A influência da perfusão cardíaca nas relações pressão/volume do ventrículo esquerdo.

PURPOSE--To analyze the influence of the myocardial engorgement due to coronary perfusion on the left ventricular diastolic pressure/volume (P/V) relations. METHODS--The study was undertaken in the isovolumic blood-perfused dog heart preparation (n = 7). The P/V relations were determined promoting ventricular volumes variations by steps of 2ml, in two conditions: during coronary perfusion pressure of 100mmHg and after occlusion of the perfusion line. RESULTS--It was verified that the P/V relations obtained without myocardial perfusion shifted to the down right in respect to the perfused heart. A exponential fitting of the P/V relations allows to conclude that there was no difference among the slopes of the curves obtained with and without perfusion. CONCLUSION--Our results indicated that coronary perfusion restrain the capacity of the left ventricle to receive blood, but there is no influence on the passive elastic stiffness of the chamber. This effect was taught to be consequence of the myocardial erectile property.

Efeito de drogas utilizadas no tratamento de hipertensão arterial sistêmica sobre a pressão intra-ocular: Estudo experimental no cão

Purpose: To study the effects of two drugs (captopril and propranolol) used in the treatment of systemic hypertension, on the intraocular pressure (IOP) of anesthetized dogs. Methods: 24 dogs, divided into 3 groups of 8 each. In the first group, 1.5 mg/kg IV of captopril (an angiotensin converting enzyme inhibitor) was administered. In the second group, 1.5 mg/kg IV of propranolol (a beta-blocker) was administered. The third group was the control. IOP and blood pressure (BP) were measured by manometry. The perfusion pressure was calculated by the difference between BP and IOP (BP-IOP). The parameters were studied at 6 moments (0, 10, 30, 60, 90 and 120 minutes). Results: There was significant reduction of IOP (p<0.05) with captopril and propranolol, without difference between the drugs. With captopril the BP and PP decreased markedly at 10 and 30 minutes. With propranolol there was no reduction of BP or PP. Conclusions: Captopril and propranolol reduced IOP. However, the marked reduction of BP, and consequently of PP caused by captopril may be undesirable for irrigation of the optic nerve.

Efeitos do extrato aquoso de cebola (Allium cepa L.) sobre a função renal e a pressão arterial em ratos Wistar

The vegetal species, Allium cepa, known as onion, is widely used in the folk medicine as diuretic, besides it has been used on the bronchitis, cough, cardiovascular diseases and hypertension treatment. In this study we evaluate the onion aqueous extract (AE) effect on water flow and electrolytes in anesthetized Wistar rats, besides we also evaluate arterial pressure alterations. Two groups were studied: Group 1 (control) - oral tratment with 1.0 mL of distilled water, and Group 2 (experimental) - oral treatment with 1.0 mL of AE 20%. The rats were anesthetized and we canulate the trachea, left carotide artery (for arterial pressure measurement and blood collecting), jugular vein (to execute inulin perfusion - to register glomerular filtration), and urinary bladder (to collect urine). The Group 1 results had shown that the animals had not presented significant alterations (p>0.05) in the analyzed parameters. The animals of Group 2 had a significant reduction (p<0.05) in the arterial pressure (22.0%). However, there were not significant alterations in renal parameters (p>0.05). These results show that the treatment with the AE lead a hypotensor effect in anesthetized Wistar rats, but not followed by renal parameters alterations.

Estudo comparativo dos efeitos hemodinâmicos e ventilatórios da ventilação controlada a volume ou a pressão, em cães submetidos ao pneumoperitônio

BACKGROUND AND OBJECTIVES: Pressure controlled ventilation (PCV) is available in anesthesia machines, but there are no studies on its use during CO 2 pneumoperitoneum (CPP). This study aimed at evaluating pressure-controlled ventilation and hemodynamic and ventilatory changes during CPP, as compared to conventional volume controlled ventilation (VCV). METHODS: This study involved 16 dogs anesthetized with thiopental, fentanyl and pancuronium, which were randomly assigned to two groups: VC - volume controlled ventilation (n=8) and PC - pressure controlled ventilation (n=8). Hemodynamic and ventilatory parameters were monitored and recorded in 4 moments: M1 (before CPP), M2 (30 minutes after CPP = 10 mmHg), M3 (30 minutes after CPP=15 mmHg) and M4 (30 minutes after deflation). RESULTS: With CPP, there has been significant increase in tidal volume in PC group; there has been increase in airway pressures (peak and plateau), decrease in compliance with increase in CPP pressure, increase in heart rate, maintenance of mean blood pressure with higher values in the VC group in all stages; there was also increase in right atrium pressure with significant decrease after deflation, decrease in arterial pH with minor variations in PC group, greater arterial pCO 2 stability in PC group, and no significant changes in arterial pO 2. CONCLUSIONS: There were some differences in hemodynamic and ventilatory data between both ventilation control modes (VC and PC). It is possible to use pressure controlled ventilation during CPP, but the anesthesiologist must monitor and take a close look at alveolar ventilation, adjusting inspiratory pressure to ensure proper CO 2 elimination and oxygenation. © Sociedade Brasileira de Anestesiologia, 2005.

