RESUMO
Neutral endopeptidase (NEP) hydrolyses angiotensins (Ang) I and II and generates angiotensin-(1-7) [Ang-(1-7)]. In humans, the insertion/deletion (I/D) angiotensin-I converting enzyme (ACE) gene polymorphism determined plasma ACE levels by 40%. In rats, a similar polymorphism determines ACE levels which are inversely associated to NEP activity. The objective of this study is to evaluate the relationship between ACE expression and plasma NEP activity in normotensive subjects and in hypertensive patients. In total, 58 consecutive patients with hypertension, evaluated in our Hypertension Clinic, were compared according to their ACE I/D genotypes with 54 control subjects in terms of both plasma ACE activity and NEP activities. Plasma ACE activity was elevated 51 and 70% in both DD ACE groups (normotensives and hypertensives) compared with their respective ID and II ACE groups (P<0.001). A significant effect of the ACE polymorphism and of the hypertensive status on ACE activity was observed (P<0.001). In normotensive DD ACE subjects, NEP activity was 0.30+/-0.02 U/ml, whereas in the normotensive II ACE and in the normotensive ID ACE subjects NEP activity was increased 65 and 48%, respectively (P<0.001). In the hypertensive DD ACE patients, NEP activity was 0.47+/-0.03 U/mg. An effect of the I/D ACE genotypes on NEP activity (P<0.04) and an interaction effect between the I/D ACE genotype and the hypertensive status were also observed (P<0.001). These results are consistent with a normal and inverse relationship between the ACE polymorphism and NEP activity in normotensive humans (as is also observed in rats). This normal relationship is not observed in hypertensive patients.
Assuntos
Hipertensão/enzimologia , Neprilisina/genética , Peptidil Dipeptidase A/genética , Polimorfismo Genético , Análise de Variância , Estudos de Casos e Controles , DNA/sangue , Ecocardiografia , Feminino , Genótipo , Humanos , Hipertensão/genética , Masculino , Pessoa de Meia-Idade , Neprilisina/sangue , Peptidil Dipeptidase A/sangueRESUMO
INTRODUCTION: Angiotensin II levels can be partially inhibited during chronic administration of angiotensin converting enzyme (ACE) inhibitors, limiting from a clinical point of view its efficacy in the treatment of hypertension. There are few studies relating ACE activity directly with early prevention of left ventricular hypertrophy (LVH) in systemic hypertension during the administration of an ACE inhibitor (ACEI). AIM: To evaluate the effects of early ACE inhibition with perindopril on the development of hypertension, LVH and levels of angiotensin II (Ang II) in plasma as well as in LV in the rat Goldblatt model (Gb; 2 kidneys-1 clip), 2 weeks after surgery. RESULTS: Systolic blood pressure and relative LV mass increased by 42% and 20% respectively, in the Gb group (p < 0.001). Plasma and LV ACE activities were significantly higher in the Gb rats compared with the control rats. Plasma and LV Ang II levels also increased by 129% and 800%, respectively. Perindorpil prevented hypertension and LVH development by inhibiting plasma ACE (and also LV ACE), and also circulation Ang II in plasma and in the LV. CONCLUSIONS: In this experimental model of hypertensive LVH, there is an early activation of plasma and cardiac ACE. Early administration of an ACE inhibitor prevents the development of hypertension and LVH by inhibiting the increases of plasma and LV Ang II.
