Reproducibility and Reliability Of QTc and QTcd Measurements and Their Relationships with Left Ventricular Hypertrophy in Hemodialysis Patients / Reprodutibilidade e Confiabilidade das Medidas de QTc e DQTc e suas Relações com a Hipertrofia Ventricular Esquerda em Pacientes em Hemodiálise

Abstract Background: Left ventricular hypertrophy (LVH) is very common in hemodialysis patients and an independent risk factor for mortality in this population. The myocardial remodeling underlying the LVH can affect ventricular repolarization causing abnormalities in QT interval. Objective: to evaluate the reproducibility and reliability of measurements of corrected QT interval (QTc) and its dispersion (QTcd) and correlate these parameters with LVH in hemodialysis patients. Methods: Case-control study involving hemodialysis patients and a control group. Clinical examination, blood sampling, transthoracic echocardiogram, and electrocardiogram were performed. Intra- and interobserver correlation and concordance tests were performed by Pearson´s correlation, Cohen's Kappa coefficient and Bland Altman diagram. Linear regression was used to analyze association of QTc or QTcd with HVE. Results: Forty-one HD patients and 37 controls concluded the study. Hemodialysis patients tended to have higher values of QTc, QTcd and left ventricular mass index (LVMi) than controls but statistical significance was not found. Correlation and concordance tests depicted better results for QTc than for QTcd. In HD patients, a poor but significant correlation was found between QTc and LVMi (R2 = 0.12; p = 0.03). No correlation was found between values of QTcd and LVMi (R2= 0.00; p=0.940). For the control group, the correspondent values were R2= 0.00; p = 0.67 and R2= 0.00; p = 0.94, respectively. Conclusion: We found that QTc interval, in contrast to QTcd, is a reproducible and reliable measure and had a weak but positive correlation with LVMi in HD patients.

Resumo Fundamentos: A hipertrofia ventricular esquerda (HVE) é muito comum em pacientes em hemodiálise e um fator de risco independente de mortalidade nessa população. O remodelamento do miocárdio, subjacente à HVE, pode afetar a repolarização ventricular, causando anormalidades no intervalo QT. Objetivo: avaliar a reprodutibilidade e confiabilidade das medidas do intervalo QT corrigido (QTc) e sua dispersão (QTcd), e correlacionar esses parâmetros com HVE em pacientes em hemodiálise. Métodos: Estudo caso-controle envolvendo pacientes em hemodiálise e um grupo controle. Foram realizados avaliação clínica, coleta de sangue, ecocardiografia transtorácica, e eletrocardiograma. Testes de correlação e concordância intraobservador e interobservador foram realizados por correlação de Pearson, coeficiente kappa de Cohen e diagrama de Bland Altman. A regressão linear foi usada para analisar a associação entre QTc ou QTcd e HE. Resultados: Quarenta e um pacientes em hemodiálise e 37 controles completaram o estudo. Houve uma tendência de os pacientes apresentarem valores mais altos de QTc, QTcd e de índice de massa ventricular esquerda que os controles, mas sem significância estatística. Os testes de correlação e de concordância apresentaram melhores resultados para QTc que para QTcd. Em pacientes em hemodiálise, uma correlação fraca, mas significativa foi encontrada entre QTc e IMVE (R2 = 0,12; p = 0,03). Não foi encontrada correlação entre QTcd e IMVE (R2 = 0,00; p=0,940). Para o grupo controle, esses valores correspondentes foram R2 = 0,00; p = 0,67 e R2 = 0,00; p = 0,94, respectivamente. Conclusão: o intervalo QTc, diferentemente do intervalo QTcd, é uma medida reprodutível e confiável, e apresentou uma correlação fraca, mas positiva com o IMVE em pacientes em hemodiálise.

Reproducibility and Reliability Of QTc and QTcd Measurements and Their Relationships with Left Ventricular Hypertrophy in Hemodialysis Patients.