O óxido nítrico (NO) no controle neural da pressão arterial: Modulação da transmissão glutamatérgica no NTS

The neuromodulatory effect of nitric oxide (NO) on glutamatergic transmission within the NTS related to cardiovascular regulation has been widely investigated. Activation of glutamatergic receptors in the NTS stimulates the production and release of NO and other nitrosyl substances with neurotransmitter/neuromodulator properties. The presence of NOS, including the protein nNOS and its mRNA in vagal afferent terminals in the NTS and nodose ganglion cells suggest that NO can act on glutamatergic transmission. We previously reported that iontophoresis of L-NAME on NTS neurons receiving vagal afferent inputs significantly decreased the number of action potentials evoked by iontophoretic application of AMPA. In addition, iontophoresis of the NO donor papaNONOate enhanced spontaneous discharge and the number of action potentials elicited by AMPA, suggesting that NO could be facilitating AMPA-mediated neuronal transmission within the NTS. Furthermore, the changes in renal sympathetic discharge during activation of baroreceptors and cardiopulmonary receptors involve activation of AMPA and NMDA receptors in the NTS and these responses are attenuated by microinjection of L-NAME in the NTS of conscious and anesthetized rats. Cardiovascular responses elicited by application of NO in the NTS are closely similar to those obtained after activation of vagal afferent inputs, and L-glutamate is the main neurotransmitter of vagal afferent fibers. In this review we discuss the possible neuromodulatory mechanisms of central produced/released NO on glutamatergic transmission within the NTS.

Espécies reativas de oxigênio no controle neurovegetativo da pressão arterial

The control of the blood pressure depends on the activity of select groups of neurons present in the central nervous system. Evidence has demonstrated that the redox state (a balance between oxidizing and reducing species) is involved in the control of neuronal activity, which suggests that the redox state can influence the neuronal transmission within the central nervous system acting on the neuronal modulation of biological functions. For instance, the glutamatergic transmission may be widely affected by reactive oxygen species, oxidizing agents that have been extensively investigated due to their involvement in physiological and pathological processes. In the present article, we discuss the main experimental finds that support the hypothesis that reactive oxygen species have important role in physiological (and pathological) modulation of the cardiovascular function through alterations in the sympathetic and parasympathetic system. Therefore, reactive oxygen species can actively participate in the development of cardiovascular diseases like hypertension when the balance in the redox state is disrupted.

Estudo comparativo da pressão arterial sistêmica obtida por dois métodos distintos

As arterial hypertension can be diagnosed by different methods, among which are the traditional auscultatory instrument and the automated oscillometric monitor, the aim of this study was to compare the performance of these instruments, to evaluate the reliability of the digital oscillometer. The sample consisted of 40 patients under dental treatment, whose blood pressure measurements were recorded. The measurements of systolic and diastolic blood pressures were evaluated in terms of their intraclass correlation coefficients (r). For systolic blood pressure, an excellent level of agreement was found between the instruments, with r=0.93, and for diastolic blood pressure, there was a good level of agreement (r=0.75). It was concluded, from the excellent agreement for systolic blood pressure, that the oscillometric monitor can be recommended for the monitoring of the variations of that pressure in the same individual, while the good agreement obtained in the determination of the diastolic blood pressure indicates that the oscillometric method is reliable. However, new studies need to be carried out for a better understanding of the disagreements that can occur in the diastolic pressure results.

Efetividade de um programa de exercícios no condicionamento físico, perfil metabólico e pressão arterial de pacientes hipertensos

Background and objective: It has been shown that aerobic exercise is useful to reduce arterial pressure, however, the effectiveness of an exercise program is still controversial and not very well analyzed among populations with low-income. The objective of the present study was to set up an individualized physical fitness program - Projeto Hipertensão - focused on hypertensive people, patients from a Health Basic Unit (HBU) and, after that, to investigate the effects of this program on physical fitness, metabolic profile and pressure levels. Methods: Sixteen hypertensive women (56 ± 3yrs) under regular pharmacological treatment underwent 4 months of a supervised aerobic and stretching exercise program (3 sessions/wk, 90 min/session, 60% of V̇O 2 max). Several physical and metabolic variables were compared before and after 4 months of training. Results: Training significantly reduced systolic arterial pressure (SAP, -6%), improved cardio-respiratory fitness (+42% of V̇O2max), flexibility (+11%) and plasma glucose content (-4%). BMI and % fat did not change. Besides modifying metabolic profile, it was found that training presented significant correlations between individual initial values of cholesterol total level (CT), high density lipoprotein (HDL-C) and low density lipoprotein (LDL-C) and its responses after exercise. Conclusions: The study shows that exercise programs can be personalized for hypertensive patients from a HBU and confirms the effectiveness of exercise on AP, physical fitness, flexibility and lipid profile on hypertensive patients. The expressive reduction of AP in hypertensive subjects suggests that this exercise intervention should be emphasized on other health centers which assist low-income population.

