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Background and Aims Short daily hemodialysis (SDHD) has improved outcomes observed in conventional thrice-weekly hemodialysis (CHD). Analogously, short daily hemodiafiltration (SDHDF) has also improved outcomes observed in conventional thrice-weekly hemodiafiltration (CHDF). Furthermore, while high-volume CHDF has been proclaimed to be superior to CHD, there have been no studies comparing SDHDF to SDHD. We performed a comparison of clinical, laboratory, echocardiographic and quality of life features in dialysis patients treated by SDHD or SDHDF. Method Twelve patients (mean age 60.8±15.4 years; 7 males; AVF 7, AVG 1, Catheter 4) on regular in-center SDHD program were studied in a longitudinal, prospective, non-randomized, single-subject A-B-A design comparing high-flux SDHD to post-dilution on-line SDHDF. Patients had been for at least 6 months on SDHD (105-150min, 6x/week; SDHD1) and were clinically stable before conversion to SDHDF (105-150min, 6x/week, mean total convective volume of 63.57±5.44 L per week) for 6 months. Following that, all patients were switched back to SDHD for another 6 months (SDHD2). Data were collected at the end of each period. Dialysis parameters throughout the study were matched and set as follows: high-flux polysulfone dialyzers (BBraun Xevonta Hi 23®), blood flow 300–350 mL/min, dialysate flow 500 mL/min and ultra-purified water (Aquaboss heat disinfection osmosis). The results were expressed as mean ± standard deviation. Each patient served as his/her own control. Repeated measures analysis of variance (ANOVA) were used. Results Slightly higher predialysis mean arterial pressure (MAP) levels were observed during SDHDF (102.51±11.28 mmHg) compared to SDHD1 (MAP 95.5±9.82 mmHg, p Conclusion In spite of mild increase of predialysis mean arterial pressure and hemoglobin levels along with greater removal of middle molecular weight solutes, no others clinical, laboratory, echocardiographic or quality of life findings differed significantly during the three periods. Together, these data do not provide evidence of clinically meaningful benefit from on-line hemodiafiltration over high-flux hemodialysis, both performed six times a week.

INTRODUCTION: We investigated the occurrence of coronary sinus abnormalities in the indeterminate form of Chagas disease (CD). METHODS: Differences between the maximum and minimum diameters of the coronary sinus (∆%) on echocardiography were evaluated in individuals with the indeterminate form of CD (n=14) and those without (n=16) CD. The association of the difference with abnormalities detected by echocardiography and myocardial scintigraphy was assessed. RESULTS: The mean Δ% values did not differ significantly between the groups. There was no correlation of the measurements with echocardiographic and myocardial scintigraphy findings. CONCLUSIONS: The coronary sinus evaluation revealed no differences between the groups.

Background: In patients with systemic hypertension, microalbuminuria is a marker of endothelial damage and is associated with an increased risk for cardiovascular disease. Objective: To determine the factors that may lead to the occurrence of microalbuminuria in hypertensive patients with serum creatinine lower than 1.5 mg/dL. Methods: This cross-sectional study included 133 Brazilians with essential hypertension followed up at a hypertension outpatient clinic. Those with serum creatinine higher than 1.5 mg/dL, as well as those with diabetes mellitus, were excluded. Systolic and diastolic blood pressures were measured, and body mass index (BMI) and GFR estimated by using the CKD-EPI formula were calculated. The serum levels of the following were assessed: CysC, creatinine, total cholesterol, HDL cholesterol, LDL cholesterol, triglycerides, C-reactive protein (CRP) and fasting glucose. Microalbuminuria was determined in 24-hour urine. Hypertensive patients were classified according to the presence of one or more criteria for metabolic syndrome. Results: In a multiple regression analysis, the serum levels of CysC and CRP, the atherogenic index log TG/HDLc and the presence of three or more criteria for metabolic syndrome were positively correlated with microalbuminuria (r2: 0.277, p < 0.05). Conclusion: CysC, CRP, log TG/HDLc, and the presence of three or more criteria for metabolic syndrome, regardless of serum creatinine, were associated with microalbuminuria, an early marker of kidney damage and cardiovascular risk in patients with essential hypertension.

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.

