Effects of aging on the secretory apparatus in the right atrial cardiomyocytes of rats.

The cardiac atria secrets polypeptide hormones usually called natriuretic peptides (NPs). These substances play a relevant role in the blood pressure regulation. The objective of the study was to estimate the effects of aging on the secretory apparatus of NPs in cardiomyocytes of the right atrium. Twenty male Wistar rats were studied: 10 young animals aged 3 months old (237 ±â€¯27 g; mean ±â€¯SD) and 10 old animals aged 20 months old (450 ±â€¯68 g; mean ±â€¯SD). The systolic blood pressure was verified instants before the moment of the euthanasia. Electron micrographs were prepared to quantify the area and density of the NP granules and the relative volumes of the endoplasmic reticulum, Golgi complex, and mitochondria. In addition, the number of pores per 10 µm of karyotheca was another variable evaluated. The significance of the results between the two groups evaluated was analyzed by the Student's t test (p < 0.05). The cardiomyocytes obtained from animals of the old group showed decreased in sectional area and density of secretory granules of NP and lower relative volume of endoplasmic reticulum, Golgi complex, and mitochondria compared with the young rats. Moreover, the quantitative density of nuclear pores was significantly lower compared with the youngers. CONCLUSION: Aging causes hypotrophy of the cardiomyocytes of right atrium, similar to what occurs in ventricular cardiomyocytes.

Demographic and clinical characteristics of pulmonary arterial hypertension caused by schistosomiasis are indistinguishable from other etiologies.

INTRODUCTION: Pulmonary arterial hypertension (PAH) is a serious pulmonary circulation disease caused by several etiologies, including schistosomiasis. The present study retrospectively evaluated the clinical and hemodynamic characteristics of patients with schistosomal PAH (PAH-Sch) compared to those of non-Sch PAH patients (non-Sch PAH). METHODS: Patients treated at the Pronto-Socorro Cardiológico de Pernambuco and diagnosed by right cardiac catheterization were divided into PAH-Sch and non-Sch PAH groups. Their socio-demographic and clinical characteristics, N-terminal-pro B-type natriuretic peptide (NT-proBNP), and echocardiography and hemodynamic parameters were retrospectively reviewed. RESULTS: Among the included 98 patients (mean age, 45 ± 14 years; 68 women [69.4%]), we found 56 PAH-Sch and 42 non-Sch PAH. The age distribution was heterogeneous in the PAH-Sch group, with patients predominantly ranging from 50-59 (p <0.004). Dyspnea was the most common symptom, reported by 92 patients (93.8%), and commonly present for over two years prior to diagnosis. Clinical symptoms were similar in both groups, with no differences in functional class, pulmonary artery systolic pressure (p = 0.102), 6-minute walk test score (p = 0.234), NT-proBNP serum levels (p = 0.081), or hemodynamic parameters. CONCLUSIONS: Patients with PAH-Sch present clinical, laboratory, and hemodynamic profiles similar to those with PAH resulting from other etiologies of poor prognosis. PAH is an important manifestation of schistosomiasis in endemic regions that is often diagnosed late.

Demographic and clinical characteristics of pulmonary arterial hypertension caused by schistosomiasis are indistinguishable from other etiologies

Abstract INTRODUCTION: Pulmonary arterial hypertension (PAH) is a serious pulmonary circulation disease caused by several etiologies, including schistosomiasis. The present study retrospectively evaluated the clinical and hemodynamic characteristics of patients with schistosomal PAH (PAH-Sch) compared to those of non-Sch PAH patients (non-Sch PAH). METHODS: Patients treated at the Pronto-Socorro Cardiológico de Pernambuco and diagnosed by right cardiac catheterization were divided into PAH-Sch and non-Sch PAH groups. Their socio-demographic and clinical characteristics, N-terminal-pro B-type natriuretic peptide (NT-proBNP), and echocardiography and hemodynamic parameters were retrospectively reviewed. RESULTS: Among the included 98 patients (mean age, 45 ± 14 years; 68 women [69.4%]), we found 56 PAH-Sch and 42 non-Sch PAH. The age distribution was heterogeneous in the PAH-Sch group, with patients predominantly ranging from 50-59 (p <0.004). Dyspnea was the most common symptom, reported by 92 patients (93.8%), and commonly present for over two years prior to diagnosis. Clinical symptoms were similar in both groups, with no differences in functional class, pulmonary artery systolic pressure (p = 0.102), 6-minute walk test score (p = 0.234), NT-proBNP serum levels (p = 0.081), or hemodynamic parameters. CONCLUSIONS: Patients with PAH-Sch present clinical, laboratory, and hemodynamic profiles similar to those with PAH resulting from other etiologies of poor prognosis. PAH is an important manifestation of schistosomiasis in endemic regions that is often diagnosed late.