Assuntos
Inibidores da Enzima Conversora de Angiotensina/administração & dosagem , Hipertensão/complicações , Hipertrofia Ventricular Esquerda/prevenção & controle , Perindopril/administração & dosagem , Angiotensina II/análise , Angiotensina II/sangue , Animais , Anti-Hipertensivos/administração & dosagem , Avaliação Pré-Clínica de Medicamentos , Hipertensão/enzimologia , Hipertrofia Ventricular Esquerda/enzimologia , Hipertrofia Ventricular Esquerda/etiologia , Masculino , Peptidil Dipeptidase A/análise , Peptidil Dipeptidase A/sangue , Ratos , Ratos Sprague-DawleyRESUMO
Glucocorticoid-remediable aldosteronism is an inherited disorder caused by a chimeric gene duplication between the CYP11B1 (11beta-hydroxylase) and CYP11B2 (aldosterone synthase) genes. The disorder is characterized by hyperaldosteronism and high levels of 18-hydroxycortisol and 18-oxocortisol, which are under ACTH control. The diagnosis of glucocorticoid-remediable aldosteronism had been traditionally made using the dexamethasone suppression test; however, recent studies have shown that several patients with primary aldosteronism and a positive dexamethasone suppression test do not have the chimeric CYP11B1/CYP11B2 gene. The aim of this work was to evaluate whether other genetic alterations exist in CYP11B genes (gene conversion in the coding region of CYP11B1 or in the promoter of CYP11B2) that could explain a positive dexamethasone suppression test and to determine another genetic cause of glucocorticoid-remediable aldosteronism. We also evaluated the role of 18-hydroxycortisol as a specific biochemical marker of glucocorticoid-remediable aldosteronism. We studied eight patients with idiopathic hyperaldosteronism, a positive dexamethasone suppression test, and a negative genetic test for the chimeric gene. In all patients we amplified the CYP11B1 gene by PCR and sequenced exons 3-9 of CYP11B1 and a specific region (-138 to -284) of CYP11B2 promoter. We also measured the levels of 18-hydroxycortisol, and we compared the results with those found in four subjects with the chimeric gene. None of eight cases showed abnormalities in exons 3-9 of CYP11B1, disproving a gene conversion phenomenon. In all patients a fragment of 393 bp corresponding to a specific region of the promoter of CYP11B2 gene was amplified. The sequence of the fragment did not differ from that of the wild-type promoter of the CYP11B2 gene. The 18-hydroxycortisol levels in the eight idiopathic hyperaldosteronism patients and four controls with chimeric gene were 3.9 +/- 2.3 and 21.9 +/- 3.5 nmol/liter, respectively (P < 0.01). In summary, we did not find other genetic alterations or high levels of 18-hydroxycortisol that could explain a positive dexamethasone suppression test in idiopathic hyperaldosteronism. We suggest that the dexamethasone suppression test could lead to an incorrect diagnosis of glucocorticoid-remediable aldosteronism.
Assuntos
Citocromo P-450 CYP11B2/genética , Dexametasona , Hiperaldosteronismo/genética , Esteroide 11-beta-Hidroxilase/genética , Adulto , Idoso , Quimera , Feminino , Humanos , Hiperaldosteronismo/diagnóstico , Hiperaldosteronismo/tratamento farmacológico , Masculino , Pessoa de Meia-Idade , Regiões Promotoras GenéticasRESUMO
Angiotensin I is a substrate for both ACE and for neutral endopeptidase 24.11 (NEP). We hypothesized that high ACE expression is related to low NEP activity. Accordingly, circulating and tissue NEP and ACE activities were measured by fluorometry in homozygous rats (F(0) and F(2)) for the Lewis microsatellite allele (LL, low ACE) and for the Brown Norway microsatellite allele (BB, high ACE). Plasma, lung, and aortic ACE activities in F(0) and F(2) were higher in BB rats than in LL rats (P<0.01), whereas left ventricular ACE activity was similar in both genotypes. In contrast, NEP activity in the LL group was higher in the serum, aorta, and lungs in F(0) and F(2) homozygous (P<0.05). Plasma ACE activity was inversely correlated with serum (r=-0.6 and -0.598 in F(0) and F(2), respectively; P<0.03) and lung NEP activities (r=-0.77 in F(0) and r=-0.59 in F(2), P<0.01). Aortic ACE and NEP activities were also correlated (r=-0.696 and -0.584 in F(0) and F(2), respectively; P<0.03). In conclusion, genetically determined high ACE expression in rats is inversely related to tissue NEP activity, which could determine lower angiotensin-(1-7) tissue levels.
Assuntos
Endopeptidases/metabolismo , Peptidil Dipeptidase A/metabolismo , Animais , Aorta/enzimologia , Pressão Sanguínea/fisiologia , Endopeptidases/sangue , Feminino , Genótipo , Ventrículos do Coração/enzimologia , Pulmão/enzimologia , Masculino , Peptidil Dipeptidase A/sangue , Peptidil Dipeptidase A/genética , Polimorfismo Genético , Ratos , Ratos Endogâmicos BN , Ratos Endogâmicos LewRESUMO
BACKGROUND: Patients with chronic cardiac failure often have elevated plasma uric acid levels, that are associated to a dismal prognosis. AIM: To investigate possible metabolic mechanisms to explain elevated uric acid levels in these patients. PATIENTS AND METHODS: Eighteen patients with chronic cardiac failure aged 61 +/- 10 years old, without gout or renal failure and not using high doses of diuretics (equal or less than 80 mg/day furosemide or 50 mg/day hydrochlorothiazide) were studied. Plasma uric acid levels were correlated with anaerobic threshold, maximal oxygen uptake, plasma noradrenaline and creatinine and left ventricular ejection fraction, measured radioisotopically. RESULTS: Mean maximal oxygen uptake was 16.6 +/- 4.2 ml/kg/min. There was a negative correlation between uric acid levels and maximal oxygen uptake or maximal oxygen uptake/body surface area (r = 0.521 and -0.533 respectively, p < 0.05). Patients with uric acid levels over 7 mg/dl had a lower anaerobic threshold than patients with lower levels (9.81 +/- 2.41 and 13.08 +/- 3.28 ml/kg/min respectively, p < 0.05). No significant differences in maximal oxygen uptake were observed in these two groups of patients (15.5 +/- 4.24 and 18.08 +/- 3.86 ml/kg/min respectively). Uric acid levels did not correlate with plasma noradrenaline, creatinine or left ventricular ejection fraction. CONCLUSIONS: These results suggest that a defect in cellular oxygenation contributes to the elevation of plasma uric acid levels in patients with chronic cardiac failure.
