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ECG Multilead QT Interval Estimation Using Support Vector Machines. JOURNAL OF HEALTHCARE ENGINEERING 2019; 2019:6371871. [PMID: 31178988 PMCID: PMC6501152 DOI: 10.1155/2019/6371871] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/31/2018] [Revised: 01/27/2019] [Accepted: 02/12/2019] [Indexed: 01/01/2023]
Abstract
This work reports a multilead QT interval measurement algorithm for a high-resolution digital electrocardiograph. The software enables off-line ECG processing including QRS detection as well as an accurate multilead QT interval detection algorithm using support vector machines (SVMs). Two fiducial points (Qini and Tend) are estimated using the SVM algorithm on each incoming beat. This enables segmentation of the current beat for obtaining the P, QRS, and T waves. The QT interval is estimated by updating the QT interval on each lead, considering shifting techniques with respect to a valid beat template. The validation of the QT interval measurement algorithm is attained using the Physionet PTB diagnostic ECG database showing a percent error of 2.60 ± 2.25 msec with respect to the database annotations. The usefulness of this software tool is also tested by considering the analysis of the ECG signals for a group of 60 patients acquired using our digital electrocardiograph. In this case, the validation is performed by comparing the estimated QT interval with respect to the estimation obtained using the Cardiosoft software providing a percent error of 2.49 ± 1.99 msec.
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Martí‐Carvajal AJ, Kwong JSW. Pharmacological interventions for treating heart failure in patients with Chagas cardiomyopathy. Cochrane Database Syst Rev 2016; 7:CD009077. [PMID: 27388039 PMCID: PMC6457883 DOI: 10.1002/14651858.cd009077.pub3] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
BACKGROUND Chagas disease-related cardiomyopathy is a major cause of morbidity and mortality in Latin America. Despite the substantial burden to the healthcare system, there is uncertainty regarding the efficacy and safety of pharmacological interventions for treating heart failure in people with Chagas disease. This is an update of a Cochrane review published in 2012. OBJECTIVES To assess the clinical benefits and harms of current pharmacological interventions for treating heart failure in people with Chagas cardiomyopathy. SEARCH METHODS We updated the searches in the Cochrane Central Register of Controlled Trials (CENTRAL; The Cochrane Library 2016, Issue 1), MEDLINE (Ovid; 1946 to to February Week 1 2016), EMBASE (Ovid; 1947 to 2016 Week 07), LILACS (1982 to 15 February 2016), and Web of Science (Thomson Reuters; 1970 to 15 February 2016). We checked the reference lists of included papers. We applied no language restrictions. SELECTION CRITERIA We included randomised clinical trials (RCTs) that assessed the effects of pharmacological interventions to treat heart failure in adult patients (18 years or older) with symptomatic heart failure (New York Heart Association classes II to IV), regardless of the left ventricular ejection fraction stage (reduced or preserved), with Chagas cardiomyopathy. We did not apply limits to the length of follow-up. Primary outcomes were all-cause mortality, cardiovascular mortality at 30 days, time-to-heart decompensation, disease-free period (at 30, 60, and 90 days), and adverse events. DATA COLLECTION AND ANALYSIS Two authors independently performed study selection, 'Risk of bias' assessment and data extraction. We estimated relative risk (RR) and 95% confidence intervals (CIs) for dichotomous outcomes. We measured statistical heterogeneity using the I² statistic. We used a fixed-effect model to synthesize the findings. We contacted authors for additional data. We developed 'Summary of findings' (SoF) tables and used GRADE methodology to assess the quality of the evidence. MAIN RESULTS In this update, we identified one new trial. Therefore, this version includes three trials (108 participants). Two trials compared carvedilol against placebo and another assessed rosuvastatin versus placebo. All trials had a high risk of bias.Meta-analysis of two trials showed a lower proportion of all-cause mortality in the carvedilol groups compared with the placebo groups (RR 0.69; 95% CI 0.12 to 3.88, I² = 0%; 69 