Is race adjustment necessary to estimate glomerular filtration rate in South Brazilians?

BACKGROUND AND AIMS: Race coefficients (RC) in equations to estimate glomerular filtration rate (GFR) have been highly questioned. We aimed to evaluate the performance of three equations, namely 2009 Chronic Kidney Disease Epidemiology Collaboration (2009 CKD-EPI), 2021 CKD-EPI, and European Kidney Function Consortium (EKFC) in self-reported Black and White Brazilians. MATERIALS AND METHODS: Our cross-sectional study compared estimated GFR (eGFR) with 51Cr-EDTA measured GFR (mGFR) in healthy adults, patients with type 2 diabetes mellitus with or without chronic kidney disease (CKD), and in non-diabetic individuals with CKD. The performance of these equations was assessed using Bland-Altman plots, Lin's concordance correlation coefficient (CCC), bias, P30, and P15 accuracy. RESULTS: Three hundred six White adults (aged 53 ± 17 years, 55% women, mean mGFR: 83 ± 32 mL/min/1.73 m2) and 48 Black participants (aged 53 ± 17 years, 58% women, mGFR: 90 ± 34 mL/min/1.73 m2) were included. No equation achieved the desirable P30 accuracy value of 90%, neither in White (2009 CKD-EPI:78%, 2021 CKD-EPI:76% and EKFC:77%, p = 0.368) nor in Black volunteers (respective values of 77%, 75%, and 77%; p = 0.882). The 2009 CKD-EPI showed the best performance in Black participants (bias: 4.04; CCC: 0.848), whereas the 2021 CKD-EPI performed better in Whites, with smaller bias (1.45), and better concordance correlation coefficient (0.790). The EKFC presented the worst performance. All equations underdiagnosed advanced CKD in White participants, but not in Black. CONCLUSIONS: The 2021 CKD-EPI does not outperform the 2009 CKD-EPI. Instead, it underestimated the occurrence of CKD in White participants. Thus, we do not recommend replacing the 2009 with the new 2021 CKD-EPI in the Brazilian population.

Isometric handgrip exercise impacts only on very short-term blood pressure variability, but not on short-term blood pressure variability in hypertensive individuals: A randomized controlled trial.

Background: The effect of a single isometric handgrip exercise (IHG) on blood pressure (BP) variability (BPV) has not been addressed. This randomized controlled trial evaluated the effect of IHG vs. sham on BPV and BP. Methods: Hypertensive patients using up to two BP-lowering medications were randomly assigned to IHG (4 × 2 min; 30% of maximal voluntary contraction, MVC, with 1 min rest between sets, unilateral) or sham (protocol; 0.3% of MVC). Systolic and diastolic BP were assessed beat-to-beat in the laboratory before, during, and post-intervention and also using 24-h ambulatory BP monitoring (ABPM). BPV was expressed as average real variability (ARV) and standard deviation (SD). Results: Laboratory BPV, ARV and SD variability, had marked increase during the intervention, but not in the sham group, decreasing in the post-intervention recovery period. The overall change in ARV from pre- to 15 min post-intervention were 0.27 ± 0.07 (IHG) vs. 0.05 ± 0.15 (sham group), with a statistically significant p-value for interaction. Similarly, mean systolic BP increased during the intervention (IHG 165.4 ± 4.5 vs. sham 152.4 ± 3.5 mmHg; p = 0.02) as did diastolic BP (104.0 ± 2.5 vs. 90.5 ± 1.7 mmHg, respectively; p < 0.001) and decreased afterward. However, neither the short-term BPV nor BP assessed by ABPM reached statistically significant differences between groups. Conclusion: A single session of IHG reduces very short-term variability but does not affect short-term variability. IHG promotes PEH in the laboratory, but does not sustain 24-h systolic and diastolic PEH beyond the recovery period.