Assuntos
Limiar Anaeróbio , Baixo Débito Cardíaco/sangue , Consumo de Oxigênio , Ácido Úrico/sangue , Idoso , Baixo Débito Cardíaco/fisiopatologia , Doença Crônica , Creatinina/sangue , Diuréticos/efeitos adversos , Humanos , Masculino , Ventilação Voluntária Máxima , Pessoa de Meia-Idade , Norepinefrina/sangueRESUMO
BACKGROUND: Patients with chronic heart failure have a lower inspiratory muscle strength and fatigue endurance. AIM: To assess the effects of selective training of respiratory muscles in patients with heart failure. PATIENTS AND METHODS: Twenty patients with stable chronic heart failure, aged 58.3 +/- 3 years with an ejection fraction of 28 +/- 9%, were subjected to respiratory muscle training with threshold valves. The load was fixed in 30% of maximal inspiratory pressure (PImax) in 11 and in 10% of PImax in nine. Two sessions of 15 minutes, 6 days per week, during 6 weeks were done. Degree of dyspnea (Mahler score), maximal oxygen uptake, distance walked in 6 minutes, respiratory muscle function and left ventricular ejection fraction were measured before and after training. RESULTS: Both training loads were associated to an improvement in dyspnea (+2.7 +/- 1.8 and +2.8 +/- 1.8 score points with 30% PImax and 10% PImax respectively), maximal oxygen uptake (from 19 +/- 3 to 21.6 +/- 5 and from 16 +/- 5 to 18.6 +/- 7 ml/kg/min with 30% PImax and 10% PImax respectively, p < 0.05), PImax (from 78 +/- 22 to 99 +/- 22 and from 72 +/- 34 to 82.3 cm H20 with 30% PImax and 10% PImax respectively), sustained PImax (from 63 +/- 18 to 90 +/- 22 and from 58 +/- 3 to 69 +/- 3 cm H20 with 30% PImax and 10% PImax respectively), and maximal sustained load (from 120 +/- 67 to 195 +/- 47 and from 139 +/- 120 to 192 +/- 154 g with 30% PImax and 10% PImax respectively). The distance walked in 6 min only increased in subjects trained at 30% PImax (from 451 +/- 78 to 486 +/- 68 m). CONCLUSIONS: Selective training of respiratory muscles results in a functional improvement of patients with chronic heart failure.
Assuntos
Exercícios Respiratórios , Insuficiência Cardíaca/reabilitação , Músculos Respiratórios/fisiopatologia , Doença Crônica , Tolerância ao Exercício , Feminino , Insuficiência Cardíaca/fisiopatologia , Humanos , Capacidade Inspiratória , Masculino , Pessoa de Meia-IdadeRESUMO
BACKGROUND: Heart transplantation currently provides the most effective treatment for advanced heart failure. However, medical therapy for this condition has also improved, heart donors are scarce and the cost of the procedure is high. Therefore the indications and management of these patients need reevaluation. AIM: To analyze the results of 24 patients submitted to heart transplantation for end-stage heart failure needing repeated hospitalizations and i.v. inotropes for compensation. PATIENTS AND METHODS: The group was comprised by 21 men and 3 women with a mean age of 36.8 years, mean left ventricular ejection fraction 19 +/- 4.5%, mean systolic pulmonary artery pressure 48 +/- 13 mmHg (24-70) and mean pulmonary vascular resistance 2.6 Wood Units (1-5). Fourteen patients (58%) had a previous median sternotomy. Immunosuppression did not include induction therapy and steroids were discontinued early. RESULTS: Operative mortality was 4% at 30 days. Actuarial survival at one year was 90% and at 5 years 72%. Freedom from rejection at one year was 76% and at 5 years 50%. Freedom from infection was 70% at one year and 56.5% at five years. All patients with more than 3 months of follow-up were in functional class I. CONCLUSIONS: These results justify the proposed modifications for transplantation protocols.