participants; very low-quality evidence). Neither of the trials reported on cardiovascular mortality, time-to-heart decompensation, or disease-free periods.One trial (30 participants) found no difference in hospital readmissions (RR 1.00; 95% CI 0.31 to 3.28; very low-quality of evidence) or reported adverse events (RR 0.92; 95% CI 0.67 to 1.27; very low-quality of evidence) between the carvedilol and placebo groups.There was very low-quality evidence from two trials of inconclusive effects on quality of life (QoL) between the carvedilol and placebo groups. One trial (30 participants) assessed QoL with the Minnesota Living With Heart Failure Questionnaire (21 items; item scores range from 0 to 5; a lower MLHFQ score is better). The MD was -14.74; 95% CI -24.75 to -4.73. The other trial (39 participants) measured QoL with the Medical Outcomes Study 36-item short-form health survey (SF-36; item scores range from 0 to 100; higher SF-36 score is better). Data were not provided.One trial (39 participants) assessed the effect of rosuvastatin versus placebo. The trial did not report on any primary outcomes or adverse events. There was very low-quality evidence of uncertain effects on QoL (no data were provided). AUTHORS' CONCLUSIONS This first update of our review found very low-quality evidence for the effects of either carvedilol or rosuvastatin, compared with placebo, for treating heart failure in people with Chagas disease. The three included trials were underpowered and had a high risk of bias. There were no conclusive data to support or reject the use of either carvedilol or rosuvastatin for treating Chagas cardiomyopathy. Unless randomised clinical trials provide evidence of a treatment effect, and the trade-off between potential benefits and harms is established, policy-makers, clinicians, and academics should be cautious when recommending or administering either carvedilol or rosuvastatin to treat heart failure in people with Chagas disease. The efficacy and safety of other pharmacological interventions for treating heart failure in people with Chagas disease remains unknown.
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Affiliation(s)
| | - Joey SW Kwong
- West China Hospital, Sichuan UniversityChinese Evidence‐Based Medicine CenterNo. 37, Guo Xue XiangChengduSichuanChina610041
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3
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Cardiac sympathetic denervation for intractable ventricular arrhythmias in Chagas disease. Heart Rhythm 2016; 13:1388-94. [DOI: 10.1016/j.hrthm.2016.03.014] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/08/2015] [Indexed: 11/23/2022]
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Morrot A, Villar SR, González FB, Pérez AR. Evasion and Immuno-Endocrine Regulation in Parasite Infection: Two Sides of the Same Coin in Chagas Disease? Front Microbiol 2016; 7:704. [PMID: 27242726 PMCID: PMC4876113 DOI: 10.3389/fmicb.2016.00704] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2015] [Accepted: 04/28/2016] [Indexed: 12/16/2022] Open
Abstract
Chagas disease is a serious illness caused by the protozoan parasite Trypanosoma cruzi. Nearly 30% of chronically infected people develop cardiac, digestive, or mixed alterations, suggesting a broad range of host-parasite interactions that finally impact upon chronic disease outcome. The ability of T. cruzi to persist and cause pathology seems to depend on diverse factors like T. cruzi strains, the infective load and the route of infection, presence of virulence factors, the parasite capacity to avoid protective immune response, the strength and type of host defense mechanisms and the genetic background of the host. The host-parasite interaction is subject to a constant neuro-endocrine regulation that is thought to influence the adaptive immune system, and as the infection proceeds it can lead to a broad range of outcomes, ranging from pathogen elimination to its continued persistence in the host. In this context, T. cruzi evasion strategies and host defense mechanisms can be envisioned as two sides of the same coin, influencing parasite persistence and different outcomes observed in Chagas disease. Understanding how T. cruzi evade host's innate and adaptive immune response will provide important clues to better dissect mechanisms underlying the pathophysiology of Chagas disease.