Prediction of gestational diabetes mellitus in the first trimester: comparison of maternal fetuin-A, N-terminal proatrial natriuretic peptide, high-sensitivity C-reactive protein, and fasting glucose levels.

OBJECTIVE: We investigated the utility of maternal fetuin-A, N-terminal proatrial natriuretic peptide (pro-ANP), high-sensitivity C-reactive protein (hs-CRP), and fasting glucose levels at 11-14 gestation weeks for predicting pregnancies complicated by gestational diabetes mellitus (GDM). SUBJECTS AND METHODS: This prospective cohort study included 327 low-risk pregnant women who completed antenatal follow-up at a tertiary research hospital between January and April 2014. Maternal blood samples were collected between 11-14 gestational weeks in the first trimester of pregnancy and then stored at -80 °C until further analyses. During follow-up, 29 (8.8%) women developed GDM. The study population was compared 1:2 with age- and body mass index-matched pregnant women who did not develop GDM (n = 59). Fasting plasma glucose (FPG) levels and serum fetuin-A, pro-ANP, and hs-CRP levels were measured using automated immunoassay systems. RESULTS: There was a significant negative correlation between fetuin-A and hs-CRP (CC = -0.21, p = 0.047) and a positive correlation between FPG and hs-CRP (CC = 0.251, p = 0.018). The areas under the receiver operating characteristic curve for diagnosing GDM were 0.337 (p = 0.013), 0.702 (p = 0.002), and 0.738 (p < 0.001) for fetuin-A, hs-CRP, and FPG, respectively. The optimal cut-off values were > 4.65, < 166, and > 88.5 mg/dL for maternal hs-CRP, fetuin-A, and FPG, respectively. CONCLUSION: Reduced fetuin-A, elevated hs-CRP, and FPG levels in women in the first trimester can be used for the early detection of GDM. Further research is needed before accepting these biomarkers as valid screening tests for GDM.

Atrial natriuretic factor: is it responsible for hyponatremia and natriuresis in neurosurgery? / Fator natriurético atrial: ele é o responsável pela hiponatremia e natriurese em neurocirurgia?

OBJECTIVE: To evaluate the presence of hyponatremia and natriuresis and their association with atrial natriuretic factor in neurosurgery patients. METHODS: The study included 30 patients who had been submitted to intracranial tumor resection and cerebral aneurism clipping. Both plasma and urinary sodium and plasma atrial natriuretic factor were measured during the preoperative and postoperative time periods. RESULTS: Hyponatremia was present in 63.33% of the patients, particularly on the first postoperative day. Natriuresis was present in 93.33% of the patients, particularly on the second postoperative day. Plasma atrial natriuretic factor was increased in 92.60% of the patients in at least one of the postoperative days; however, there was no statistically significant association between the atrial natriuretic factor and plasma sodium and between the atrial natriuretic factor and urinary sodium. CONCLUSION: Hyponatremia and natriuresis were present in most patients after neurosurgery; however, the atrial natriuretic factor cannot be considered to be directly responsible for these alterations in neurosurgery patients. Other natriuretic factors are likely to be involved.

Fator natriurético atrial: ele é o responsável pela hiponatremia e natriurese em neurocirurgia? / Atrial natriuretic factor: is it responsible for hyponatremia and natriuresis in neurosurgery?

RESUMO Objetivo: Avaliar a presença de hiponatremia e natriurese, bem como suas associações com o fator natriurético atrial em pacientes de neurocirurgia. Métodos: Foram incluídos 30 pacientes submetidos à ressecção de tumor intracraniano e à clipagem de aneurisma cerebral. Os níveis plasmáticos e urinários de fator natriurético atrial foram medidos durante os períodos pré e pós-operatório. Resultados: Hiponatremia esteve presente em 63,33% dos pacientes, particularmente no primeiro dia pós-operatório. Observou-se natriurese em 93,33% dos pacientes, principalmente no segundo dia pós-operatório. Os níveis plasmáticos de fator natriurético atrial estavam aumentados em 92,60% dos pacientes em pelo menos um dos dias pós-operatórios, mas não houve associação estatisticamente significante entre fator natriurético atrial e sódio plasmático, e entre fator natriurético atrial e sódio urinário. Conclusão: Após neurocirurgia, na maior parte dos pacientes, estiveram presentes hiponatremia e natriurese; contudo, o fator natriurético atrial não pôde ser considerado diretamente responsável por tais alterações nos pacientes neurocirúrgicos. Provavelmente, há o envolvimento de outros fatores natriuréticos.