Assuntos
Insuficiência Cardíaca/cirurgia , Transplante de Coração/métodos , Análise Atuarial , Adolescente , Adulto , Protocolos Clínicos , Intervalo Livre de Doença , Feminino , Seguimentos , Rejeição de Enxerto/tratamento farmacológico , Rejeição de Enxerto/imunologia , Humanos , Terapia de Imunossupressão/métodos , Masculino , Pessoa de Meia-Idade , Estudos ProspectivosRESUMO
BACKGROUND: There is little information about the real prevalence of hypertension in Chile. AIM: To assess the adjusted prevalence of hypertension and its main therapeutic measures among adults living in Valparaiso, Chile. MATERIALS AND METHODS: A random sample of dwellings in Valparaiso was chosen. Among these, an individual of 25 to 64 years old was randomly surveyed for risk factors for chronic diseases and sociodemographic parameters. Blood pressure, weight, height, oral glucose tolerance test, fasting cholesterol and triglycerides were also measured. Prevalence was pondered according to age, sex, and probability of selection in the dwelling interior. RESULTS: Three thousand one hundred twelve individuals were studied. The adjusted prevalence of hypertension was 11.4% (11.6% among females and 10.6% among men). The prevalence increased along with age from 3 and 1.9% in men and women of 25 to 34 years old respectively, to 18.2 and 27.4% among men and women of 55 to 64 years old (p < 0.01). People of low socioeconomic level had a higher prevalence of hypertension than those of high socioeconomic level (14.2 and 9.3% respectively, P < 0.05). Diabetes, obesity and hypercholesterolemia were significantly more frequent in subjects with hypertension than in the general population. Forty-four percent of diagnosed hypertensives were receiving medications (angiotensin converting enzyme inhibitors 40%, calcium antagonists 34%, beta blockers 22%). Twenty five percent of patients were treated with a combination of medications. Of those treated, only 22% had normal blood pressure levels at the moment of examination. CONCLUSIONS: High blood pressure is an important public health problem that requires more efficient detection and treatment programs.
Assuntos
Hipertensão/epidemiologia , Adulto , Distribuição por Idade , Fatores Etários , Chile/epidemiologia , Estudos Transversais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Prevalência , Fatores de Risco , Distribuição por Sexo , Fatores Sexuais , Fatores SocioeconômicosRESUMO
The aim of this study was to estimate the prevalence of the different alleles of the angiotensin converting enzyme (ACE) gene insertion/deletion (I/D) polymorphism and associated plasma ACE activity, as well as cardiac echocardiographic structure, in a healthy Chilean population. We selected 117 healthy normotensive subjects (aged 45 to 60 years, middle socioeconomic status, nonobese, and nondiabetic) from a population-based study concerning the prevalence of risk factors for chronic diseases (Conjunto de Acciones Para la Reducción Multifactorial de las Enfermedades no Transmisibles [CARMEN]). The frequencies of the I and D alleles were 0.57 and 0.43, respectively. Mean plasma ACE activity was 15.3 +/- 3.9 U/mL. Compared with subjects with the II genotype, plasma ACE activity was significantly higher in subjects with the ID and DD genotypes with no difference between them. No correlation was observed between blood pressure and plasma ACE activity. Among the three different genotypes there was no difference in left ventricular (LV) dimensions or in LV mass. No correlation between plasma ACE activity and LV mass was observed for either gender or different genotypes. Multivariate linear regression analysis using LV mass and LV mass index as dependent variables showed independent effects (P < .05) for gender (higher LV mass in men) and diastolic blood pressure, but not for the DD genotype. In conclusion, in this population, the presence of the D allele on the ACE gene determined higher circulating ACE activity. However, in this normotensive healthy population, male gender and diastolic blood pressure, but not the presence of the D allele, were associated with increased LV mass.
