Luiz Fernando Junqueira

Comparison of Time‐Domain Short‐Term Heart Interval Variability Analysis Using a Wrist‐Worn Heart Rate Monitor and the Conventional Electrocardiogram

Background: Wrist‐worn heart rate monitors have not been extensively validated for heart rate variability analysis. The purpose of this study was to compare time‐domain variability of heart interval series (R‐Ri) recorded by the Polar S810 monitor (Polar Electro Oy, Kempele, Finland) and the conventional electrocardiogram (ECG).

Cardiac sympathovagal modulation evaluated by short-term heart interval variability is subtly impaired in Alzheimer's disease

Aim:  Alzheimers disease affects several nervous structures involved with the autonomic nervous system. Therefore, the still scarce evaluation of the cardiac autonomic function in this disease is of great functional, clinical, prognostic and therapeutic relevance.

Pentavalent antimonial nephrotoxicity in the rat

Aspects of the renal function were assessed in rats treated with the pentavalent antimonials Glucantime (Meglumine Antimoniate, Rhodia) or Pentostam (Sodium Stibogluconate, Wellcome). In dose of 30 mg of Sbv (Glucantime or Pentostam) by 100 mg of weight by day for 30 days, renal functional changes were observed consisting of disturbances in urine concentrating capacity. Such disturbances were expressed by significantly low values of urine osmolality as compared to the basal values previous to the drugs. The decrease in urine osmolality was associated to a significant increase in urinary flow and in negative free-water clearance. There was no alteration in osmolar clearance and in fractional excretion of sodium. These observations suggest an interference of the drugs in the action of the antidiuretic hormone. The disturbance in urine concentration was reversible after a seven days period without the drugs administration. No significant histopathological alterations were observed in the kidneys of the rats treated with the drugs. On the other hand, the rats treated with a high dose of Pentostam (200 mg/100 grams of weight/day) showed the functional and the histopathological alterations of the acute tubular necrosis.

Função renal em pacientes com leishmaniose muco-cutânea tratados com antimoniais pentavalentes

The renal function in ten patients with mucocutaneous leishmaniasis treated with Glucantime (meglumine antimoniate, Rhodia) or Pentostam (Sodium Stibogluconate, Wellcome) was assessed. During the use of these drugs a defect in concentrating capacity of the kidney was observed expressed as low values of maximun urinary osmolarity and negative maximun clearance of free water in relation to tests made before treatment. The urinary concentrating capacity returned to normal in 5 of the 8 patients studied 15-30 days after the end of treatment. However the maximal urinary osmolarity values where still inferior to those obtained before treatment. In two patients there was a proteinuria above 150 mg/24 hours after antimoniais which disappeared later. The clearance of endogenous creatinine do not alter significatly with the use of these drugs. The results suggest that pentavalent antimoniais can resue in a defect in urine concentrating capacity which is partially reversible after antimonial therapy has ceased.

Risk factors for prolonged hospital stay after isolated coronary artery bypass grafting

INTRODUCTION Characteristics of the patient and the coronary artery bypass grafting may predispose individuals to prolonged hospitalization, increasing costs and morbidity and mortality. OBJECTIVE The objective of this study was to evaluate individual and perioperative risk factors of prolonged hospitalization in intensive care units and wards. METHODS We conducted a case-control study of 104 patients undergoing isolated coronary artery bypass grafting with cardiopulmonary bypass. Patients hospitalized >3 days in the intensive care unit or >7 days in the ward were considered for the study. The association between variables was estimated by the chi-square test, odds ratio and logistic regression; P <0.05 was considered statistically significant. RESULTS Hospital stay >3 days in the intensive care unit occurred for 22.1% of patients and >7 days in the ward for 27.9%. Among preoperative factors, diabetes (OR=3.17) and smoking (OR=4.07) were predictors of prolonged intensive care unit stay. Combining the pre-, intra-and postoperative variables, only mechanical ventilation for more than 24 hours (OR=6.10) was predictive of intensive care unit outcome. For the ward outcome, the preoperative predictor was left ventricular ejection fraction <50% (OR=3.04). Combining pre- and intraoperative factors, diabetes (OR=2.81), and including postoperative factors, presence of infection (OR=4.54) were predictors of prolonged hospitalization in the ward. CONCLUSION Diabetes and smoking were predictors of intensive care unit outcome, and ejection fraction <50% of ward outcome. For the set of perioperative factors, prolonged hospitalization after isolated coronary artery bypass grafting was associated with mechanical ventilation >24 hours for the intensive care unit and presence of infection for the ward.