ABSTRACT Objective: To evaluate the presence of hyponatremia and natriuresis and their association with atrial natriuretic factor in neurosurgery patients. Methods: The study included 30 patients who had been submitted to intracranial tumor resection and cerebral aneurism clipping. Both plasma and urinary sodium and plasma atrial natriuretic factor were measured during the preoperative and postoperative time periods. Results: Hyponatremia was present in 63.33% of the patients, particularly on the first postoperative day. Natriuresis was present in 93.33% of the patients, particularly on the second postoperative day. Plasma atrial natriuretic factor was increased in 92.60% of the patients in at least one of the postoperative days; however, there was no statistically significant association between the atrial natriuretic factor and plasma sodium and between the atrial natriuretic factor and urinary sodium. Conclusion: Hyponatremia and natriuresis were present in most patients after neurosurgery; however, the atrial natriuretic factor cannot be considered to be directly responsible for these alterations in neurosurgery patients. Other natriuretic factors are likely to be involved.

Serum Levels of Cardiac Markers NT-proANP and NT-proBNP in Brachycephalic bitches at Different Gestational Stages.

The aim of this study was to determine serum levels of natriuretic peptide precursors (NT-proANP and NT-proBNP) during pregnancy in brachycephalic bitches. Fifteen healthy multiparous bitches were selected for this prospective study. Serum levels of NT-proANP and NT-proBNP were measured during anoestrous and at 14, 35, 42, 49 and 56 days (2nd, 5th, 6th, 7th and 8th weeks) of pregnancy. Fourteen animals had normal gestations, and one bitch developed single foetus syndrome. The natriuretic peptide levels of this animal were not included in this study; however, it is important to report that its NT-proANP levels were four times greater than those of normal patients. There was no significant difference (p = 0.072) in NT-proBNP levels between anoestrous (0.20 ± 0.10 ng/ml) and the different pregnancy weeks (0.27 ± 0.12 ng/ml). There was a positive correlation (p < 0.0001) between NT-proANP and gestational age, and the levels of this marker increased significantly (p < 0.0001) during the 6th (0.26 ± 0.06 ng/ml), 7th (0.28 ± 0.04 ng/ml) and 8th weeks (0.29 ± 0.05 ng/ml) when compared to anoestrous (0.18 ± 0.02 ng/ml). NT-proANP serum levels are correlated with gestational development and may be indicative of cardiovascular adaptation in canine brachycephalic pregnancy.

Normalization of elevated cardiac, kidney, and hemolysis plasma markers within 48 h in Mexican Tarahumara runners following a 78 km race at moderate altitude.

OBJECTIVES: The aim of this study was to examine to what extent extreme endurance exercise results in changes of plasma markers associated with cardiac and renal damage, as well as hemolysis in male, Mexican Tarahumara runners. METHODS: Ten Tarahumara runners (mean (sd) age of 38 (12) years) participated in a 78 km race in Chihuahua, Mexico at 2,400 m above sea level. Cardiac, kidney, and hematology plasma markers were measured pre-race and <5 min, 1 h, 3 h, 6 h, 24 h, and 48 h post-race. Anthropometry, blood pressure, pulse rate, electrocardiography, HbA1c, hemoglobin and VO2max (estimated from heart rate following step test) were assessed pre-race, while physical activity energy expenditure and intensity were estimated during the race, and oxygen partial pressure saturation (SpO2 ) <30 min post-race. RESULTS: Estimated mean VO2max was 48 (9) mLO2 min(-1) kg(-1) and relative intensity during the race was 68 (11)%VO2 max. Mean SpO2 was 92 (3)% <30 min post-race. Plasma concentrations of especially total creatine kinase, creatine kinase-MB isoform, and haptoglobin changed significantly from pre-race values (P < 0.001) up to 24 h post-race, but had returned to pre-race values after 48 h. The plasma concentrations of mid-regional proatrial natiuretic peptide and copeptin returned to pre-race concentrations after 1 and 6 h, respectively. CONCLUSIONS: Altered cardiac, renal, and hemolysis plasma markers were normalized after 48 h following 78 km of running, suggesting that the impact of exercise-induced cardiac and kidney damage as well as hemolysis in the Mexican Tarahumara is low.