Assuntos
Elementos de DNA Transponíveis/genética , Deleção de Genes , Peptidil Dipeptidase A/sangue , Peptidil Dipeptidase A/genética , Polimorfismo Genético/genética , Função Ventricular , Alelos , Pressão Sanguínea/fisiologia , Doenças Cardiovasculares/sangue , Doenças Cardiovasculares/genética , Doenças Cardiovasculares/fisiopatologia , Chile , Doença Crônica , DNA/análise , Primers do DNA/química , Ecocardiografia , Feminino , Marcadores Genéticos/genética , Genótipo , Ventrículos do Coração/diagnóstico por imagem , Humanos , Masculino , Pessoa de Meia-Idade , Contração Miocárdica/fisiologia , Reação em Cadeia da Polimerase , Valores de Referência , Fatores de Risco , Espectrometria de Fluorescência , Inquéritos e QuestionáriosRESUMO
Continuous ambulatory blood pressure monitoring is a diagnostic technique devised as a consequence of the great variations in blood pressure measurements. It allows multiple daily measurements, nocturnal monitoring, avoids the stress of blood pressure measurements, gives a picture of pressure behavior during 24 hours and reduces observer related errors. The equipment used must be accurate and validated using international protocols. Accepted indications for continuous ambulatory blood pressure monitoring are white coat hypertension, episodic hypertension, resistance to medications and assessment of symptoms or autonomic dysfunction. Other indications with less clear cut usefulness, are high risk cardiac, renal or pregnant patients and an accurate blood pressure control. We describe equipment calibration, elements that must be considered in the reports, result interpretation and conclusions. Normal blood pressure ranges for children and pregnant women are also reported.
Assuntos
Monitorização Ambulatorial da Pressão Arterial/normas , Fatores Etários , Monitorização Ambulatorial da Pressão Arterial/instrumentação , Monitorização Ambulatorial da Pressão Arterial/métodos , Chile , Feminino , Humanos , Masculino , Fatores Sexuais , Sociedades Médicas/normas , Fatores de TempoRESUMO
There is evidence that insulin-like growth factor-1 (IGF-1) plays a role in the development of left ventricular hypertrophy, but it is uncertain whether cardiac IGF-1 changes before or after hypertension is established, and whether circulating IGF-1 are involved in cardiac hypertrophy. We have investigated changes in circulating and left ventricular IGF-1 and in the expression of the IGF-1 gene in the left ventricles of rats during the development of hypertensive left ventricular hypertrophy (Goldblatt model; 2 kidney-1 clamped). Our results show that the left ventricular contents of IGF-1 and its mRNA were increased at one and four weeks of hypertension and hypertrophy, and that both returned to control values after nine weeks. These changes were unrelated to the seric concentration of IGF-1 in the blood. These results show that local rather than circulating IGF-1 levels contributed to the development of renovascular hypertensive left ventricular hypertrophy.
Assuntos
Hipertrofia Ventricular Esquerda/metabolismo , Fator de Crescimento Insulin-Like I/metabolismo , Miocárdio/metabolismo , Animais , Modelos Animais de Doenças , Expressão Gênica , Ventrículos do Coração/metabolismo , Ventrículos do Coração/patologia , Hipertensão Renovascular/complicações , Hipertrofia Ventricular Esquerda/etiologia , Hipertrofia Ventricular Esquerda/patologia , Fator de Crescimento Insulin-Like I/genética , Masculino , Ratos , Ratos Sprague-Dawley , Fatores de TempoRESUMO
BACKGROUND: A temporal alteration between atrial and ventricular contraction, in which the last one would be abnormally retarded, could exist in patients with dilated cardiomyopathy. This alteration could have adverse hemodynamic effects. AIM: To study the hemodynamic modifications caused by an artificial shortening of AV interval in patients with dilated cardiomyopathy. PATIENTS AND METHODS: Nine patients with dilated cardiomyopathy were studied. Hemodynamic and tissular perfusion values, echocardiographic and radioisotopic ventricular function parameters were measured before and after six hours of AV interval shortening with electrical stimulation of the heart. RESULTS: After electrical stimulation, cardiac output increased from 3.38 +/- 0.8 to 3.87 +/- 0.79 l/min (p< 0.05). Pulmonary capillary pressure decreased from 23.8 +/- 8.9 to 19.8 +/- 9.2 mm Hg (p = NS). There were no significant changes in ventricular function parameters or in systemic and pulmonary pressures. CONCLUSIONS: Electrical shortening of AV interval in patients with dilated cardiomyopathy increases cardiac output but does not change ventricular function parameters.
