution of fat in children and adolescents. STUDY DESIGN: Cross-sectional study of 192 healthy subjects (100 boys and 92 girls, 103 white and 89 black) age 7 to 17 years. Methods. Height and weight were measured in the standard fashion, and BMI (kg/m) was calculated from these values. Fat mass and percent body fat were determined using dual-energy x-ray absorptiometry. Sexual maturation was evaluated by physical assessment. Distribution of fat was determined by the waist:hip ratio. RESULTS: There were no significant differences by gender and ethnic group for any of the demographic or anthropometric variables, except waist:hip ratio, which was higher in white compared with black boys. BMI was significantly and positively correlated with age, stage of maturation, and all of the anthropometric variables in each race-sex group. The correlation of maturation stage with BMI was stronger than the correlation between age and BMI. A multiple regression analysis showed that BMI, gender, race, sexual maturation, and distribution of fat were all significant independent correlates of the percent body fat (multiple R = .77). The percent body fat-BMI relationship was dependent on the stage of sexual maturation, gender (for an equivalent BMI, girls have greater amounts of body fat than boys), race (for equivalent BMI, whites have higher body fat than blacks), and waist:hip ratio (for equivalent BMI, those with central obesity have greater body fatness than those with peripheral obesity). CONCLUSION: BMI is not an equivalent measure of the percent body fat for each race-sex group. When BMI is used as a measure of body fatness in a research or clinical setting, particularly when comparisons are made across race and gender, it may be important to consider the maturation stage, race, gender, and distribution of body fat in the interpretation of the results.


Asunto(s)
Tejido Adiposo , Índice de Masa Corporal , Obesidad , Absorciometría de Fotón , Adolescente , Factores de Edad , Niño , Estudios Transversales , Femenino , Humanos , Masculino , Pubertad , Grupos Raciales , Análisis de Regresión , Factores Sexuales
18.
J Am Soc Echocardiogr ; 10(9): 964-72, 1997.
Artículo en Inglés | MEDLINE | ID: mdl-9440074

RESUMEN

A noninvasive method to detect heart transplant rejection would allow for increased monitoring at reduced risk. Automatic border detection is a new method to assess diastolic abnormalities. The purpose of this study was to determine whether automatic border detection of left ventricular filling detects rejection in children. Nineteen episodes of biopsy-proven rejection in 10 children were retrospectively reviewed. Echocardiograms during rejection were compared with those before rejection and during recovery. Automatic border detection indices were percentage of total left ventricular filling as a result of rapid filling, diastasis, and atrial contraction. The percentage of total ventricular filling during diastasis increased significantly during rejection (10% +/- 6% versus 15% +/- 8%, p = 0.02), and the percentage of filling during the rapid filling phase decreased during rejection (82% +/- 8% versus 77% +/- 11%, p = 0.08). These changes were even more marked for the most severe episodes of rejection. These changes resolved at recovery. Automatic border detection of left ventricular filling patterns are altered during cardiac rejection in children. Filling during diastasis increases significantly, and filling during the rapid filling phase decreases. A prospective analysis is needed to determine whether these changes in filling can obviate the need for cardiac biopsy.


Asunto(s)
Rechazo de Injerto/diagnóstico por imagen , Trasplante de Corazón/diagnóstico por imagen , Aumento de la Imagen , Función Ventricular Izquierda , Adolescente , Niño , Preescolar , Diástole , Ecocardiografía , Endocardio/diagnóstico por imagen , Femenino , Trasplante de Corazón/fisiología , Humanos , Lactante , Recién Nacido , Masculino , Curva ROC , Estudios Retrospectivos
19.
J Am Soc Echocardiogr ; 9(5): 629-36, 1996.
Artículo en Inglés | MEDLINE | ID: mdl-8887865