VALIDITY OF THE INSTRUMENT interRAI EMERGENCY SCREENER FOR PSYCHIATRY FOR THE BRAZILIAN CONTEXT

Objective: The aim of this study was to carry out the translation and present the evidence of validity of the Brazilian version of the interRAI Emergency Screener for Psychiatry (ESP). Method: this is a cross-sectional study conducted in a municipal hospital in the metropolitan region of Porto Alegre, Rio Grande do Sul. A total of 161 patients were evaluated in the first 24 hours of emergency arrival using ESP. Exploratory factor analyses of the sections of the instrument and reliability analyses were conducted using Cronbach's alpha and McDonald's Omega. Results: the analyses suggested an appropriate structure to the purpose of the instrument, two sections containing two factors instead of the expected one-dimensional structure. However, sections with two factors have interpretability and theoretical consistency. The factors presented internal consistency. Conclusion: the Brazilian version of the interRAI Emergency Screener for Psychiatry (ESP) demonstrates adequate psychometric properties through the internal structure of the instrument. Future studies should investigate the relationship of the scores produced by the instrument with clinical diagnosis and with covariates relevant to mental health outcomes.

Objetivo: El objetivo de este estudio era realizar la traducción y presentar la evidencia de validez del examinador de emergencia interRAI para psiquiatría (ESP). Método: se trata de una encuesta transversal realizada en un hospital municipal de la región metropolitana de Porto Alegre, Rio Grande do Sul. Un total de 161 pacientes fueron evaluados en las primeras 24 horas de llegada de emergencia utilizando ESP. Los análisis exploratorios de factores de las secciones del instrumento y los análisis de fiabilidad se llevaron a cabo utilizando Cronbach's alpha y McDonald's Omega. Resultados: los análisis sugirieron una estructura adecuada a los propósitos del instrumento, dos secciones que contienen dos factores en lugar de la estructura unidimensional esperada. Sin embargo, las secciones con dos factores tienen interpretabilidad y consistencia teórica. Los factores presentaron consistencia interna. Conclusión: la versión brasileña del Examinador de Emergencia InterRAI para Psiquiatría (ESP) demuestra propiedades psicométricas adecuadas a través de la estructura interna del instrumento. Los estudios futuros deben investigar la relación de las puntuaciones producidas por el instrumento con el diagnóstico clínico y con covariables relevantes para los resultados de salud mental.

Objetivo: O objetivo do estudo foi realizar a tradução e apresentar as evidências de validade do interRAI Emergency Screener for Psychiatry (ESP). Método: trata-se de uma pesquisa transversal realizada em um hospital municipal da região metropolitana de Porto Alegre, Rio Grande do Sul. Foram avaliados 161 pacientes nas primeiras 24 hs da chegada a emergência utilizando o ESP. Foram conduzidas análises fatoriais exploratórias das seções do instrumento e análises de fidedignidade por meio do alfa de Cronbach e Ômega de McDonald. Resultados: as análises sugeriram uma estrutura adequada ao propósito do instrumento, sendo duas seções contendo dois fatores ao invés da estrutura unidimensional esperada. Contudo, as seções com dois fatores possuem interpretabilidade e consistência teórica. Os fatores apresentaram consistência interna. Conclusão: a versão brasileira do interRAI Emergency Screener for Psychiatry (ESP) demonstra adequadas propriedades psicométricas por meio da estrutura interna do instrumento. Estudos futuros deverão investigar a relação dos escores produzidos pelo instrumento com diagnóstico clínico e com covariáveis relevantes para os desfechos de saúde mental.

Acoustic signal of silent tracheal aspiration in children with oropharyngeal dysphagia.

Objetive: The aim of this study was to characterize the acoustic signal of silent tracheal aspiration in children with oropharyngeal dysphagia (OPD). METHOD: Thirty-two children with OPD were examined with combined digital cervical auscultation (DCA) and videofluoroscopic swallow study (VFSS). Power spectral density (PSD, in 1/√Hz) of the acoustic signal from a sequential series of five liquid swallows was used for comparisons between children who silently aspirated and children who did not aspirate on VFSS. Fourteen children were excluded due to either DCA/VFSS artifact or non-silent aspiration (cough, choking). RESULTS: The remaining 18 participants (median age 6 years, range 2-12.8) were classified based on VFSS as aspirators (n = 8) and non-aspirators (n = 10). The PSD curve of aspirators presented an ascending pattern (1st vs. 5th deglutition: 695.2 vs. 4421.9 1/√Hz), while the curve of non-aspirators was flat (1st vs. 5th deglutition: 509 vs. 463.4 1/√Hz), with marked differences being observed from the 3rd measure onwards (p < .001). In this study, DCA was able to identify silent tracheal aspiration in children with OPD. CONCLUSION: This non-invasive technique identified aspiration by an increase in the PSD curve in aspiration sounds.