BACKGROUND: Left ventricular hypertrophy (LVH) is very common in hemodialysis patients and an independent risk factor for mortality in this population. The myocardial remodeling underlying the LVH can affect ventricular repolarization causing abnormalities in QT interval. OBJECTIVE: to evaluate the reproducibility and reliability of measurements of corrected QT interval (QTc) and its dispersion (QTcd) and correlate these parameters with LVH in hemodialysis patients. METHODS: Case-control study involving hemodialysis patients and a control group. Clinical examination, blood sampling, transthoracic echocardiogram, and electrocardiogram were performed. Intra- and interobserver correlation and concordance tests were performed by Pearson´s correlation, Cohen's Kappa coefficient and Bland Altman diagram. Linear regression was used to analyze association of QTc or QTcd with HVE. RESULTS: Forty-one HD patients and 37 controls concluded the study. Hemodialysis patients tended to have higher values of QTc, QTcd and left ventricular mass index (LVMi) than controls but statistical significance was not found. Correlation and concordance tests depicted better results for QTc than for QTcd. In HD patients, a poor but significant correlation was found between QTc and LVMi (R2 = 0.12; p = 0.03). No correlation was found between values of QTcd and LVMi (R2= 0.00; p=0.940). For the control group, the correspondent values were R2= 0.00; p = 0.67 and R2= 0.00; p = 0.94, respectively. CONCLUSION: We found that QTc interval, in contrast to QTcd, is a reproducible and reliable measure and had a weak but positive correlation with LVMi in HD patients.

Long-Term Effects of Renal Sympathetic Denervation on Hypertensive Patients With Mild to Moderate Chronic Kidney Disease.

Thirty patients who underwent percutaneous renal denervation, which was performed by a single operator following the standard technique, were enrolled in this study. Patients with chronic kidney disease (CKD) stage 2 (n=19), 3 (n=6), and 4 (n=5) were included. Data were obtained at baseline and at monthly intervals for the first 6 months. At 7 months, follow-up data were collected bimonthly until month 12, after which data were collected on a quarterly basis. Baseline blood pressure values (mean±standard deviation) were 185±18/107±13 mm Hg in the office and 152±17/93±11 mm Hg through 24-hour ambulatory blood pressure monitoring (ABPM). Three patients with stage 4 CKD required chronic renal replacement therapy (one at the 13-month follow-up and two at the 14-month follow-up) after episodes of acute renal injury; their follow-up was subsequently discontinued. The office blood pressure values at the 24-month follow-up were 131±15/87±9 mm Hg (P<.0001, for both comparisons); the corresponding ABPM values were 132±14/84±12 mm Hg (P<.0001, for both comparisons). The mean estimated glomerular filtration rate increased from 61.9±23.9 mL/min/1.73 m(2) to 88.0±39.8 mL/min/1.73 m(2) (P<.0001). The urine albumin:creatinine ratio decreased from 99.8 mg/g (interquartile range, 38.0-192.1) to 11.0 mg/g (interquartile range, 4.1-28.1; P<.0001 mg/g). At the end of the follow-up period, 21 patients (70% of the initial sample) were no longer classified as having CKD.

Heart Rate Variability Correlates to Functional Aerobic Impairment in Hemodialysis Patients.

BACKGROUND: Autonomic dysfunction (AD) is highly prevalent in hemodialysis (HD) patients and has been implicated in their increased risk of cardiovascular mortality. OBJECTIVE: To correlate heart rate variability (HRV) during exercise treadmill test (ETT) with the values obtained when measuring functional aerobic impairment (FAI) in HD patients and controls. METHODS: Cross-sectional study involving HD patients and a control group. Clinical examination, blood sampling, transthoracic echocardiogram, 24-hour Holter, and ETT were performed. A symptom-limited ramp treadmill protocol with active recovery was employed. Heart rate variability was evaluated in time domain at exercise and recovery periods. RESULTS: Forty-one HD patients and 41 controls concluded the study. HD patients had higher FAI and lower HRV than controls (p<0.001 for both). A correlation was found between exercise HRV (SDNN) and FAI in both groups. This association was independent of age, sex, smoking, body mass index, diabetes, and clonidine or beta-blocker use, but not of hemoglobin levels. CONCLUSION: No association was found between FAI and HRV on 24-hour Holter or at the recovery period of ETT. Of note, exercise HRV was inversely correlated with FAI in HD patients and controls.