RESUMEN

In patients with hypoplastic left heart syndrome, the right ventricle is positioned as the systemic ventricle. Monitoring its function is important but difficult because of its unusual position and geometry. The purposes of this study were to determine the feasibility of applying automatic echocardiographic measurements to the evaluation of right ventricular function in patients with hypoplastic left heart syndrome and to compare their function with that of normal subjects. Eleven patients with hypoplastic left heart syndrome (mean age 1.6 years) were evaluated with automatic border detection. Images were adequate if greater than 85% of the endocardium was being tracked. Systolic indexes were fractional area change and peak emptying rate; diastolic indexes were peak filling rate and the proportion of filling that occurred during rapid filling, diastasis, and atrial contraction. These data were compared with those in 18 normal control subjects. Three patients had completed stage 1 (aortic reconstruction, surgical shunt, and atrial septectomy), three patients had completed stage 2 (hemi-Fontan), and five patients had completed stage 3 (Fontan). Images were adequate in all cases. Fractional area change and peak emptying rate were significantly lower in the patients with hypoplastic left heart syndrome compared with control subjects (38% +/- 6% versus 61% +/- 10% and 3.5 +/- 0.9 versus 5.3 +/- 1.3 sec-1, respectively). Peak filling rate was significantly lower (4.1 +/- 1.3 versus 6.6 +/- 2.3 sec-1) and atrial contribution was significantly higher (18% +/- 7% versus 12% +/- 4%) in the patients. Automated echocardiographic analysis is feasible in assessing systemic ventricular function in children with hypoplastic left heart syndrome. These patients have abnormal systolic and diastolic function. Automatic border detection may be useful in detecting and monitoring systemic ventricular dysfunction as these patients progress through the surgical stages of repair.


Asunto(s)
Ecocardiografía/métodos , Síndrome del Corazón Izquierdo Hipoplásico/diagnóstico por imagen , Automatización , Preescolar , Diástole/fisiología , Femenino , Procedimiento de Fontan , Hemodinámica/fisiología , Humanos , Síndrome del Corazón Izquierdo Hipoplásico/fisiopatología , Síndrome del Corazón Izquierdo Hipoplásico/cirugía , Lactante , Recién Nacido , Masculino , Monitoreo Fisiológico , Sístole/fisiología , Función Ventricular Derecha
20.
J Pediatr ; 128(5 Pt 1): 608-15, 1996 May.
Artículo en Inglés | MEDLINE | ID: mdl-8627431

RESUMEN

OBJECTIVE: To determine whether a rise in the diagnosis of non-insulin- dependent diabetes mellitus (NIDDM) has accompanied the rise in obesity in the pediatric population, as it has among adults. STUDY DESIGN: Medical records of 1027 consecutive patients from birth to age 19 years with a diagnosis of diabetes from 1982 to 1995 at a regional, university-affiliated pediatric diabetes referral center were reviewed and classified according to criteria of the National Diabetes Data Group. RESULTS: The number of patients with a diagnosis of NIDDM rose from approximately 4% of new diagnoses of diabetes in patients from birth to age 19 years before 1992, to 16% in 1994. Among patients 10 to 19 years of age, NIDDM accounted for 33% of diagnoses of diabetes in 1994. The incidence of adolescent NIDDM in Greater Cincinnati increased tenfold, from 0.7/100,000 per year in 1982 to 7.2/100,000 per year in 1994. The mean (+/- SD) age and body mass index at presentation were 13.8 +/- 1.9 years and 37.7 +/- 9.6 kg/m2, respectively. The overall female/male ratio was 1.7:1, and female patients were seen 1 year earlier than male patients (p < 0.01). Male subjects had a higher body mass index than female subjects (p < 0.05). A first-degree relative with NIDDM was identified for 65% of patients. At presentation, 21% of the patients had had a diagnosis of at least one other condition associated with obesity. CONCLUSION: There is an increasing incidence of NIDDM among adolescents in Greater Cincinnati, accompanying the national rise in adolescent obesity. Obesity and strong family histories of NIDDM are important risk factors. Because NIDDM leads to long-term morbidity, the prevention of obesity as well as early identification of overt disease, is critical.


Asunto(s)
Diabetes Mellitus Tipo 2/epidemiología , Adolescente , Adulto , Edad de Inicio , Índice de Masa Corporal , Niño , Preescolar , Diabetes Mellitus Tipo 2/etiología , Métodos Epidemiológicos , Femenino , Humanos , Incidencia , Lactante , Masculino , Obesidad/complicaciones , Ohio/epidemiología , Factores Sexuales , Factores Socioeconómicos
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