Cholinesterase inhibition reduces arrhythmias in asymptomatic Chagas disease.

INTRODUCTION: Parasympathetic dysfunction may play a role in the genesis of arrhythmias in Chagas disease. AIM: This study evaluates the acute effects of pyridostigmine (PYR), a reversible cholinesterase inhibitor, on the occurrence of arrhythmias in patients with Chagas cardiac disease. METHOD: Following a double-blind, randomized, placebo-controlled, cross-over protocol, 17 patients (age 50±2 years) with Chagas cardiac disease type B underwent 24-hour Holter recordings after oral administration of either pyridostigmine bromide (45 mg, 3 times/day) or placebo (PLA). RESULTS: Pyridostigmine reduced the 24-hours incidence (median [25%-75%]) of premature ventricular beats-PLA: 2998 (1920-4870), PYR: 2359 (940-3253), P=.044; ventricular couplets-PLA: 84 (15-159), PYR: 33 (6-94), P=.046. Although the total number of nonsustained ventricular tachycardia in the entire group was not different (P=.19) between PLA (1 [0-8]) and PYR (0 [0-4]), there were fewer episodes under PYR in 72% of the patients presenting this type of arrhythmia (P=.033). CONCLUSION: Acute administration of pyridostigmine reduced the incidence of nonsustained ventricular arrhythmias in patients with Chagas cardiac disease. Further studies that address the use of pyridostigmine by patients with Chagas cardiac disease under a more prolonged follow-up are warranted.

Spontaneous breathing trial in T-tube negatively impact on autonomic modulation of heart rate compared with pressure support in critically ill patients.

INTRODUCTION: Spontaneous breathing with a conventional T-piece (TT) connected to the tracheal tube orotraqueal has been frequently used in clinical setting to weaning of mechanical ventilation (MV), when compared with pressure support ventilation (PSV). However, the acute effects of spontaneous breathing with TT versus PSV on autonomic function assessed through heart rate variability (HRV) have not been fully elucidated. OBJECTIVE: The purpose of this study was to examine the acute effects of spontaneous breathing in TT vs PSV in critically ill patients. METHOD: Twenty-one patients who had received MV for ≥ 48 h and who met the study inclusion criteria for weaning were assessed. Eligible patients were randomized to TT and PSV. Cardiorespiratory responses (respiratory rate -ƒ, tidal volume-VT , mean blood pressure (MBP) and diastolic blood pressure (DBP), end tidal dioxide carbone (PET CO2 ), peripheral oxygen saturation (SpO2 ) and HRV indices in frequency domain (low-LF, high frequency (HF) and LF/HF ratio were evaluated. RESULTS: TT increased ƒ (20 ± 5 vs 25 ± 4 breaths/min, P<0.05), MBP (90 ± 14 vs 94 ± 18 mmHg, P<0.05), HR (90 ± 17 vs 96 ± 12 beats/min, P<0.05), PET CO2 (33 ± 8 vs 48 ± 10 mmHg, P<0.05) and reduced SpO2 (98 ± 1.6 vs 96 ± 1.6%, P<0.05). In addition, LF increased (47 ± 18 vs 38 ± 12 nu, P<0.05) and HF reduced (29 ± 13 vs 32 ± 16 nu, P<0.05), resulting in higher LF/HF ratio (1.62 ± 2 vs 1.18 ± 1, P<0.05) during TT. Conversely, VT increased with PSV (0.58 ± 0.16 vs 0.50 ± 0.15 L, P<0.05) compared with TT. CONCLUSION: Acute effects of TT mode may be closely linked to cardiorespiratory mismatches and cardiac autonomic imbalance in critically ill patients.

Inspiratory muscle training in type 2 diabetes with inspiratory muscle weakness.