FUNDAMENTO: A associação das funções autonômica cardíaca e ventricular sisto-diastólica variavelmente alteradas ainda é controversa e pouco explorada na cardiopatia chagásica crônica. OBJETIVO: Avaliar em que extensão as funções autonômica cardíaca e mecânica ventricular estão alteradas e se ambas estão relacionadas na cardiopatia chagásica assintomática. MÉTODOS: EM 13 cardiopatas chagásicos assintomáticos e 15 indivíduos normais (grupo controle), foram avaliadas e correlacionadas a modulação autonômica da variabilidade da frequência cardíaca durante cinco minutos, nos domínios temporal e espectral, nas posições supina e ortostática, e a função ventricular com base em variáveis morfofuncionais Doppler ecocardiográficas. A análise estatística empregou o teste de Mann-Whitney e a correlação de Spearman. RESULTADOS: Em ambas as posições, os índices temporais (p = 0,0004-0,01) e as áreas espectrais total (p = 0,0007-0,005) e absoluta, de baixa e alta frequências (p = 0,0001-0,002), mostraram-se menores no grupo chagásico. O balanço vagossimpático mostrou-se semelhante em ambas as posturas (p = 0,43-0,89). As variáveis ecocardiográficas não diferiram entre os grupos (p = 0,13-0,82), exceto o diâmetro sistólico final do ventrículo esquerdo que se mostrou maior (p = 0,04), correlacionando-se diretamente com os reduzidos índices da modulação autonômica global (p = 0,01-0,04) e parassimpática (p = 0,002-0,01), nos pacientes chagásicos, em posição ortostática. CONCLUSÃO: AS DEpressões simpática e parassimpática com balanço preservado associaram-se apenas a um indicador de disfunção ventricular. Isso sugere que a disfunção autonômica cardíaca pode preceder e ser independentemente mais severa que a disfunção ventricular, não havendo associação causal entre ambos os distúrbios na cardiopatia chagásica crônica. BACKGROUND: The association of variably altered cardiac autonomic and ventricular systolic and diastolic functions is still controversial and little explored in chronic Chagas' disease. OBJECTIVE: To evaluate the extent to which cardiac autonomic and mechanical ventricular functions are altered and whether they are associated in asymptomatic chagasic cardiomyopathy. METHODS: A total of 13 patients with asymptomatic chagasic cardiomyopathy and 15 normal subjects (control group) were evaluated and the autonomic modulation of heart rate variability for five minutes, in the temporal and spectral domains, in the supine and orthostatic positions, as well as ventricular function based on morphological-functional variables obtained by Doppler echocardiography were correlated. Statistical analysis used the Mann-Whitney test and Spearman's correlation. RESULTS: In both positions, the temporal index (p = 0.0004 to 0.01) and total (p = 0.0007-0.005) and absolute spectral areas, of low and high frequencies (p = 0.0001 to 0.002), were lower in the chagasic group. The vagal-sympathetic balance was similar in both positions (p = 0.43 to 0.89). The echocardiographic variables did not differ between groups (p = 0.13 to 0.82), except the left ventricular end-systolic diameter, which was larger (p = 0.04) and correlated directly with reduced rates of global (p = 0.01 to 0.04) and parasympathetic (p = 0.002 to 0.01) autonomic modulation in patients with Chagas disease in the orthostatic position. CONCLUSION: The sympathetic and parasympathetic depressions with preserved balance were associated with only one ventricular dysfunction indicator. This suggests that cardiac autonomic dysfunction may precede and be independently more severe than ventricular dysfunction, with no causal association between both disorders in chronic chagasic cardiomyopathy.

The association of variably altered cardiac autonomic and ventricular systolic and diastolic functions is still controversial and little explored in chronic Chagas' disease.To evaluate the extent to which cardiac autonomic and mechanical ventricular functions are altered and whether they are associated in asymptomatic chagasic cardiomyopathy.A total of 13 patients with asymptomatic chagasic cardiomyopathy and 15 normal subjects (control group) were evaluated and the autonomic modulation of heart rate variability for five minutes, in the temporal and spectral domains, in the supine and orthostatic positions, as well as ventricular function based on morphological-functional variables obtained by Doppler echocardiography were correlated. Statistical analysis used the Mann-Whitney test and Spearman's correlation.In both positions, the temporal index (p = 0.0004 to 0.01) and total (p = 0.0007-0.005) and absolute spectral areas, of low and high frequencies (p = 0.0001 to 0.002), were lower in the chagasic group. The vagal-sympathetic balance was similar in both positions (p = 0.43 to 0.89). The echocardiographic variables did not differ between groups (p = 0.13 to 0.82), except the left ventricular end-systolic diameter, which was larger (p = 0.04) and correlated directly with reduced rates of global (p = 0.01 to 0.04) and parasympathetic (p = 0.002 to 0.01) autonomic modulation in patients with Chagas disease in the orthostatic position.The sympathetic and parasympathetic depressions with preserved balance were associated with only one ventricular dysfunction indicator. This suggests that cardiac autonomic dysfunction may precede and be independently more severe than ventricular dysfunction, with no causal association between both disorders in chronic chagasic cardiomyopathy.