Heart Rate Variability Correlates to Functional Aerobic Impairment in Hemodialysis Patients / Variabilidade RR ao Esforço Correlaciona-se com Déficit Funcional Aeróbico em Pacientes em Hemodiálise

Background: Autonomic dysfunction (AD) is highly prevalent in hemodialysis (HD) patients and has been implicated in their increased risk of cardiovascular mortality. Objective: To correlate heart rate variability (HRV) during exercise treadmill test (ETT) with the values obtained when measuring functional aerobic impairment (FAI) in HD patients and controls. Methods: Cross-sectional study involving HD patients and a control group. Clinical examination, blood sampling, transthoracic echocardiogram, 24-hour Holter, and ETT were performed. A symptom-limited ramp treadmill protocol with active recovery was employed. Heart rate variability was evaluated in time domain at exercise and recovery periods. Results: Forty-one HD patients and 41 controls concluded the study. HD patients had higher FAI and lower HRV than controls (p<0.001 for both). A correlation was found between exercise HRV (SDNN) and FAI in both groups. This association was independent of age, sex, smoking, body mass index, diabetes, and clonidine or beta-blocker use, but not of hemoglobin levels. Conclusion: No association was found between FAI and HRV on 24-hour Holter or at the recovery period of ETT. Of note, exercise HRV was inversely correlated with FAI in HD patients and controls. (Arq Bras Cardiol. 2015; [online]. ahead print, PP.0-0) .

Fundamento: A disfunção autonômica (DA) é altamente prevalente em pacientes em hemodiálise (HD) e tem sido implicada no risco aumentado de mortalidade cardiovascular. Objetivo: Correlacionar a variabilidade RR (VRR) durante o teste ergométrico (TE) com o déficit funcional aeróbico (FAI) em pacientes em HD e em um grupo controle. Métodos: Trata-se de um estudo transversal no qual as variáveis analisadas foram obtidas através de exame clínico, coleta de sangue, ecocardiograma transtorácico, Holter de 24 horas e TE. Foi realizado TE em esteira pelo protocolo de rampa, limitado por sintomas, com recuperação ativa. A VRR foi avaliada no domínio do tempo no exercício e na recuperação separadamente. Resultados: Quarenta e um pacientes em HD e 41 controles concluíram o estudo. Pacientes em HD tinham maior FAI e menor VRR do que os controles (p <0,001 para ambos). Houve correlação entre FAI e VRR no exercício (SDNN) em ambos os grupos. Esta associação foi independente de idade, sexo, tabagismo, índice de massa corporal, diabetes, clonidina, betabloqueador, mas não dos níveis de hemoglobina. Conclusão: A VRR no exercício foi inversamente correlacionada com o FAI em pacientes em HD e controles. Não foram observadas associações do FAI com VRR no Holter ou no período de recuperação do TE. .

Renal sympathetic denervation in patients with hypertension and chronic kidney disease: does improvement in renal function follow blood pressure control?

Twenty-seven patients with resistant hypertension and chronic kidney disease were treated by renal sympathetic denervation (RSD) and followed for 12 months. Patients were retrospectively divided into controlled and uncontrolled blood pressure (BP) groups. Increases in mean estimated glomerular filtration rate (eGFR) were found at months 1, 3, 6, and 12 in the controlled group (P < .0001, for every time point). The mean change in eGFR after 12 months was 18.54 ± 8.15 mL/min/1.73 m(2) higher in the controlled group (P=.0318). In patients in the controlled group with baseline eGFR < 45 mL/min/1.73 m(2), responders (with an increase in eGFR > 6.2%) corresponded to 50% at 6 months and 83% at 12 months. In the patients with baseline eGFR ≥ 45 mL/min/1.73 m(2), all patients were labeled as responders at months 6 and 12. Median albumin:creatinine ratio after 12 months was lower than baseline only in the controlled group (P = .0003). Our results suggest that patients with this profile who reached BP control by RSD also experienced a significant improvement in renal function.