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Affiliation(s)
- Alexandre Morrot
- Institute of Microbiology, Federal University of Rio de Janeiro Rio de Janeiro, Brazil
| | - Silvina R Villar
- Institute of Clinical and Experimental Immunology of Rosario, CONICET, National University of RosarioRosario, Argentina; Faculty of Medical Sciences, National University of RosarioRosario, Argentina
| | - Florencia B González
- Institute of Clinical and Experimental Immunology of Rosario, CONICET, National University of RosarioRosario, Argentina; Faculty of Medical Sciences, National University of RosarioRosario, Argentina
| | - Ana R Pérez
- Institute of Clinical and Experimental Immunology of Rosario, CONICET, National University of RosarioRosario, Argentina; Faculty of Medical Sciences, National University of RosarioRosario, Argentina
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Inhibition of autoimmune Chagas-like heart disease by bone marrow transplantation. PLoS Negl Trop Dis 2014; 8:e3384. [PMID: 25521296 PMCID: PMC4270743 DOI: 10.1371/journal.pntd.0003384] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2014] [Accepted: 10/30/2014] [Indexed: 01/05/2023] Open
Abstract
BACKGROUND Infection with the protozoan Trypanosoma cruzi manifests in mammals as Chagas heart disease. The treatment available for chagasic cardiomyopathy is unsatisfactory. METHODS/PRINCIPAL FINDINGS To study the disease pathology and its inhibition, we employed a syngeneic chicken model refractory to T. cruzi in which chickens hatched from T. cruzi inoculated eggs retained parasite kDNA (1.4 kb) minicircles. Southern blotting with EcoRI genomic DNA digests revealed main 18 and 20 kb bands by hybridization with a radiolabeled minicircle sequence. Breeding these chickens generated kDNA-mutated F1, F2, and F3 progeny. A targeted-primer TAIL-PCR (tpTAIL-PCR) technique was employed to detect the kDNA integrations. Histocompatible reporter heart grafts were used to detect ongoing inflammatory cardiomyopathy in kDNA-mutated chickens. Fluorochromes were used to label bone marrow CD3+, CD28+, and CD45+ precursors of the thymus-dependent CD8α+ and CD8β+ effector cells that expressed TCRγδ, vβ1 and vβ2 receptors, which infiltrated the adult hearts and the reporter heart grafts. CONCLUSIONS/SIGNIFICANCE Genome modifications in kDNA-mutated chickens can be associated with disruption of immune tolerance to compatible heart grafts and with rejection of the adult host's heart and reporter graft, as well as tissue destruction by effector lymphocytes. Autoimmune heart rejection was largely observed in chickens with kDNA mutations in retrotransposons and in coding genes with roles in cell structure, metabolism, growth, and differentiation. Moreover, killing the sick kDNA-mutated bone marrow cells with cytostatic and anti-folate drugs and transplanting healthy marrow cells inhibited heart rejection. We report here for the first time that healthy bone marrow cells inhibited heart pathology in kDNA+ chickens and thus prevented the genetically driven clinical manifestations of the disease.
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Abstract
American trypanosomiasis, known as Chagas disease is a major cause of cardiomyopathy in South America. Irreversible damage to the heart can appear 10-20 years after chagasic infection. The relationship between Chagas cardiomyopathy and ischemic stroke has been reviewed. Significant variables that predict ischemic stroke in chagasic patients have been identified: apical aneurysm, cardiac insufficiency, electrocardiogram arrhythmia and female gender. Chagasic cardiomyopathy should be included in the differential diagnosis of the etiology of stroke, being a potential source of cardioembolic stroke.
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Neves BCD, Bacilio ML, Berrueta L, Salmen S, Peterson DL, Donis JH, Nuñez TJ, Davila DF. Muscarinic antibodies and heart rate responses to dynamic exercise and to the Valsalva maneuver in chronic chagasic patients. Rev Inst Med Trop Sao Paulo 2013; 55:31-7. [PMID: 23328723 DOI: 10.1590/s0036-46652013000100006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2012] [Accepted: 08/14/2012] [Indexed: 11/22/2022] Open
Abstract
We have studied the cardiac chronotropic responses to the Valsalva maneuver and to dynamic exercise of twenty chronic chagasic patients with normal left ventricular function and no segmental wall abnormalities by two-dimensional echocardiogram. The absolute increase in heart rate of the patients (Δ = 21.5 ± 10 bpm, M±SD) during the maneuver was significantly diminished when compared to controls (Δ = 31.30 ± 70, M±SD, p = 0.03). The minimum heart rate (58.24 ± 8.90 vs. 62.80 ± 10, p = 0.68) and the absolute decrease in heart rate at the end of the maneuver (Δ = 38.30 ± 13 vs. Δ = 31.47 ± 17, p = 0.10) were not different from controls. The initial heart rate acceleration during dynamic exercise (Δ = 12 ± 7.55 vs. Δ = 19 ± 7.27, M±SD, p = 0.01) was also diminished, but the heart rate recovery during the first ten seconds was more prominent in the sero-positive patients (Median: 14, Interquartile range: (9.75-17.50 vs. 5(0-8.75, p = 0.001). The serum levels of muscarinic cardiac auto-antibodies were significantly higher in the chagasic patients (Median: 34.58, Interquartile Range: 17-46.5, Optical Density) than in controls (Median: 0, Interquartile Range: 0-22.25, p = 0.001) and correlated significantly and directly (r = 0.68, p = 0.002) with early heart rate recovery during dynamic exercise. The results of this investigation indirectly suggest that, the cardiac muscarinic auto-antibodies may have positive agonist effects on parasympathetic heart rate control of chagasic patients.