Edema agudo de pulmão de pressão negativa como complicação grave de síndrome de apneia obstrutiva do sono em crianças. Relatos de casos

Introduction: Obstructive sleep apnea syndrome is related to cardiopulmonary complications in children. It is important to know its patophysiology and possible complications to help reduce risks in this group. Aims: To report three cases of severe cardiorespiratory complications of obstructive sleep apnea managed in the intensive care unit (ICU). Case report: Two children with no previous diagnosis of obstructive sleep apnea syndrome suffered acute congestive heart failure and acute lung oedema with need of ICU and improved after adenotonsillectomy. In a third case, the patient had acute lung oedema as a complication after adenotonsillectomy. Conclusions: Paediatricians and otolaryngologists must be aware of the clinical manifestations of severe sleep apnea. Early referring to treatment and special attention at pre and post surgical periods are essentials to avoid serious complications.

Comparação entre hipertensão autoreferida e pressão arterial casual e presença de fatores de risco em funcionários da saúde Bauru e Jaú

Model: Prevalence study. Objectives: To evaluate the presence of self-reported hypertension to compare with blood pressure measurements. Besides, this work investigated health information level of workers and if the job position has any influence on blood pressure (BP). Methods: This study evaluated 349 health workers (44±10 years old) from Bauru and Jau cities, who answered some questions about history of health condition, use of medicines, past surgeries as well as social, scholar and physical conditions and had their blood pressure measured. Each subject selfreported as normotensive or hypertensive. Values of systolic ≥ 140 mmHg and/or diastolic PA ≥ 90 mmHg were considered elevated. Among the health workers evaluated, 198 were submitted to anthropometric and biochemical evaluations. Values are presented as means ± SD and frequency of distribution. It was used T-student test (p<0.05). Results: From all workers evaluated only 16% self-reported as hypertensive, which 56% presented high BP, however 91% used to take antihypertensive medicines. Among the 84% who self-reported as normotensive, 24% presented high BP and 8% used to take medicines. Although most of the employees of each section self-reported as normotensive, more than a half presented high BP and which was more common in the health's section (76.3%). Conclusion: These results suggest that besides the majority of the employees self-reported as normotensive, an elevated number of health workers presented high blood pressure and used to take medicines inappropriately, which indicates that they did not have enough knowledge about their health. Furthermore, it was observed that Health Section presented the higher blood pressure values.

Úlcera de cameron como causa incomum de anemia por deficiência de ferro

Cameron ulcers are chronic linear lesions willing on the mucosal folds, the level of diaphragmatic impression, in patients with hiatal hernia. Its clinical relevance is due to the potential risk of gastrointestinal complications, such as acute or chronic bleeding and anemia. Usually, the diagnosis is incidental by upper gastrointestinal endoscopy. Proton pump inhibitors are essential for the conduct of cases and the administration of iron when the anemia is associated. Already, the benefit of surgery is in refractory cases. We present a case of this entity of a 50-year-old patient in postmenopausal who developed anemia due to iron deficiency and normal initial endoscopy.

Modelo experimental de úlcera traumática em mucosa jugal de ratos

Purpose: To establish an experimental model of traumatic ulcer in rat cheek mucosa for utilization in future alternative therapy studies. Methods: A total of 60 adult male rats (250 - 300g) were used. Ulceration of the left cheek mucosa was provoked by abrasion using a n o 15 scalpel blade. The animals were observed for 10 days, during which they were weighed and their ulcers were measured. The histological characteristics were analyzed and scored according to the ulcer phase. In the statistical analysis, a value of p<0.01 was considered a statistically significant response in all cases. Results: During the five first days, the animals lost weight (Student t test, p<0.01). The ulcerated area receded linearly over time and was almost completely cicatrized after 10 days (ANOVA, Tendency post-test, p<0.0001). Groups on days 1, 2 and 3 days displayed similar results, but a decrease in scores were observed after the 4th day. Conclusion: The proposed cheek mucosa ulcer model in rats can be considered an efficient, low-cost, reliable, and reproducible method.