PURPOSE: Patients with type 2 diabetes mellitus may present weakness of the inspiratory muscles. We tested the hypothesis that inspiratory muscle training (IMT) could improve inspiratory muscle strength, pulmonary function, functional capacity, and autonomic modulation in patients with type 2 diabetes and weakness of the inspiratory muscles. METHODS: Maximal inspiratory muscle pressure (PImax) was evaluated in a sample of 148 patients with type 2 diabetes. Of these, 25 patients with PImax<70% of predicted were randomized to an 8-wk program of IMT (n=12) or placebo-IMT (n=13). PImax, inspiratory muscle endurance time, pulmonary function, peak oxygen uptake, and HR variability were evaluated before and after intervention. RESULTS: The prevalence of inspiratory muscle weakness was 29%. IMT significantly increased the PImax (118%) and the inspiratory muscle endurance time (495%), with no changes in pulmonary function, functional capacity, or autonomic modulation. There were no significant changes with placebo-IMT. CONCLUSIONS: Patients with type 2 diabetes may frequently present inspiratory muscle weakness. In these patients, IMT improves inspiratory muscle function with no consequences in functional capacity or autonomic modulation.

Acute ingestion of alcohol and cardiac autonomic modulation in healthy volunteers.

Arrhythmogenic effects of alcohol may be intermediated by its effects over heart rate variability (HRV). Most studies about the effects of alcohol over HRV were observational and did not explore the temporal influence of alcohol ingestion over autonomic modulation. The aim of this study was to verify if an acute ingestion of alcohol has a time-dependent influence over time-domain indices of HRV. The effect of the ingestion of 60 g of ethanol or placebo over autonomic modulation was compared in healthy men (35 per group), with 18-25 years of age, before and during 17 h after ingestion. Alcohol promoted a fall in the standard deviation of all normal R-R intervals, root mean square of successive differences, and percentage of pairs of adjacent R-R intervals differing by more than 50 ms and in two indices of the three-dimensional return map, by a period up to 10 h after the ingestion of alcohol, accompanied by an increase in heart rate. The indices returned to values similar of the control group 10 h after ingestion. The effects over HRV indices were attenuated by adjustment for heart rate. The ingestion of alcohol induces a broad cardiovascular adaptation secondary to vagal withdrawal and sympathetic activation that may be responsible for arrhythmogenic effects of alcohol ingestion.

Association between different measurements of blood pressure variability by ABP monitoring and ankle-brachial index.

BACKGROUND: Blood pressure (BP) variability has been associated with cardiovascular outcomes, but there is no consensus about the more effective method to measure it by ambulatory blood pressure monitoring (ABPM). We evaluated the association between three different methods to estimate BP variability by ABPM and the ankle brachial index (ABI). METHODS AND RESULTS: In a cross-sectional study of patients with hypertension, BP variability was estimated by the time rate index (the first derivative of SBP over time), standard deviation (SD) of 24-hour SBP; and coefficient of variability of 24-hour SBP. ABI was measured with a doppler probe. The sample included 425 patients with a mean age of 57 ± 12 years, being 69.2% women, 26.1% current smokers and 22.1% diabetics. Abnormal ABI (≤ 0.90 or ≥ 1.40) was present in 58 patients. The time rate index was 0.516 ± 0.146 mmHg/min in patients with abnormal ABI versus 0.476 ± 0.124 mmHg/min in patients with normal ABI (P = 0.007). In a logistic regression model the time rate index was associated with ABI, regardless of age (OR = 6.9, 95% CI = 1.1- 42.1; P = 0.04). In a multiple linear regression model, adjusting for age, SBP and diabetes, the time rate index was strongly associated with ABI (P < 0.01). None of the other indexes of BP variability were associated with ABI in univariate and multivariate analyses. CONCLUSION: Time rate index is a sensible method to measure BP variability by ABPM. Its performance for risk stratification of patients with hypertension should be explored in longitudinal studies.

Assessment of swallowing sounds by digital cervical auscultation in children.