Digitalis inhibits and furosemide does not change the in vitro phagocytic function of neutrophils of healthy subjects

This work evaluated the in vitro influence of digitalis and furosemide on the phagocytic function of neutrophils of healthy individuals. Phagocytosis of Saccharomyces cerevisiae by peripheral blood neutrophils of 20 healthy individuals was assessed in the absence or presence of deslanoside or furosemide. The Wilcoxon test was employed to compare the data expressed as median and extreme values. Digitalis reduced the number of yeasts ingested by neutrophils (2.23, 1.23-4.01 versus 1.89, 0.87-2.79; p = 0.019). It did not influence the percentage of these cells engaged in phagocytosis, although there was a tendency for reduction (71%, 23-95% versus 57%, 8-93%; p = 0.11), which resulted in decreasing the phagocytic index from 192 (30-381) to 125 (10-218) (p = 0.028). Furosemide had no significant influence on the number of S. cerevisiae phagocytosed (2.23, 1.23-4.01 versus 1.96, 0.70-4.45; p = 0.89), the percent of phagocytosing neutrophils (71%, 23-95% versus 73%, 9-96%; p = 0.86) and the phagocytic index (192, 30-381 versus 152, 10-428; p = 0.95). These findings indicate the inhibitory influence of digitalis on in vitro neutrophil phagocytic function of healthy subjects, and suggest that this effect might impair the innate immune defense response. On this basis, they could contribute to improve digitalis therapy and advise that this drug class should not be associated with other drugs that may also impair the immune function, or might be used with caution or even avoided in subjects with infections.

Agreement between BMI and body fat obesity definitions in a physically active population

Objectives Body mass index (BMI) is a widely used proxy of body composition (BC). Concerns exist regarding possible BMI misclassification among active populations. We compared the prevalence of obesity as categorized by BMI or by skinfold estimates of body fat percentage (BF%) in a physically active population. Subjects and methods 3,822 military firefighters underwent a physical fitness evaluation including cardiorespiratory fitness (CRF) by the 12 min-Cooper test, abdominal strength by sit-up test (SUT) and body composition (BC) by BF% (as the reference), as well as BMI. Obesity was defined by BF% > 25% and BMI ≥ 30 kg/m2. Agreement was evaluated by sensitivity and specificity of BMI, positive and negative predictive values (PPV/NPV), positive and negative likelihood (LR+/LR-), receiver operating characteristic (ROC) curves and also across age, CRF and SUT subgroups. Results The prevalence of obesity estimated by BMI (13.3%) was similar to BF% (15.9%). Overall agreement was high (85.8%) and varied in different subgroups (75.3-94.5%). BMI underestimated the prevalence of obesity in all categories with high specificity (≥ 81.2%) and low sensitivity (≤ 67.0). All indices were affected by CRF, age and SUT, with better sensitivity, NPV and LR- in the less fit and older groups; and higher specificity, PPV and LR+ among the fittest and youngest groups. ROC curves showed high area under the curve (≥ 0.77) except for subjects with CRF ≥ 14 METs (= 0.46). Conclusion Both measures yielded similar obesity prevalences, with high agreement. BMI did not overestimate obesity prevalence. BMI ≥ 30 was highly specific to exclude obesity. Because of systematic under estimation, a lower BMI cut-off point might be considered in this population.

Resting Bradycardia, Enhanced Postexercise Heart Rate Recovery and Cardiorespiratory Fitness in Recreational Ballroom Dancers