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Affiliation(s)
- Barbara C das Neves
- Instituto de Investigaciones Cardiovasculares, Universidad de Los Andes, Mérida, Venezuela
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Hidalgo R, Martí-Carvajal AJ, Kwong JSW, Simancas-Racines D, Nicola S. Pharmacological interventions for treating heart failure in patients with chagas cardiomyopathy. Cochrane Database Syst Rev 2012; 11:CD009077. [PMID: 23152267 DOI: 10.1002/14651858.cd009077.pub2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
BACKGROUND Chagas disease-related cardiomyopathy is a major cause of morbidity and mortality in Latin America. Despite the substantial burden to the healthcare system, there is uncertainty regarding the efficacy and safety of pharmacological interventions for treating heart failure in patients with Chagas disease. OBJECTIVES To assess the benefits and harms of current pharmacological interventions for treating heart failure in patients with Chagas cardiomyopathy. SEARCH METHODS We searched the Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library) Issue 1, 2011, MEDLINE (Ovid), EMBASE (Ovid), LILACS and ISI Web of Science to April 2011. We checked the reference lists of included papers. No language restrictions were applied. SELECTION CRITERIA We included randomized clinical trials assessing the effects of pharmacological interventions for treating heart failure in adult patients (≥18 years) with symptomatic heart failure (New York Heart Association class II to IV), irrespective of the left ventricular ejection fraction stage, reduced or preserved, with Chagas cardiomyopathy. No limits were applied with respect to the follow-up duration. Primary outcomes were all-cause mortality, cardiovascular mortality at 30 days, time to heart decompensation and disease-free period (at 30, 60 and 90 days), and adverse events. DATA COLLECTION AND ANALYSIS Two authors independently performed study selection, risk of bias assessment and data extraction. We estimated relative risks (RR) and the respective 95% confidence intervals (CIs) for dichotomous outcomes. We measured statistical heterogeneity using the I(2) statistic. We used a fixed-effect model to synthesize the findings. We contacted authors for additional data. MAIN RESULTS We included two randomized clinical trials involving 69 participants. Both trials compared carvedilol against placebo, and had a high risk of bias. Carvedilol compared with placebo did not significantly affect all-cause mortality (2/34 (5.88%) versus 3/35 (5.87%); pooled RR 0.69, 95% CI 0.12 to 3.88, I(2) = 0%). None of the trials reported on cardiovascular mortality, time to heart decompensation or disease-free period. Evidence on the adverse effects of carvedilol is inconclusive. AUTHORS' CONCLUSIONS This Cochrane review has found a lack of evidence on the effects of carvedilol for treating heart failure in patients with Chagas disease. The two included trials were underpowered and had a high risk of bias. There are no conclusive data to support the use of carvedilol for treating Chagas cardiomyopathy. Unless randomized clinical trials provide evidence of a treatment effect, and the trade off between potential benefits and harms is established, policy-makers, clinicians, and academics should be cautious when recommending and administering carvedilol for treating heart failure in patients with Chagas disease. The efficacy and safety of other pharmacological interventions for treating heart failure in patients with Chagas disease is unknown.
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Affiliation(s)
- Ricardo Hidalgo
- Facultad de Ciencias de la Salud Eugenio Espejo, Universidad Tecnológica Equinoccial, Quito, Ecuador
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Dávila DF, Donis JH, Arata de Bellabarba G, Villarroel V, Sanchez F, Berrueta L, Salmen S, Das Neves B. Cardiac autonomic control mechanisms in the pathogenesis of chagas' heart disease. Interdiscip Perspect Infect Dis 2012; 2012:980739. [PMID: 23091486 PMCID: PMC3467757 DOI: 10.1155/2012/980739] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2012] [Accepted: 08/27/2012] [Indexed: 11/17/2022] Open
Abstract
Primary abnormalities of the autonomic nervous system had been postulated as the pathogenic mechanisms of myocardial damage, in patients with Chagas disease. However, recent investigations indicate that these abnormalities are secondary and amenable to treatment with beta-adrenergic blockers. Moreover, muscarinic cardiac autoantibodies appear to enhance parasympathetic activity on the sinus node. Therefore, the purpose of this paper is to analyze how knowledge on Chagas' disease evolved from being initially considered as a primary cardioneuromyopathy to the current status of a congestive cardiomyopathy of parasitic origin.