OBJECTIVES: There is a lack of studies regarding swallowing sounds in children 3 to 11 years of age. This study aimed to assess swallowing sounds by digital cervical auscultation in children of this age group without symptoms of oropharyngeal dysphagia. METHODS: Digital cervical auscultation was performed in 118 subjects by use of a piezoelectric microphone. The children swallowed 5 mL of liquid and yogurt. The components of perceptual acoustic analysis were discrete initial signal (DIS), main signal of swallowing sound (MS), discrete final signal (DFS), and expiratory return (ER). Duration in seconds was the objective parameter of the swallowing sound signal analyzed. RESULTS: Fifty-six boys and 62 girls were evaluated at a mean (+/- SD) age of 6.9 +/- 2.03 years. A complete DIS-MS-DFS-ER swallowing sequence was found in 60% of the children. There was no significant difference in swallowing sound duration between both food consistencies (p = .189) or between genders either for liquid (p = .327) or yogurt (p = .792). There was no correlation between age and duration of the swallowing sound for liquid or yogurt. CONCLUSIONS: We concluded that digital cervical auscultation was able to provide objective information about the swallowing process that could contribute to methodological standardization in children.

Inspiratory muscle training improves blood flow to resting and exercising limbs in patients with chronic heart failure.

OBJECTIVES: We tested the hypothesis that inspiratory muscle loading could result in exaggerated peripheral vasoconstriction in resting and exercising limbs and that inspiratory muscle training (IMT) could attenuate this effect in patients with chronic heart failure (CHF) and inspiratory muscle weakness. BACKGROUND: Inspiratory muscle training improves functional capacity of patients with CHF, but the mechanisms of this effect are unknown. METHODS: Eighteen patients with CHF and inspiratory muscle weakness (maximal inspiratory pressure <70% of predicted) and 10 healthy volunteers participated in the study. Inspiratory muscle loading was induced by the addition of inspiratory resistance of 60% of maximal inspiratory pressure, while blood flow to the resting calf (CBF) and exercising forearm (FBF) were measured by venous occlusion plethysmography. For the patients with CHF, blood flow measurements as well as ultrasound determination of diaphragm thickness were made before and after a 4-week program of IMT. RESULTS: With inspiratory muscle loading, CHF patients demonstrated a more marked reduction in resting CBF and showed an attenuated rise in exercising FBF when compared with control subjects. After 4 weeks of IMT, CHF patients presented hypertrophy of the diaphragm and improved resting CBF and exercise FBF with inspiratory muscle loading. CONCLUSIONS: In patients with CHF and inspiratory muscle weakness, inspiratory muscle loading results in marked reduction of blood flow to resting and exercising limbs. Inspiratory muscle training improves limb blood flow under inspiratory loading in these patients.

Blood lactate during recovery from intense exercise: impact of inspiratory loading.

PURPOSE: It has long been suggested that inspiratory muscle activity may impact blood lactate levels ([Lac(-)]B) during the recovery from dynamic exercise. In this study, we tested the hypothesis that inspiratory muscle activation during recovery from intense exercise would contribute to La clearance, thus leading to reduced [Lac(-)]B. METHODS: Twelve healthy men underwent two maximal, incremental exercise tests on different days. During a 20-min inactive recovery period, they breathed freely or against a fixed inspiratory resistance of 15 cm H2O. During recovery, pulmonary gas exchange was continuously monitored, and serial samples of arterialized venous blood were obtained for [Lac(-)]B, pH, PCO2, and HCO3(-). RESULTS: Subjects presented similar ventilatory and gas-exchange responses at peak exercise during both experimental conditions. [Lac(-)]B during recovery was reduced with inspiratory resistance (7.7 +/- 1 vs 10.4 +/- 1, 7.8 +/- 2 vs 10.3 +/- 2, and 7.3 +/- 1 vs 9.7 +/- 2 mM at 5, 7, and 9 min of recovery, respectively; P < 0.05), but no differences were found for blood acid-base status. Inspiratory resistance was associated with increased metabolic demand (V O2 and V CO2) but improved ventilatory efficiency, with lower V E/[V CO2] and increased alveolar ventilation. CONCLUSION: These data are consistent with the notion that inspiratory muscles may be net consumers of lactate during recovery from intense exercise.

Detection of arteriolar narrowing in fundoscopic examination: evidence of a low performance of direct ophthalmoscopy in comparison with a microdensitometric method.