Scale and scope economies in Mexican private medical units / Economías de escala y alcance en unidades médicas privadas en México

Objective. To evaluate technical efficiency and potential presence of scale and scope economies in Mexican private medical units (PMU) that will improve management decisions. Materials and methods. We used data envelopment analysis methods with inputs and outputs for 2 105 Mexican PMU published in 2010 by the Instituto Nacional de Estadística y Geografía from the "Estadística de Unidades Médicas Privadas con Servicio de Hospitalización (PEC-6-20-A)" questionnaire. Results. The application of the models used in the paper found that there is a marginal presence of economies of scale and scope in Mexican PMU. Conclusions. PMU in Mexico must focus to deliver their services on a diversified structure to achieve technical efficiency.

Objetivo. Evaluar la eficiencia técnica y la presencia de potenciales economías de escala y alcance en unidades médicas privadas (UMP) mexicanas, de forma que sea posible establecer planes para la mejora de su gestión. Material y métodos. Se utilizó el método de Análisis Envolvente de Datos con información de insumos y productos para 2 105 UMP del año 2010 publicada por el Instituto Nacional de Estadística y Geografía a través del cuestionario denominado "Estadística de Unidades Médicas Privadas con Servicio de Hospitalización (PEC-6-20-A)". Resultados. La aplicación de los modelos encuentra una presencia marginal de economías de escala y alcance en las UMP mexicanas. Conclusiones. La operación de las UMP en México debe enfocarse a prestar servicios bajo un modelo diversificado para alcanzar mejores niveles de eficiencia técnica.

Renal overexpression of atrial natriuretic peptide and hypoxia inducible factor-1α as adaptive response to a high salt diet.

In the kidney, a high salt intake favors oxidative stress and hypoxia and causes the development of fibrosis. Both atrial natriuretic peptide (ANP) and hypoxia inducible factor (HIF-1α) exert cytoprotective effects. We tested the hypothesis that renal expression of ANP and HIF-1α is involved in a mechanism responding to the oxidative stress produced in the kidneys of rats chronically fed a high sodium diet. Sprague-Dawley rats were fed with a normal salt (0.4% NaCl) (NS) or a high salt (8% NaCl) (HS) diet for 3 weeks, with or without the administration of tempol (T), an inhibitor of oxidative stress, in the drinking water. We measured the mean arterial pressure (MAP), glomerular filtration rate (GFR), and urinary sodium excretion (UVNa). We evaluated the expression of ANP, HIF-1α, and transforming growth factor (TGF-ß1) in renal tissues by western blot and immunohistochemistry. The animals fed a high salt diet showed increased MAP and UVNa levels and enhanced renal immunostaining of ANP, HIF-1α, and TGF-ß1. The administration of tempol together with the sodium overload increased the natriuresis further and prevented the elevation of blood pressure and the increased expression of ANP, TGF-ß1, and HIF-1α compared to their control. These findings suggest that HIF-1α and ANP, synthesized by the kidney, are involved in an adaptive mechanism in response to a sodium overload to prevent or attenuate the deleterious effects of the oxidative stress and the hypoxia on the development of fibrosis.

The role of oxytocin in cardiovascular regulation.

Studies of body volume expansion have indicated that lesions of the anteroventral third ventricle and median eminence block the release of atrial natriuretic peptide (ANP) into the circulation. Detailed analysis of the lesions showed that activation of oxytocin (OT)-ergic neurons is responsible for ANP release, and it has become clear that activation of neuronal circuitry elicits OT secretion into the circulation, activating atrial OT receptors and ANP release from the heart. Subsequently, we have uncovered the entire functional OT system in the rat and the human heart. An abundance of OT has been observed in the early development of the fetal heart, and the capacity of OT to generate cardiomyocytes (CMs) has been demonstrated in various types of stem cells. OT treatment of mesenchymal stem cells stimulates paracrine factors beneficial for cardioprotection. Cardiovascular actions of OT include: i) lowering blood pressure, ii) negative inotropic and chronotropic effects, iii) parasympathetic neuromodulation, iv) vasodilatation, v) anti-inflammatory activity, vi) antioxidant activity, and vii) metabolic effects. OT actions are mediated by nitric oxide and ANP. The beneficial actions of OT may include the increase in glucose uptake by CMs and stem cells, reduction in CM hypertrophy, oxidative stress, and mitochondrial protection of several cell types. In experimentally induced myocardial infarction in rats, continuous in vivo OT delivery improves cardiac healing and cardiac work, reduces inflammation, and stimulates angiogenesis. Because OT plays anti-inflammatory and cardioprotective roles and improves vascular and metabolic functions, it demonstrates potential for therapeutic use in various pathologic conditions.