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Affiliation(s)
- Diego F. Dávila
- Instituto de Investigaciones Cardiovasculares, Departamento de Fisiopatología, Instituto de Inmunologìa Clinica, Facultad de Medicina, Hospital Universitario de Los Andes, Universidad de Los Andes, Mérida 5101, Venezuela
| | - Jose H. Donis
- Instituto de Investigaciones Cardiovasculares, Departamento de Fisiopatología, Instituto de Inmunologìa Clinica, Facultad de Medicina, Hospital Universitario de Los Andes, Universidad de Los Andes, Mérida 5101, Venezuela
| | - Gabriela Arata de Bellabarba
- Instituto de Investigaciones Cardiovasculares, Departamento de Fisiopatología, Instituto de Inmunologìa Clinica, Facultad de Medicina, Hospital Universitario de Los Andes, Universidad de Los Andes, Mérida 5101, Venezuela
| | - Vanesa Villarroel
- Instituto de Investigaciones Cardiovasculares, Departamento de Fisiopatología, Instituto de Inmunologìa Clinica, Facultad de Medicina, Hospital Universitario de Los Andes, Universidad de Los Andes, Mérida 5101, Venezuela
| | - Francisco Sanchez
- Instituto de Investigaciones Cardiovasculares, Departamento de Fisiopatología, Instituto de Inmunologìa Clinica, Facultad de Medicina, Hospital Universitario de Los Andes, Universidad de Los Andes, Mérida 5101, Venezuela
| | - Lisbeth Berrueta
- Instituto de Investigaciones Cardiovasculares, Departamento de Fisiopatología, Instituto de Inmunologìa Clinica, Facultad de Medicina, Hospital Universitario de Los Andes, Universidad de Los Andes, Mérida 5101, Venezuela
| | - Siham Salmen
- Instituto de Investigaciones Cardiovasculares, Departamento de Fisiopatología, Instituto de Inmunologìa Clinica, Facultad de Medicina, Hospital Universitario de Los Andes, Universidad de Los Andes, Mérida 5101, Venezuela
| | - Barbara Das Neves
- Instituto de Investigaciones Cardiovasculares, Departamento de Fisiopatología, Instituto de Inmunologìa Clinica, Facultad de Medicina, Hospital Universitario de Los Andes, Universidad de Los Andes, Mérida 5101, Venezuela
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Junqueira LF. Insights into the clinical and functional significance of cardiac autonomic dysfunction in Chagas disease. Rev Soc Bras Med Trop 2012; 45:243-52. [PMID: 22535000 DOI: 10.1590/s0037-86822012000200020] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2011] [Accepted: 01/10/2012] [Indexed: 11/21/2022] Open
Abstract
INTRODUCTION Exclusive or associated lesions in various structures of the autonomic nervous system occur in the chronic forms of Chagas disease. In the indeterminate form, the lesions are absent or mild, whereas in the exclusive or combined heart and digestive disease forms, they are often more pronounced. Depending on their severity these lesions can result mainly in cardiac parasympathetic dysfunction but also in sympathetic dysfunction of variable degrees. Despite the key autonomic effect on cardiovascular functioning, the pathophysiological and clinical significance of the cardiac autonomic dysfunction in Chagas disease remains unknown. METHODS Review of data on the cardiac autonomic dysfunction in Chagas disease and their potential consequences, and considerations supporting the possible relationship between this disturbance and general or cardiovascular clinical and functional adverse outcomes. RESULTS We hypothesise that possible consequences that cardiac dysautonomia might variably occasion or predispose in Chagas disease include: transient or sustained arrhythmias, sudden cardiac death, adverse overall and cardiovascular prognosis with enhanced morbidity and mortality, an inability of the cardiovascular system to adjust to functional demands and/or respond to internal or external stimuli by adjusting heart rate and other hemodynamic variables, and immunomodulatory and cognitive disturbances. CONCLUSIONS Impaired cardiac autonomic modulation in Chagas disease might not be a mere epiphenomenon without significance. Indirect evidences point for a likely important role of this alteration as a primary predisposing or triggering cause or mediator favouring the development of subtle or evident secondary cardiovascular functional disturbances and clinical consequences, and influencing adverse outcomes.