BACKGROUND: Retinal abnormalities, particularly arteriolar narrowing, are powerful predictors of cardiovascular events. The precision of internists and ophthalmologists in the assessment of retinal vessels widths has been disputed but not evaluated against a technology of edge detection. METHODS: Fifty-two patients with hypertension had optic fundi examination done by an internist and an ophthalmologist, and had retinographies taken and digitized to determine vessel diameters by a new technology of edge detection (microdensitometric method). Physicians asserted the presence of arteriolar narrowing (

Measuring arteriolar-to-venous ratio in retinal photography of patients with hypertension: development and application of a new semi-automated method.

BACKGROUND: The extent of arteriolar narrowing has been recognized as a major sign of end-organ damage in patients with hypertension, but most methods used for its evaluation are highly dependent on the observer. We describe a new semi-automated method to measuring arteriolar-to-venous (A/V) ratio in retinal photography and present its application in the evaluation of patients with hypertension. METHODS: In a cross-sectional study, 58 patients with hypertension had retinographies taken and digitized to determine the vessel diameter by direct measurement (micrometric method) or by the new microdensitometric method. Sub-pixel resolution was obtained via cubic spline fitting of the edge of vessel walls. For each pair of adjacent pixels, 10 intermediate points were generated in the perpendicular direction of the wall. Vessel widths were automatically extracted from this synthetic curve, with cut-points defined where the exterior wall position equals the double of mean noise along the slice. RESULTS: The intra- and interobserver kappa statistics for the diagnosis of abnormal A/V ratio by the microdensitometric measurements were 0.93 (P < .0001) and 0.85 (P = .0005), respectively. Systolic blood pressure was inversely and significantly associated with the A/V ratio measured by the microdensitometric method. CONCLUSIONS: The microdensitometric method is reliable, is easy to operate, and captures the expected association between blood pressure and retinal vessels narrowing. Its performance in clinical practice and in the prediction of cardiovascular events should be confirmed in larger databases with retinographies.

Hormone replacement therapy does not affect the 24-hour heart rate variability in postmenopausal women: results of a randomized, placebo-controlled trial with two regimens.

Postmenopausal women are at greater risk of coronary heart disease. The results of previous studies of the effects of hormone replacement therapy (HRT) on cardiac autonomic modulation in postmenopausal women have been contradictory. This study examined whether continuous treatment for 3 months with estradiol alone (ERT) or with estradiol plus norethisterone (HRT), increases 24-hour heart rate variability (HRV) in postmenopausal women. In this double-blind, placebo-controlled trial, 40 healthy postmenopausal women, 46-63 years of age, were randomly assigned to (1) continuous 2 mg of estradiol plus 1 mg of norethisterone acetate daily (HRT, n = 13), or (2) 2 mg of estradiol daily (ERT, n = 14), or (3) placebo (n = 13). Before and after 3 months of therapy, blood estradiol concentrations were measured and 24-hour electrocardiograms recorded for evaluation of 24-hour time-domain indices of HRV, and indices derived from the three-dimensional return map. Both hormone replacement regimens significantly increased blood estradiol concentrations, while no change occurred in the placebo group. In the three treatment groups, multiple 24-hour time-domain indices of HRV and indices derived from the three-dimensional return map remained unchanged. In healthy postmenopausal women, HRT with estradiol or estradiol and norethisterone for 3 months did not modify cardiac autonomic activity evaluated by 24-hour indices of HRV. These findings are consistent with a lack of protective cardiovascular effect of HRT described in recent large randomized trials.

Hipertensão arterial sistêmica: estudos diagnósticos / Hypertension: diagnostic studies

Confirmação diagnóstica e avaliação de repercussão sobre órgãos-alvo são passos críticos na avaliação de pacientes hipertensos. Demonstramos a importância da aferição repetida da pressão arterial, do tamanho do manguito e da temperatura ambiente para o diagnóstico de hipertensão arterial. Cefaléia tem associação fortuita com pressão arterial, assim como epistaxe. A tradicional classificação de Keith & Wagener (KW) não tem paralelismo com a gravidade da hipertensão arterial. A associação entre anormalidades fundoscópicas isoladas e pressão arterial é fortemente influenciada pela idade dos pacientes. O método microdensitométrico, desenvolvido em nosso serviço em conjunto com a engenharia biomédica, pode aumentar a eficiência da fundoscopia em predizer eventos cardiovasculares. Os achados descritos demonstram a importância de se empregar adequadas rotinas diagnósticas de hipertensão arterial e contribuem para o esclarecimento de muitas falsas associações com hipertensão arterial.