Anormalidades no descenso da frequência cardíaca ao teste ergométrico em diabéticos / Heart rate decline anomalies during treadmil tests for diabetics

Fundamentos: Estudos demonstraram que a disfunção autonômica cardiovascular, medida através da variabilidade da frequência cardíaca, está associada a aumento do risco cardiovascular. Objetivos: Comparar a presença de disautonomia em diabéticos e não diabéticos através do teste ergométrico e determinar as variáveis preditoras de disautonomia em diabéticos. Métodos: Estudo retrospectivo, com pacientes que realizaram o teste ergométrico em caráter eletivo sob protocolo individualizado de rampa. Os pacientes foram estratificados em dois grupos: diabéticos (G1) e não diabéticos (G2). Foram definidos como disautonômicos os pacientes que obtiveram uma redução da FC no primeiro minuto da recuperação <12bpm. Os grupos G1 e G2 foram comparados. As variáveis com valores de p≤0,10 foram submetidas à análise de regressão logística. Resultados: Foram avaliados 1433 pacientes submetidos ao TE. A idade média foi 52,65±13,06 anos e variou entre 18-92 anos. Observaram-se, no G1, indivíduos mais velhos, obesos e dislipidêmicos. No teste ergométrico houve diferenças na FCR no primeiro minuto, FC do picodo esforço, número de METs e déficit cronotrópico. Submetidas as variáveis da população amostral, diabéticos e não diabéticos, à regressão logística, encontrou-se um único preditor de disautonomia: o número de METs (IC95% 0,083/0,031; p<0,0001); nos diabéticos, o único preditor independente da presença de disautonomia foi o índice de massa corporal (IC95%0,002-0,025; p=0,02). Conclusão: Indivídos diabéticos apresentam recuperação mais lenta da FC no pós-esforço que não diabéticos, evidenciando maior disautonomia e menor capacidade física; os diabéticos com excesso de peso têm maior comprometimento do sistema autonômico.

Sintomas depressivos e hospitalizações por insuficiência cardíaca: prevalência, preditores e mortalidade / Depressive symptoms and hospitalizations for heart failure: prevalence, predictors and mortality

Fundamentos. Estudos sobre sintomas depressivos (SD) têm sido feitos em pacientes hospitalizados por insuficiência cardíaca (IC) e tem sido ignorada a influência de várias características. Objetivos. Avaliar prevalência, preditores e correlação da gravidade dos SD e a mortalidade em hospitalizações por IC. Métodos. Estudo prospectivo que analisou hospitalizações consecutivas por IC. Foram analisados dados sociodemográficos, clínicos e o desfecho considerado foi óbito. Na análise dos SD foi utilizado o Inventário de Depressão de Beck. Foi feita análise comparativa entre grupos com e sem SD e submetidos a regressão logística as variáveis com p entre 0,05 e 0,1. Avaliou-se a relação entre a gravidade de SD e mortalidade. Foi utilizado teste qui-quadrado ou exato de Fisher para variáveis categóricas e t de student para contínuas. Foi considerado estatisticamente significante p<0,05. Resultados. Foram avaliados 103 pacientes, sendo 63,1% mulheres, 50,5% casados e alfabetizados 73,8%. O total de 75,2% estava em classe funcional II e III de New York Heart Association (NYHA). Hipertensão arterial sistêmica foi a comorbidade mais comum (92,2%). A presença de SD foi presente em 69 (67%) pacientes. Os preditores de SD foram: estado civil (p=0,03) e na regressão logística: sexo (p<0,0001), modo de vida (0,002) e etiologia da IC (p<0,0001). A mortalidade relacionou-se à SD em sintomas moderados (p=0,04) e graves (0,01). Conclusão. Os SD são comuns em hospitalizações por IC. A prevalência varia conforme características clínicas dos pacientes. Os preditores foram sexo, estado civil, modo de vida e etiologia da IC. A mortalidade relacionouse a SD moderados e graves.

Background. Studies of depressive symptoms (DS) has been made in patients hospitalized for heart failure (HF) and the influence of various characteristics has been ignored. Objectives. To assess prevalence, predictors and correlated to the severity of DS and mortality in HF hospitalizations. Methods. This prospective study examined consecutive hospitalizations for HF. We analyzed sociodemographic data and clinical outcome was death. In analysis of DS was used Beck Depression Inventory II. Comparative analysis were made between groups with and without DS and subjected to logistic regression variables with p between 0.05 and 0.1. We evaluated the relationship between the severity of SD and mortality. It was considered statistically significant p <0.05. Results: We evaluated 103 patients, 63.1% women, 50.5% were married and 73.8% literate. A total of 75.2% were in New York Heart Association (NYHA) functional class II and III. Hypertension was the most common comorbidity (92.2%). The DS was present in 69 (67%) patients. The predictors of DS were: marital status (p=0.03) and logistic regression: sex (p<0.0001), lifestyle (0.002) and etiology of HF (p<0.0001). Mortality was related to the DS in moderate symptoms (p=0.04) and severe (0.01). Conclusion. The DS are common in HF hospitalizations. The prevalence varies according to clinical characteristics of patients. The predictors were gender, marital status, lifestyle and etiology of HF. Mortality was related to moderate and severe DS.