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Affiliation(s)
- Luiz Fernando Junqueira
- Laboratório Cardiovascular, Área de Clínica Médica (Cardiologia), Universidade de Brasilia, Brasilia, DF.
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Chuenkova MV, Pereiraperrin M. Neurodegeneration and neuroregeneration in Chagas disease. ADVANCES IN PARASITOLOGY 2011; 76:195-233. [PMID: 21884893 DOI: 10.1016/b978-0-12-385895-5.00009-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Autonomic dysfunction plays a significant role in the development of chronic Chagas disease (CD). Destruction of cardiac parasympathetic ganglia can underlie arrhythmia and heart failure, while lesions of enteric neurons in the intestinal plexuses are a direct cause of aperistalsis and megasyndromes. Neuropathology is generated by acute infection when the parasite, though not directly damaging to neuronal cells, elicits immune reactions that can become cytotoxic, inducing oxidative stress and neurodegeneration. Anti-neuronal autoimmunity may further contribute to neuropathology. Much less clear is the mechanism of subsequent neuronal regeneration in patients that survive acute infection. Morphological and functional recovery of the peripheral neurons in these patients correlates with the absence of CD clinical symptoms, while persistent neuronal deficiency is observed for the symptomatic group. The discovery that Trypanosoma cruzi trans-sialidase can moonlight as a parasite-derived neurotrophic factor (PDNF) suggests that the parasite might influence the balance between neuronal degeneration and regeneration. PDNF functionally mimics mammalian neurotrophic factors in that it binds and activates neurotrophin Trk tyrosine kinase receptors, a mechanism which prevents neurodegeneration. PDNF binding to Trk receptors triggers PI3K/Akt/GSK-3β and MAPK/Erk/CREB signalling cascades which in neurons translates into resistance to oxidative and nutritional stress, and inhibition of apoptosis, whereas in the cytoplasm of infected cells, PDNF represents a substrate-activator of the host Akt kinase, enhancing host-cell survival until completion of the intracellular cycle of the parasite. Such dual activity of PDNF provides sustained activation of survival mechanisms which, while prolonging parasite persistence in host tissues, can underlie distinct outcomes of CD.
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Affiliation(s)
- Marina V Chuenkova
- Department of Pathology and Sackler School of Graduate Students, Tufts University School of Medicine, Boston, Massachusetts, USA
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Teixeira ARL, Hecht MM, Guimaro MC, Sousa AO, Nitz N. Pathogenesis of chagas' disease: parasite persistence and autoimmunity. Clin Microbiol Rev 2011; 24:592-630. [PMID: 21734249 PMCID: PMC3131057 DOI: 10.1128/cmr.00063-10] [Citation(s) in RCA: 147] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Acute Trypanosoma cruzi infections can be asymptomatic, but chronically infected individuals can die of Chagas' disease. The transfer of the parasite mitochondrial kinetoplast DNA (kDNA) minicircle to the genome of chagasic patients can explain the pathogenesis of the disease; in cases of Chagas' disease with evident cardiomyopathy, the kDNA minicircles integrate mainly into retrotransposons at several chromosomes, but the minicircles are also detected in coding regions of genes that regulate cell growth, differentiation, and immune responses. An accurate evaluation of the role played by the genotype alterations in the autoimmune rejection of self-tissues in Chagas' disease is achieved with the cross-kingdom chicken model system, which is refractory to T. cruzi infections. The inoculation of T. cruzi into embryonated eggs prior to incubation generates parasite-free chicks, which retain the kDNA minicircle sequence mainly in the macrochromosome coding genes. Crossbreeding transfers the kDNA mutations to the chicken progeny. The kDNA-mutated chickens develop severe cardiomyopathy in adult life and die of heart failure. The phenotyping of the lesions revealed that cytotoxic CD45, CD8(+) γδ, and CD8α(+) T lymphocytes carry out the rejection of the chicken heart. These results suggest that the inflammatory cardiomyopathy of Chagas' disease is a genetically driven autoimmune disease.
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Affiliation(s)
- Antonio R L Teixeira
- Chagas Disease Multidisciplinary Research Laboratory, University of Brasilia, Federal District, Brazil.