The role of oxytocin in cardiovascular regulation

Studies of body volume expansion have indicated that lesions of the anteroventral third ventricle and median eminence block the release of atrial natriuretic peptide (ANP) into the circulation. Detailed analysis of the lesions showed that activation of oxytocin (OT)-ergic neurons is responsible for ANP release, and it has become clear that activation of neuronal circuitry elicits OT secretion into the circulation, activating atrial OT receptors and ANP release from the heart. Subsequently, we have uncovered the entire functional OT system in the rat and the human heart. An abundance of OT has been observed in the early development of the fetal heart, and the capacity of OT to generate cardiomyocytes (CMs) has been demonstrated in various types of stem cells. OT treatment of mesenchymal stem cells stimulates paracrine factors beneficial for cardioprotection. Cardiovascular actions of OT include: i) lowering blood pressure, ii) negative inotropic and chronotropic effects, iii) parasympathetic neuromodulation, iv) vasodilatation, v) anti-inflammatory activity, vi) antioxidant activity, and vii) metabolic effects. OT actions are mediated by nitric oxide and ANP. The beneficial actions of OT may include the increase in glucose uptake by CMs and stem cells, reduction in CM hypertrophy, oxidative stress, and mitochondrial protection of several cell types. In experimentally induced myocardial infarction in rats, continuous in vivo OT delivery improves cardiac healing and cardiac work, reduces inflammation, and stimulates angiogenesis. Because OT plays anti-inflammatory and cardioprotective roles and improves vascular and metabolic functions, it demonstrates potential for therapeutic use in various pathologic conditions.

Low plasma atrial natriuretic peptide: a new piece in the puzzle of polycystic ovary syndrome.

CONTEXT: It is believed that a dysfunction in adipose tissue plays an important role in the pathogenesis of polycystic ovary syndrome (PCOS). Natriuretic peptides are hormones that regulate cardiovascular and body fluid homeostasis and adipose tissue metabolism. Natriuretic peptide levels are reduced in individuals with obesity and diabetes. OBJECTIVE: This study aimed to investigate whether natriuretic peptide levels are altered in women with PCOS and whether they correlate with adiponectin levels or insulin sensitivity markers. DESIGN AND SETTING: This was a cross-sectional study at a referral center in a teaching hospital. PATIENTS OR OTHER PARTICIPANTS: We evaluated 40 patients diagnosed with PCOS according to the Rotterdam criteria and 36 control women matched for age and body mass index. MAIN OUTCOME MEASURES: We measured serum adiponectin, plasma atrial natriuretic peptide (ANP), and plasma brain natriuretic peptide using enzyme immunoassays in both groups. We evaluated metabolic markers, such as fasting glucose, insulin, total cholesterol, high-density lipoprotein, low-density lipoprotein, and triglycerides. In addition, we calculated the homeostasis model assessment for insulin resistance index (HOMA-IR) and the lipid accumulation product (LAP) index and tested the linear correlations between these metabolic indices and the plasma ANP and serum adiponectin concentrations. RESULTS: ANP and adiponectin were reduced in the PCOS group compared with the control group (P = 0.010 and P = 0.014, respectively). The brain natriuretic peptide concentration did not differ between the two groups (P = 0.883). There was no correlation between ANP and any of the metabolic markers. In the control group, the serum adiponectin level was inversely correlated with BMI (P = 0.011), waist circumference (P = 0.021), insulin (P = 0.013), fasting glucose (P = 0.010), homeostasis model assessment for insulin resistance index (P = 0.007), and lipid accumulation product (P = 0.022). Remarkably, none of these correlations were observed in the women with PCOS. CONCLUSION: Women with PCOS had lower ANP and adiponectin compared with controls matched for age and BMI. Thus, the mechanisms that affect ANP and adiponectin production and clearance may be altered in PCOS, regardless of adiposity. These hormones may be involved in the metabolic features of PCOS.

Assessment of the left atrial volume index and plasma NT-proANP level in patients with acute ST-elevation myocardial infarction.