ABSTRACT Purpose: In a cross-sectional study design, we evaluated the resting heart rate (HRbaseline) and exercise and postexercise stress test-related chronotropic responses in male practitioners of recreational ballroom dancing (BD; n = 25, Mage = 26.6 ± 6.1 years) compared to a control group of insufficiently active nondancers (CG; n = 25, Mage = 25.9 ± 4.5 years). Method: All participants underwent a submaximal exercise test. At 85% of the maximal predicted HR, the recovery protocol was started, and heart rate recovery (HRR) was recorded during 1-min intervals for 5 min. Results: Compared with CG, BD showed lower HRbaseline (70 beats per minute [bpm] vs. 62 bpm, respectively, U = 143, p < .05, ES = .46), lower preexercise HR (94 bpm vs. 86 bpm, U = 157, p < .05, ES = .42), longer exercise test duration (346 s vs. 420 s, U = 95.5, p < .05, ES = .59), and higher HRR for 5 min postexercise (U = 1.29–1.89, p < .05, ES = .33–.50) as follows: 1st min (32 bpm vs. 40 bpm), 2nd min (45 bpm vs. 53 bpm), 3rd min (51 bpm vs. 58 bpm), 4th min (55 bpm vs. 59 bpm), and 5th min (59 bpm vs. 63 bpm). The coefficient of HRR from the 1st min to the 5th min postexercise was similar in both groups (U = 229–311, p > .05, ES = < .10–.22). Conclusion: Heightened cardiovascular functional status characterized by favorable enhanced chronotropic dynamics appears to occur in practitioners of recreational ballroom dancing, which suggests that this modality of exercise may result in health benefits.

EFEITO DE DIFERENTES PROTOCOLOS DE RECUPERAÇÃO SOBRE A FUNÇÃO AUTONÔMICA CARDÍACA

Introduccion: La evaluacion de la funcion autonomica cardiaca (FAC) despues de la prueba de esfuerzo (PE) se considera un predictor potente e independiente del riesgo cardiovascular. Es escaso el conocimiento de la influencia de los diferentes protocolos de recuperacion sobre la FAC despues de la PE en la cinta rodante con voluntarios en la posicion de pie. Objetivo: Comparar la reactivacion vagal y el grado de la modulacion general de la FAC en dos diferentes protocolos de recuperacion, pasiva (RP) vs. activa (RA) inmediatamente despues de la PE submaxima en la cinta rodante. Metodos: Se evaluaron 24 hombres fisicamente activos con edades (promedio ± DE) de 27,2 ± 4,4 anos y IMC de 24,8 ± 1,8 kg/m2. El orden de los protocolos de recuperacion se definio al azar. Las pruebas se realizaron en un intervalo de siete dias. Ambas recuperaciones se realizaron en la posicion de pie durante cinco minutos inmediatamente despues de la PE. Los indices temporales de la variabilidad de la frecuencia cardiaca fueron utilizados para evaluar la reactivacion vagal y el grado de modulacion general de la FAC, rMSSD y SDNN, respectivamente, en RP y RA. Despues del analisis de la distribucion de los datos, se utilizaron la prueba de Mann-Whitney y la de Friedman con post-hoc de Dum, a un nivel de significacion de p ≤ 0,05. Resultados: Se observo una mayor reactivacion vagal en el primer minuto de la PR comparada a la RA [4,1 (4,9-3,4) ms vs. 3,4 (4,0-2,9) ms, p = 0,03] y un mayor grado de modulacion general de la FAC del tercer al quinto minuto y una tendencia a la diferencia estadistica en el segundo minuto de RP comparada a RA (p = 0,09-0,005). Conclusion: Los resultados muestran que el esfuerzo fisico minimo, como caminar lentamente sobre la cinta rodante, disminuyo la reactivacion vagal y el grado de modulacion general de la FAC despues de la PE submaxima en hombres fisicamente activos.

An Update on Doppler Ultrasound of Vertebral Arteries: Subclavian Steal Syndrome

A sindrome do roubo da subclavia refere-se a uma desordem vascular na qual ocorre inversao do fluxo de sangue da arteria vertebral ipsilateral, decorrente de uma estenose proximal a sua origem, geralmente uma oclusao da arteria subclavia ou, mais raramente, do tronco braquiocefalico. E uma doenca relativamente rara, relatada em aproximadamente 6% dos pacientes assintomaticos com sopros cervicais. O Doppler pulsado (PW) e util na analise da arteria vertebral, registrando informacoes capazes de identificar a presenca da Sindrome do Roubo da Subclavia. Com base nas alteracoes hemodinâmicas da arteria vertebral avaliadas pelo estudo com Doppler espectral, pode ser classificada nos tipos 1 (oculto), 2 (intermitente ou parcial) e 3 (completo). Com o advento da angioplastia transluminal percutânea e, em seguida, dos stents, muitos advogam essa combinacao de procedimentos como o tratamento de escolha dos casos sintomatico dessa sindrome.