Assuntos
Cardiomiopatia Dilatada/fisiopatologia , Terapia por Estimulação Elétrica/efeitos adversos , Contração Miocárdica , Função Ventricular , Adulto , Idoso , Débito Cardíaco , Baixo Débito Cardíaco/fisiopatologia , Hemodinâmica , Humanos , Masculino , Pessoa de Meia-Idade , Fatores de TempoRESUMO
BACKGROUND: Administration of angiotensin converting enzyme (ACE) inhibitors to patients with congestive heart failure (CHF) is associated to a decrease in the abnormal vasoconstrictor neurohormonal activity. This contributes to the sustained benefits of these drugs on symptoms and survival of patients with CHF. There is little information, however, regarding the effects of ACE inhibition on vasodilator and natriuretic hormones. AIM: To evaluate the chronic effects of enalapril, in addition to digitalis and diuretics in patients with chronic cardiac failure. PATIENTS AND METHODS: Nine patients with an idiopathic dilated cardiomyopathy (8 male, aged 48 to 76 years old) under treatment with digitalis and diuretics, received enalapril 20 mg bid during eight weeks. Before and after this treatment period resting left ventricular ejection fraction, functional class, plasma levels of atrial natriuretic factor and bradykinins (BK) and urinary excretion of kalikreins (BK) and prostaglandin E2 (PGE2) were measured. RESULTS: After enalapril therapy, there was a significant increase in maximal O2 consumption (14.8 +/- 1.2 to 18.6 +/- 1.5 ml/kg/min, p < 0.05) and radionuclide LV ejection fraction (27.4 +/- 1.1 to 31.4 +/- 0.9% p < 0.05). This was associated with a significant decrease in plasma ANP levels (559 +/- 158 to 178 +/- 54.8 pg/ml) and UK (391 +/- 112 to 243 +/- 92 Cu/24 h). CONCLUSIONS: The decrease in ANP levels, which is a well known marker of prognosis in CHF, could contribute to explain the sustained clinical benefits observed with ACE inhibitors in patients with CHF.
Assuntos
Inibidores da Enzima Conversora de Angiotensina/farmacologia , Baixo Débito Cardíaco/fisiopatologia , Cardiomiopatia Dilatada/fisiopatologia , Enalapril/farmacologia , Consumo de Oxigênio/efeitos dos fármacos , Volume Sistólico/efeitos dos fármacos , Vasodilatadores/farmacologia , Idoso , Fator Natriurético Atrial/sangue , Bradicinina/sangue , Doença Crônica , Dinoprostona/urina , Feminino , Humanos , Calicreínas/urina , Masculino , Pessoa de Meia-IdadeRESUMO
BACKGROUND: Experimental and preliminary clinical data in patients with dilated cardiomyopathy show that growth hormone has a positive inotropic effect and contributes to peripheral vasodilatation. However, there is little information about the activity of growth hormone-IGF-1 axis in patients with chronic heart failure. AIM: To measure growth hormone and IGF-1 levels in patients with chronic heart failure. PATIENTS AND METHODS: Nine patients, aged 49 to 76 years old, 7 male, were studied. Seven had an idiopathic dilated cardiomyopathy and 2 a coronary heart disease. All had a stable cardiac failure, in functional capacity II or III and were receiving digoxin, furosemide and potassium supplements. Thyroid hormone levels, basal and exercise growth hormone and IGF-1 levels were measured and compared with reference values for American populations. Left ventricular ejection fraction was measured with an isotopic technique and nutritional status using anthropometry and indirect calorimetry. RESULTS: Anthropometric measures, basal and post-prandial oxygen consumption were within normal limits. Thyroid hormone levels were normal. During maximal exercise, growth hormone levels were 2.56 +/- 4.1 ng/ml and IGF-1 levels were 0.56 +/- 0.61 mU/ml. These values were significantly lower than expected for age and sex. CONCLUSIONS: These patients with chronic cardiac failure have lower than normal growth hormone and IGF-1 levels.