OBJECTIVES: Acute ST-elevation myocardial infarction is associated with ventricular dysfunction due to ischemia-induced progressive myocardial damage. The decrease in ventricular compliance causes left atrial dilatation and stretching of the atrial myocardium, which are the main stimuli for the secretion of atrial natriuretic peptide. The aim of this study was to evaluate left atrial dimensions and atrial natriuretic peptide levels in patients early after their first acute ST-elevation myocardial infarction and assess the probable interaction between coronary lesions and these measurements. METHODS: A total of 110 patients with acute myocardial infarction and 50 controls were studied. Plasma atrial natriuretic peptide was measured at admission. Left ventricular function, diameter, and volume index were evaluated using transthoracic echocardiography. Gensini and vessel scores of the patients who underwent coronary angiography were calculated. RESULTS: Plasma atrial natriuretic peptide in the patients with myocardial infarction was increased compared with that in controls (3.90±3.75 vs. 1.35±0.72 nmol/L, p<0.001). Although the left atrial diameter was comparable in patients and controls, the left atrial volume index was increased in patients with acute myocardial infarction (26.5±7.1 vs. 21.3±4.9 mL/m2, p<0.01). Multivariate regression analysis showed a strong independent correlation between the left atrial volume index and the plasma atrial natriuretic peptide level (ß=0.23, p=0.03). CONCLUSIONS: The left atrial volume index and plasma atrial natriuretic peptide level were correlated in patients with acute myocardial infarction.

Assessment of the left atrial volume index and plasma NT-proANP level in patients with acute ST-elevation myocardial infarction

OBJECTIVES: Acute ST-elevation myocardial infarction is associated with ventricular dysfunction due to ischemia-induced progressive myocardial damage. The decrease in ventricular compliance causes left atrial dilatation and stretching of the atrial myocardium, which are the main stimuli for the secretion of atrial natriuretic peptide. The aim of this study was to evaluate left atrial dimensions and atrial natriuretic peptide levels in patients early after their first acute ST-elevation myocardial infarction and assess the probable interaction between coronary lesions and these measurements. METHODS: A total of 110 patients with acute myocardial infarction and 50 controls were studied. Plasma atrial natriuretic peptide was measured at admission. Left ventricular function, diameter, and volume index were evaluated using transthoracic echocardiography. Gensini and vessel scores of the patients who underwent coronary angiography were calculated. RESULTS: Plasma atrial natriuretic peptide in the patients with myocardial infarction was increased compared with that in controls (3.90±3.75 vs. 1.35±0.72 nmol/L, p<0.001). Although the left atrial diameter was comparable in patients and controls, the left atrial volume index was increased in patients with acute myocardial infarction (26.5±7.1 vs. 21.3±4.9 mL/m2, p<0.01). Multivariate regression analysis showed a strong independent correlation between the left atrial volume index and the plasma atrial natriuretic peptide level (β = 0.23, p = 0.03). CONCLUSIONS: The left atrial volume index and plasma atrial natriuretic peptide level were correlated in patients with acute myocardial infarction. .

Avaliação do ventrículo direito pelo ecocardiograma com doppler tecidual na embolia pulmonar aguda / Right ventricular assessment by tissue-Doppler echocardiography in acute pulmonary embolism

FUNDAMENTO: A avaliação da função Ventricular Direita (VD) pelo ecocardiograma em pacientes com Tromboembolismo Pulmonar (TEP) é complexa, frequentemente qualitativa; o Doppler tecidual tem sido utilizado para avaliação semiquantitativa dessa câmara, com algumas limitações. OBJETIVO: Avaliar a função do VD no TEP pelo ecocardiograma com Doppler tecidual, complementando com o peptídeo atrial natriurético (BNP). MÉTODOS: Foram estudados pacientes com TEP pelo ecocardiograma com Doppler tecidual e BNP até 24 horas do diagnóstico, obtendo-se as velocidades miocárdicas (s'), strain, strain rate e índice de performance miocárdica do VD; disfunção do VD foi iagnosticada por hipocinesia da câmara, movimento anormal septal e relação VD/VE >1. De acordo com o BNP os pacientes foram divididos em Grupo I, BNP < 50 pg/mL e Grupo II, BNP > 50 pg/mL. RESULTADOS: De 118 pacientes, 100 (60 homens, idade = 55 ± 17 anos) foram analisados; observou-se disfunção do VD em 28%, mais frequentemente no grupo II (19 vs. 9 pacientes, p < 0,001). O grupo II era mais idoso (64 ± 19 vs. 50 ± 15 anos), apresentava menor velocidade de s' (10,5 ± 3,5 vs. 13,2 ± 3,1 cm/s) e maior pressão pulmonar (48 ± 11 vs. 35 ± 11 mmHg), p < 0,001 para todos. O ponto de corte de s' para disfunção do VD foi de 10,8 cm/s (especificidade = 85%, sensibilidade = 54%), com moderada correlação entre o BNP e a onda s'(r = -0,39). CONCLUSÃO: No TEP, a disfunção do VD pelo ecocardiograma se acompanha de elevação do BNP; apesar confirmar adequadamente a presença de disfunção do VD, o Doppler tecidual apresenta sensibilidade limitada para este diagnóstico.