Avaliação da disautonomia nos pacientes com insuficiênia cardíaca através de teste de esforço: [revisão] / Stress test evaluation of dysautonomia in heart failure patients: [review]

O teste de esforço é um método não invasivo de grande aplicabilidade clínica na cardiologia. Seu uso, atualmente, não mais se limita ao diagnóstico de doença arterial coronariana devido à grande variedade de informações que o teste revela. A associação de alterações clínicas, hemodinâmicas e metabólicas com as alterações eletrocardiográficas ampliaram o poder não só diagnóstico, mas, especialmente o poder prognóstico do método. Mais recentemente, a avaliação do comportamento do sistema nervoso autonômico, durante o exercício dinâmico, tem mostrado grande valor em cardiopatias graves, como na insuficiência cardíaca. O objetivo desta revisão é descrever como os novos parâmetros do teste de esforço podem ser utilizados para avaliar o sistema nervoso autonômico em pacientes com insuficiência cardíaca e descrever suas implicações prognósticas.

A non-invasive method with ample clinicalapplication in cardiology, stress testing is no longer limited to diagnosing coronary artery disease, due to the broad range of information that it provides. Associating changes in clinical, metabolic and hemodynamic responses with electrocardiographic alterations has extended its diagnostic and prognosticcapacities. More recently, evaluating the behavior of the autonomic nervous system during dynamic exercise has proven extremely valuable for severecardiovascular diseases, such as heart failure. This paper describes how new stress test parameters may be deployed to evaluate the autonomic nervoussystem in heart failure patients, in addition to describing its prognostic implications.

Resposta da pressäo arterial ao esforço máximo em hipertensos sob diferentes esquemas terapêuticos / Response of blood pressure to maximum exercise in hypertensive patients under different therapeutic programs

OBJECTIVE: To evaluate the behavior of blood pressure during exercise in patients with hypertension controlled by frontline antihypertension drugs. METHODS: From 979ergometric tests we retrospectively selected 49 hipertensive patients (19 males). The age was 53+/-12 years old and normal range rest arterial pressure (<=140/90 mmHg) all on pharmacological monotherapy. There were 12 on beta blockers; 14 on calcium antagonists, 13 on diuretics and 10 on angiotensin converting enzyme inhibitor. Abnormal exercise behhavior of blood pressure was diagnosed if anyone of the following criteria was detected: peak systolic pressure above 220 mmHg, raising of systolic pressure > or = 10 mmHg/MET; or increase of diastolic pressure greater than 15 mmHg. RESULTS: Physiologic response of arterial blood pressure occurred in 50 percent of patients on beta blockers, the best one (p<0.05), in 36 percent and 31 percent on calcium antagonists and on diuretics, respectively, and in 20 percent on angiotensin converting enzyme inhibitor, the later the leastr one (p<0.05). CONCLUSION: Beta-blockers were more effective than calcium antagonists, diuretics and angiotensin-converting enzyme inhibitors in controlling blood pressure during exercise, and angiotensin converting enzyme inhibitors the least effective drugs

Teste esforço em hipertensos em uso de inibidores da enzima conversora da angiotensiva de tempo de ação curto e prolongado / Test effort in hypertensive patients taking angiotensin-converting angiotensiva time action short and long

Fundamento: Os inibidores da enzima conversora da angiotensina (ECA) são anti-hipertensivos eficientes no controle da pressão arterial (PA) em repouso. Entretanto, não está bem estabelecido se inibidores da ECA de tempo de ação curto ou prolongado determinam diferentes respostas da PA ao esforço...Conclusões: Os resultados sugerem que o trandolapril, IECA de ação prolongada é mais eficiente no controle da pressão arterial durante o exercício e na redução da PA após o exercício que o captopril. IECA de ação curta. O aumento da tolerância ao esforço, maior após o uso de trandolapril (+31%) que de captopril (+17%; p=0,01), provavelmente decorreu da menor incidência de interrupção do TE por níveis elevados de PA (interrupção/PA alta) no grupo T