The confirmation of the diagnosis and the evaluation of end-organ damage are indispensable steps in the care of hypertensive patients. Repeated blood pressure measurements, cuff size and room temperature influence the diagnosis of hypertension. Headache and epistaxis have a casual association with blood pressure. The traditional Keith-Wagener (KW) classification does not vary in parallel with the severity of hypertension. The association between isolated funduscopic abnormalities and blood pressure is strongly influenced by age. The microdensitometric method, developed in our service with the collaboration of the bioengineering division, may improve the efficiency of funduscopy in predicting cardiovascular events. These findings confirm the importance of following the recommendations to measure blood pressure and contribute to the understanding of several false associations with hypertension.

Cholinergic stimulation with pyridostigmine reduces ventricular arrhythmia and enhances heart rate variability in heart failure.

BACKGROUND: Increased ventricular arrhythmia density and reduced heart rate variability are associated with risk of death in patients with heart failure. Cholinesterase inhibition with pyridostigmine bromide increases heart rate variability in normal subjects, but its effect on patients with heart failure is unknown. In this study, we tested the hypothesis that short-term administration of pyridostigmine bromide, a cholinesterase inhibitor, reduces ventricular arrhythmia density and increases heart rate variability in patients with congestive heart failure. METHODS: Patients with heart failure and in sinus rhythm participated in a double-blind, cross-over protocol, randomized for placebo and pyridostigmine (30 mg orally 3 times daily for 2 days). Twenty-four hour electrocardiographic recordings were performed for arrhythmia analysis and for the measurement of time domain indices of heart rate variability. Patients were separated into 2 groups, according to their ventricular arrhythmia density. The arrhythmia group (n = 11) included patients with >10 ventricular premature beats (VPBs) per hour (VPBs/h), and the heart rate variability group (n = 12) included patients with a number of VPBs in 24 hours not exceeding 1% of the total number of R-R intervals. RESULTS: For the arrhythmia group, pyridostigmine resulted in a 65% reduction of ventricular ectopic activity (placebo 266 +/- 56 VPBs/h vs pyridostigmine 173 +/- 49 VPBs/h, P =.03). For the heart rate variability group, pyridostigmine administration increased mean R-R interval (placebo 733 +/- 22 ms vs pyridostigmine 790 +/- 33 ms, P =.01), and in the time domain indices of heart rate variability root-mean-square of successive differences (placebo 21 +/- 2 ms vs pyridostigmine 27 +/- 3 ms, P =.01) and percentage of pairs of adjacent R-R intervals differing by >50 ms (placebo 3% +/- 1% vs pyridostigmine 6% +/- 2%, P =.03). CONCLUSION: In patients with heart failure, pyridostigmine reduced ventricular arrhythmia density and increased heart rate variability, most likely due to its cholinomimetic effect. Long-term trials with pyridostigmine in heart failure should be conducted.

Dispositivo para emulação de mouse dedicado a pacientes tetraplégicos ou portadores de doença degenerativa do sistema neuromuscular / Device for emulating of a special cord injurury or with degenerative disease of the neurovascular system

O trabalho descreve o desenvolvimento de um dispositivo que emula um mouse serial Microsoft. Este dispositivo permite ao deficiente físico tetraplégico acessar os recursos de informática em ambiente Windows 95/98 (ler e editar textos, navegar na Internet e utilizar o correio eletrônico) e auxilia o paciente de doenças degenerativas do sistema neuromuscular, como a esclerose lateral amiotrófica (ELA), com disartria, a comunicar-se com as pessoas ao seu redor. O movimento do cursor na tela do computador é produzido a partir do movimento de flexão e extensão da cabeça do usuário, sendo utilizado para medir os ângulos de inclinação um sensor de aceleração estática e dinâmica de dois eixos. Para emular o botão do mouse, são captados os sinais EMG (eletromiográficos) produzidos a partir do movimento voluntário dos músculos mímicos da região frontal do usuário. O processamento digital é realizado por microcontrolador de oito bits e os dados são transmitidos para um computador padrão IBM-PC através da interface RS232C.