BACKGROUND: Assessment of the right ventricular (RV) function by echocardiography in patients with pulmonary thromboembolism (PTE) is complex and frequently qualitative. Tissue Doppler has been used for the semiquantitative assessment of this chamber, although with some limitations. OBJECTIVE: To evaluate RV function in PTE using tissue-Doppler echocardiography, in addition to atrial natriuretic peptide (BNP). METHODS: Patients with PTE were studied using tissue-Doppler echocardiography and BNP up to 24 hours after diagnosis; myocardial velocities (s'), strain, strain rate and RV myocardial performance index were obtained. RV dysfunction was diagnosed by chamber hypokinesia, abnormal septal motion and a RV/LV ratio >1. According to their BNP levels, the patients were divided into Group I, BNP < 50 pg/mL and Group II, BNP > 50 pg/mL. RESULTS: Of 118 patients, 100 (60 men, age = 55 ± 17 years) were analyzed; RV dysfunction was observed in 28%, more frequently in group II (19 vs. 9 patients, p < 0.001). Patients in group II were older (64 ± 19 vs. 50 ± 15 years), and had lower s' velocity (10.5 ± 3.5 vs. 13.2 ± 3.1 cm/s), and higher pulmonary pressure (48 ± 11 vs. 35 ± 11 mmHg), p < 0.001. The cut-off point of s' for RV dysfunction was 10.8 cm/s (specificity = 85%, sensitivity = 54%), with moderate correlation between BNP and s' wave (r = -0.39). CONCLUSION: In PTE, RV dysfunction on echocardiography is accompanied by BNP elevation; although tissue-Doppler imaging adequately confirms the presence of RV dysfunction, it has a limited sensitivity for this diagnosis.

Right ventricular assessment by tissue-Doppler echocardiography in acute pulmonary embolism.

BACKGROUND: Assessment of the right ventricular (RV) function by echocardiography in patients with pulmonary thromboembolism (PTE) is complex and frequently qualitative. Tissue Doppler has been used for the semiquantitative assessment of this chamber, although with some limitations. OBJECTIVE: To evaluate RV function in PTE using tissue-Doppler echocardiography, in addition to atrial natriuretic peptide (BNP). METHODS: Patients with PTE were studied using tissue-Doppler echocardiography and BNP up to 24 hours after diagnosis; myocardial velocities (s'), strain, strain rate and RV myocardial performance index were obtained. RV dysfunction was diagnosed by chamber hypokinesia, abnormal septal motion and a RV/LV ratio >1. According to their BNP levels, the patients were divided into Group I, BNP < 50 pg/mL and Group II, BNP > 50 pg/mL. RESULTS: Of 118 patients, 100 (60 men, age = 55 ± 17 years) were analyzed; RV dysfunction was observed in 28%, more frequently in group II (19 vs. 9 patients, p < 0.001). Patients in group II were older (64 ± 19 vs. 50 ± 15 years), and had lower s' velocity (10.5 ± 3.5 vs. 13.2 ± 3.1 cm/s), and higher pulmonary pressure (48 ± 11 vs. 35 ± 11 mmHg), p < 0.001. The cut-off point of s' for RV dysfunction was 10.8 cm/s (specificity = 85%, sensitivity = 54%), with moderate correlation between BNP and s' wave (r = -0.39). CONCLUSION: In PTE, RV dysfunction on echocardiography is accompanied by BNP elevation; although tissue-Doppler imaging adequately confirms the presence of RV dysfunction, it has a limited sensitivity for this diagnosis.

Conjugated equine estrogens and estradiol benzoate differentially modulate the natriuretic peptide system in spontaneously hypertensive rats.

OBJECTIVE: The purpose of this study was to compare the effects of conjugated equine estrogens (CEE) and estradiol benzoate on the blood pressure and body weight of spontaneously hypertensive rats (SHRs) and the associated changes in several components of the natriuretic peptide system. METHODS: The blood pressure of randomly distributed female SHRs and Wistar rats was determined by tail plethysmography. The rats were ovariectomized and, after 3 weeks, injected daily for 4 days with estradiol benzoate (5 µg/100 g/d), CEE (50 µg/100 g/d), or vehicle (corn oil 0.1 mL/100 g/d). One day after the last injection, the rats were decapitated, and their blood was collected to measure atrial natriuretic peptide (ANP) and estradiol. The atria were removed to measure ANP levels using radioimmunoassay and to quantify ANP messenger RNA expression using real-time polymerase chain reaction. The kidneys and adipose tissue were removed to analyze the expression of natriuretic peptide clearance receptor messenger RNA. RESULTS: A reduction in blood pressure was observed in estradiol-treated SHRs, but CEE treatment had no effect. Estradiol decreased the body weight and parametrial adipose tissue mass of SHRs. Estradiol-induced alterations in SHRs were accompanied by increased synthesis and release of ANP. CEE had no effect on body weight but increased the mesenteric adipose tissue mass of SHRs. CONCLUSIONS: These results indicate that estradiol and CEE have different effects on the reduction in body weight and blood pressure. These results are correlated with changes in plasma ANP levels.