Assuntos
Insuficiência Cardíaca/metabolismo , Hormônio do Crescimento Humano/deficiência , Fator de Crescimento Insulin-Like I/metabolismo , Idoso , Doença Crônica , Feminino , Humanos , Masculino , Pessoa de Meia-IdadeRESUMO
The head-up tilt test has demonstrated to be useful in the study of patients with syncope of unknown origin for the diagnosis of neurocardiogenic syncope. Several publications have described different methods, with different results in cases as well as in controls. We performed a prospective study in a group of normal subjects in order to evaluate the methodology used in our population and to establish its specificity. A positive test was defined as the presence of syncope or presyncope and hypotension. The examination was carried out on a tilt table, five minutes at 0 degree, then at 70 degrees during 20 min. In the absence of syncope or presyncope an i.v. infusion of isoproterenol was started afterwards in order to increase the heart rate 30-50% over the baseline values and administered during 20 min at 70 degrees. Twenty one volunteers (14 male and 7 women; mean age 26.7 +/- 3.5 years; range: 21-33 years) and body mass index 23.4 +/- 2.2 kg/m2 were examined. Mean dose of isoproterenol was 3.1 +/- 0.9 micrograms/min (3.4 +/- 1.1 in men and 2.6 +/- 0.7 micrograms/min in women, NS). During the phase without isoproterenol no subject developed hemodynamic alterations neither symptoms. One volunteer (4.8%) developed presyncope and systemic hypotension (52/28 mm Hg) accompanied with nodal rhythm after 14 min of isoproterenol at 70 degrees, and his examination was discontinued, with immediate recovery. Three other subjects developed asymptomatic transient nodal rhythm during the phase with isoproterenol and recovered spontaneously. No other complications were observed. It is concluded that head-up tilt test with isoproterenol at 70 degrees, with the used doses and heart rate increments, is highly specific (95%) to establish the diagnosis of a neurocardiogenic syncope.
Assuntos
Síncope Vasovagal/diagnóstico , Teste da Mesa Inclinada/métodos , Adulto , Feminino , Humanos , Isoproterenol , Masculino , Estudos ProspectivosRESUMO
OBJECTIVE: To evaluate regression of experimental left ventricular hypertrophy (LVH) in terms of its effects both on myocardial collagen levels and on diastolic stiffness. METHODS: Two-kidney, one clip Goldblatt hypertensive rats were left untreated for 4 weeks (HT4W, n = 12) or 12 weeks (HT12W, n = 11) and compared with rats the treatment of which was started after 4 weeks of hypertension with 30 mg/kg per day losartan for 8 weeks (LOS, n = 12), or 50 mg/l enalapril for 8 weeks (ENA, n = 11). A group of sham-operated rats served as controls (SHAM, n = 9). RESULTS: The blood pressure of the rats increased significantly and LVH developed both after 4 and after 12 weeks of hypertension. Treatment with losartan or enalapril significantly decreased blood pressure and induced complete regression of LVH. Myocardial hydroxyproline concentrations increased in groups HT4W and HT12W (530 +/- 153 and 581 +/- 111 micrograms/g, respectively) relative to that in the SHAM group (421 +/- 22 micrograms/g). None of the treatments induced regression of increased myocardial collagen levels. The slopes of the end-diastolic stress-strain relationships in the isolated beating hearts were significantly higher in HT4W, HT12W and in both treated groups compared with those in the SHAM group, indicating increased diastolic myocardial stiffness. CONCLUSION: Losartan and enalapril treatments decreased blood pressure and induced complete regression of LVH in this model of renovascular hypertension. In contrast, none of the treatments induced regression of increased myocardial collagen levels or reduced the abnormal left ventricular diastolic stiffness. These data suggest that diastolic dysfunction depends more on increased myocardial collagen levels than it does on myocardial mass in this model of pathological LVH.
Assuntos
Colágeno/análise , Diástole , Hipertensão Renovascular/tratamento farmacológico , Hipertrofia Ventricular Esquerda/tratamento farmacológico , Miocárdio/química , Animais , Compostos de Bifenilo/uso terapêutico , Pressão Sanguínea/efeitos dos fármacos , Enalapril/uso terapêutico , Hipertensão Renovascular/fisiopatologia , Hipertrofia Ventricular Esquerda/fisiopatologia , Imidazóis/uso terapêutico , Losartan , Masculino , Ratos , Ratos Sprague-Dawley , Sistema Renina-Angiotensina/fisiologia , Tetrazóis/uso terapêuticoRESUMO
Evaluar los resultados de una serie de 75 pacientes con diagnóstico clínico de HPB, tratados con 5 mg de terazosin por un período mínimo de 6 meses. Los pacientes fueron evaluados clínicamente (I-PSS) y a través de laboratorio, ecografía del aparato urinario y uroflujometría. Esta metodología nos permitió seleccionar a la población apropiada para este tipo de tratamiento: prostatismo mínimo y moderado, flujometría menor de 15 ml/seg y residuo urinario inferior a 100 ml, sin indicaciones absolutas para cirugía. La evaluación permitió objetivar una mejoría sintomática en el 62,5 por ciento (más de 5 puntos) de los pacientes y un aumento del flujo urinario Mx en el 55,17 por ciento, con un promedio de 5,93 ml/seg. Los resultados expresados nos permiten concluir que el tratamiento médico con alfabloqueantes selectivos de larga duración es una alternativa terapeútica válida para un grupo seleccionado de pacientes, según lo consignan las respuestas clínicas y uroflujométricas