Background Two-dimensional echocardiography (2D-echo) allows the evaluation of cardiac structures and their movements. A wide range of clinical diagnoses are based on the performance of the left ventricle. The evaluation of myocardial function is typically performed by manual segmentation of the ventricular cavity in a series of dynamic images. This process is laborious and operator dependent. The automatic segmentation of the left ventricle in 4-chamber long-axis images during diastole is troublesome, because of the opening of the mitral valve. Methods This work presents a method for segmentation of the left ventricle in dynamic 2D-echo 4-chamber long-axis images over the complete cardiac cycle. The proposed algorithm is based on classic image processing techniques, including time-averaging and wavelet-based denoising, edge enhancement filtering, morphological operations, homotopy modification, and watershed segmentation. The proposed method is semi-automatic, requiring a single user intervention for identification of the position of the mitral valve in the first temporal frame of the video sequence. Image segmentation is performed on a set of dynamic 2D-echo images collected from an examination covering two consecutive cardiac cycles. Results The proposed method is demonstrated and evaluated on twelve healthy volunteers. The results are quantitatively evaluated using four different metrics, in a comparison with contours manually segmented by a specialist, and with four alternative methods from the literature. The method's intra- and inter-operator variabilities are also evaluated. Conclusions The proposed method allows the automatic construction of the area variation curve of the left ventricle corresponding to a complete cardiac cycle. This may potentially be used for the identification of several clinical parameters, including the area variation fraction. This parameter could potentially be used for evaluating the global systolic function of the left ventricle.

We have recently introduced an algorithm for semi-automatic segmentation of the left ventricular wall in short-axis echocardiographic images (EMBC 30:218-221). In its preprocessing stage, the algorithm uses temporal averaging for image denoising. Motion estimation is used to detect and reject frames that do not correlate well with the set of images being averaged. However, the process of estimating motion vectors is computationally intense, which increases the algorithm's computation time. In this work, we evaluate the viability of replacing the motion estimation stage with less computationally intense approaches. Two alternative techniques are evaluated. The ventricular contours obtained from each of the three algorithm variants were quantitatively and qualitatively compared with contours manually-segmented by a specialist. We show that it is possible to reduce the algorithm's computational load without significantly reducing the segmentation quality. The proposed algorithms are also compared with three other techniques from the literature.

A new left ventricle segmentation method in two-dimensional echocardiography images is proposed. Image processing techniques combined with radial search and temporal information are used to extract the left ventricle boundary. Borders from sequential images are extracted using the proposed method, and a curve illustrating the area variation within a cardiac cycle is presented. Performance evaluation is performed by comparing the borders obtained from the presented method to those manually prescribed by a medical specialist. The new sequential radial search algorithm improved the border extraction from long-axis ultrasound images, specially the ones where the mitral valve was open. Segmentation errors due to low contrast were corrected.

Introduction Cardiac autonomic dysfunction occurs in Chagas' indeterminate and heart disease, but comparison of this disturbance between both forms was not yet performed. Methods Time- and frequency-domain 5-minute heart rate variability in supine and standing positions were evaluated in 17 subjects with Chagas' disease with the indeterminate form, 13 with heart disease and 15 controls. Trend of variability indices across the groups was also tested. Results In the supine position, reduced time-domain and absolute frequency-domain indices reflecting overall autonomic modulation were observed in both Chagas' disease groups. In the standing position, the coefficient of variation and those frequency-domain indices were also reduced, and the other time-domain indices were reduced only in the cardiac group. Heart rate variability indices hypothesized to reflect relative sympathetic and parasympathetic activity showed no alteration. A significant graded reduction was observed in the altered indices in both postures, from the control to the Chagas' indeterminate and heart disease groups. Conclusion Cardiac autonomic dysfunction, with preserved putative measures of sympathetic and parasympathetic modulation in relative terms, was less severe or absent in the indeterminate and pronounced in cardiac form of Chagas' disease.

Two semi-automatic methods for the detection of the left ventricular border in two-dimensional short axis echocardiographic images are presented and compared. In these methods, the left ventricular area variation curve is calculated during a complete cardiac cycle after the segmentation of several frames. This allows the evaluation of the cardiovascular dynamics and the identification of important clinical parameters. The algorithms are proposed as several independent modules. The results are validated through the comparison between the semi-automatic continuous boundaries and manuals boundaries sketched by a medical specialist.