Tibolone has anti-inflammatory effects in estrogen-deficient female rats on the natriuretic peptide system and TNF-alpha.

Cardiovascular and immune system abnormalities have been reported in females with estrogen deficiency. To control these disorders in post-menopausal women, hormone replacement therapy (HRT) has been used. Tibolone has been used as a HRT, but the effects of tibolone on the natriuretic peptide system have not been determined. We investigated the effects of tibolone on the natriuretic peptide system and pro-inflammatory cytokines in ovariectomized (OVX) rats. Female rats were divided into four groups: SHAM, OVX, OVX treated with 17ß-estradiol (OVX+E: 14 days) and OVX treated with tibolone (OVX+T: 14 days) beginning 21 days after ovariectomy. On day 35, blood was collected to determine atrial natriuretic peptide (ANP), interleukin-6 (IL-6), and tumor necrosis factor-alpha (TNF-α) levels. In addition, tissues were collected for determining ANP, natriuretic peptide receptor type-A (NPR-A), and NPR type-C (NPR-C) gene expression levels by RT-PCR. The cytokine levels of both IL-6 and TNF-α were increased in OVX animals. In comparison, IL-6 and TNF-α levels were reduced in OVX+E animals. TNF-α levels were reduced similarly in OVX+T animals, but IL-6 levels remained elevated in this group. The concentrations of ANP in the left atrium tissue and plasma were decreased after ovariectomy, as were ANP mRNA levels in the left atrium and NPR-A mRNA levels in kidney. No variation in NPR-C gene expression in the kidney tissue was observed among the groups. Tibolone and 17ß-estradiol effectively increased plasma ANP and ANP mRNA levels in the left atrium, but did not normalize renal NPR-A levels. Since HRT with tibolone normalizes plasma ANP and serum TNF-alpha levels our results suggest that treatment with tibolone has anti-inflammatory effects and could prevent cardiovascular disease in the long-term.

Moxonidine into the lateral parabrachial nucleus reduces renal and hormonal responses to cell dehydration.

The deactivation of the inhibitory mechanisms with injections of moxonidine (α2-adrenoceptor/imidazoline receptor agonist) into the lateral parabrachial nucleus (LPBN) increases hypertonic NaCl intake by intra- or extracellular dehydrated rats. In the present study, we investigated the changes in the urinary sodium and volume, sodium balance, and plasma vasopressin and oxytocin in rats treated with intragastric (i.g.) 2 M NaCl load (2 ml/rat) combined with injections of moxonidine into the LPBN. Male Holtzman rats (n=5-12/group) with stainless steel cannulas implanted bilaterally into LPBN were used. Bilateral injections of moxonidine (0.5 nmol/0.2 µl) into the LPBN decreased i.g. 2 M NaCl-induced diuresis (4.6±0.7 vs. vehicle: 7.4±0.6 ml/120 min) and natriuresis (1.65±0.29 vs. vehicle: 2.53±0.17 mEq/120 min), whereas the previous injection of the α2-adrenoceptor antagonist RX 821002 (10 nmol/0.2 µl) into the LPBN abolished the effects of moxonidine. Moxonidine injected into the LPBN reduced i.g. 2 M NaCl-induced increase in plasma oxytocin and vasopressin (14.6±2.8 and 2.2±0.3 vs. vehicle: 25.7±7 and 4.3±0.7 pg/ml, respectively). Moxonidine injected into the LPBN combined with i.g. 2 M NaCl also increased 0.3 M NaCl intake (7.5±1.7 vs. vehicle: 0.5±0.2 mEq/2 h) and produced positive sodium balance (2.3±1.4 vs. vehicle: -1.2±0.4 mEq/2 h) in rats that had access to water and NaCl. The present results show that LPBN α2-adrenoceptor activation reduces renal and hormonal responses to intracellular dehydration and increases sodium and water intake, which facilitates sodium retention and body fluid volume expansion.