Assuntos
Humanos , Masculino , Adulto , Hiperplasia Prostática/diagnóstico , Hiperplasia Prostática/urina , Hiperplasia Prostática , Hiperplasia Prostática/terapiaRESUMO
Evaluar los resultados de una serie de 75 pacientes con diagnóstico clínico de HPB, tratados con 5 mg de terazosin por un período mínimo de 6 meses. Los pacientes fueron evaluados clínicamente (I-PSS) y a través de laboratorio, ecografía del aparato urinario y uroflujometría. Esta metodología nos permitió seleccionar a la población apropiada para este tipo de tratamiento: prostatismo mínimo y moderado, flujometría menor de 15 ml/seg y residuo urinario inferior a 100 ml, sin indicaciones absolutas para cirugía. La evaluación permitió objetivar una mejoría sintomática en el 62,5 por ciento (más de 5 puntos) de los pacientes y un aumento del flujo urinario Mx en el 55,17 por ciento, con un promedio de 5,93 ml/seg. Los resultados expresados nos permiten concluir que el tratamiento médico con alfabloqueantes selectivos de larga duración es una alternativa terapeútica válida para un grupo seleccionado de pacientes, según lo consignan las respuestas clínicas y uroflujométricas(AU)
Assuntos
Humanos , Masculino , Adulto , Hiperplasia Prostática/terapia , Hiperplasia Prostática/diagnóstico , Hiperplasia Prostática/urina , Hiperplasia Prostática/diagnóstico por imagemRESUMO
A 54 years old female patient with a mitral valve prolapse and a rheumatoid arthritis treated with steroids was admitted with dyspnea and hypotension, that started 30 min after taking a pill containing enapril and hydrochlorothiazide. Hemodynamic monitoring with a Swan-Ganz catheter showed a pulmonary capillary pressure of 5 mm Hg, a systemic vascular resistance of 887 (dyn sec)/cm5 and a cardiac output of 10 l/min. The patient had a history of adverse reactions to thiazides and responded to volume replacement, dopamine and steroids.
Assuntos
Anafilaxia/induzido quimicamente , Hipersensibilidade a Drogas , Hemodinâmica , Hidroclorotiazida/efeitos adversos , Edema Pulmonar/induzido quimicamente , Cateterismo de Swan-Ganz , Dopamina/uso terapêutico , Feminino , Humanos , Hidrocortisona/uso terapêutico , Pessoa de Meia-Idade , Edema Pulmonar/diagnóstico por imagem , Edema Pulmonar/tratamento farmacológico , RadiografiaRESUMO
The role of cyclic AMP-dependent protein kinase (PKA) and systolic function during the development of left ventricular hypertrophy (LVH) still remain uncertain. The aim of this work is to study PkA activity and mechanical heart function in two experimental heart hypertrophy models: specifically, one induced by pressure overload (Goldblatt model: two kidneys, one clamped, Gb); and another secondary to myocardial infarction (MI) generated by ligation of the left coronary artery. Hypertension in the Gb group becomes evident by the third and fourth week after surgery without any significant change in the corresponding sham group. The myocardial infarction group did not show any change in systolic pressure. Different degrees of LVH for the two experimental models were observed. Relative cardiac mass (RCM) and relative ventricular mass (RVM) increased 23 and 16%, respectively, above the sham-operated rats in MI group (P < 0.05). For the pressure overload model, the increase values were 42 and 44%, respectively (P < 0.05). Left ventricular hypertrophy was also evaluated through quantitative changes in cardiac beta-myosin heavy chain which agreed with morphometric studies in Goldblatt rats. Ventricular PKA activity did not show any significant difference with respect to the sham-operated group after induction of pressure overload. For the MI model, ventricular PKA activity changed only at day 7 post-infarction with a 289% increase above the sham-operated group (P < 0.05). The absence of activation of ventricular PKA after constriction of renal artery or myocardial infarction was also corroborated by the patterns of PKA-dependent phosphorylated proteins. While force-generating capacity was increased, there was no change in ventricular PKA activity, indicating that there is no relation between this enzyme and systolic stress-strain regression lines in either pressure overload or myocardial infarction conditions. Cyclic AMP-dependent protein kinase activity had no relation with development of cardiac hypertrophy in the two experimental models of LVH. These findings contribute to the hypothesis for a multifactorial interaction of different intracellular biochemical and molecular mechanisms in the genesis of cardiac hypertrophy.