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Martí-Carvajal AJ, Hidalgo R, Kwong J. Pharmacological interventions for treating heart failure in patients with Chagas cardiomyopathy. THE COCHRANE DATABASE OF SYSTEMATIC REVIEWS 2011. [DOI: 10.1002/14651858.cd009077] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Bowman NM, Kawai V, Gilman RH, Bocangel C, Galdos-Cardenas G, Cabrera L, Levy MZ, Cornejo del Carpio JG, Delgado F, Rosenthal L, Pinedo-Cancino VV, Steurer F, Seitz AE, Maguire JH, Bern C. Autonomic dysfunction and risk factors associated with Trypanosoma cruzi infection among children in Arequipa, Peru. Am J Trop Med Hyg 2011; 84:85-90. [PMID: 21212207 PMCID: PMC3005523 DOI: 10.4269/ajtmh.2011.10-0303] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2010] [Accepted: 08/30/2010] [Indexed: 11/07/2022] Open
Abstract
Chagas disease affects an estimated 8 million people in Latin America. Infected individuals have 20-30% lifetime risk of developing cardiomyopathy, but more subtle changes in autonomic responses may be more frequent. We conducted a matched case-control study of children in Arequipa, Peru, where triatomine infestation and Trypanosoma cruzi infection are emerging problems. We collected data on home environment, history, physical examination, electrocardiogram, and autonomic testing. Signs of triatomine infestation and/or animals sleeping in the child's room and household members with Chagas disease were associated with increased infection risk. Electrocardiogram findings did not differ between cases and controls. However, compared with control children, infected children had blunted autonomic responses by three different measures, the Valsalva maneuver, the cold pressor test, and the orthostatic test. T. cruzi-infected children show autonomic dysfunction, although the prognostic value of this finding is not clear. Sustained vector control programs are essential to decreasing future T. cruzi infections.
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Affiliation(s)
- Natalie M Bowman
- Division of Infectious Diseases, University of North Carolina-Chapel Hill, Chapel Hill, North Carolina, USA.
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Chuenkova MV, Pereiraperrin M. Trypanosoma cruzi-Derived Neurotrophic Factor: Role in Neural Repair and Neuroprotection. ACTA ACUST UNITED AC 2010; 1:55-60. [PMID: 21572925 DOI: 10.4303/jnp/n100507] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Some patients infected with the parasite Try-panosoma cruzi develop chronic Chagas' disease, while others remain asymptomatic for life. Although pathological mechanisms that govern disease progression remain unclear, the balance between degeneration and regeneration in the peripheral nervous system seems to contribute to the different clinical outcomes. This review focuses on certain new aspects of host-parasite interactions related to regeneration in the host nervous system induced by the trans-sialidase of T. cruzi, also known as a parasite-derived neurotrophic factor (PDNF). PDNF plays multiple roles in T. cruzi infection, ranging from immunosuppression to functional mimicry of mammalian neurotrophic factors and inhibition of apoptosis. PDNF affinity to neurotrophin Trk receptors provide sustained activation of cellular survival mechanisms resulting in neuroprotection and neuronal repair, resistance to cytotoxic insults and enhancement of neuritogenesis. Such unique PDNF-elicited regenerative responses likely prolong parasite persistence in infected tissues while reducing neuropathology in Chagas' disease.
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Affiliation(s)
- Marina V Chuenkova
- Department of Pathology, Tufts University School of Medicine, 150 Harrison Avenue, Boston, MA 02111, USA
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Gutiérrez O, Garita E, Salazar C. Autonomic nervous system and preventive treatment of ventricular arrhythmias in chagasic disease. Int J Cardiol 2009; 137:291-2. [PMID: 18684534 DOI: 10.1016/j.ijcard.2008.05.044] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/12/2008] [Accepted: 05/10/2008] [Indexed: 10/21/2022]
Abstract
Non-pharmacological preventive treatment of sustained ventricular arrhythmias in chagasic disease is a challenge. Given that the involvement of the autonomic nervous system is one of its determinants, thoracic sympathectomy could be a valuable tool in some selected cases.
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Ribeiro ALP, Cassini P, Peixoto SV, Lima-Costa MF. Vagal impairment in elderly Chagas disease patients: a population-based study (the Bambuí study). Int J Cardiol 2009; 147:359-65. [PMID: 19875184 DOI: 10.1016/j.ijcard.2009.10.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/27/2009] [Revised: 07/11/2009] [Accepted: 10/11/2009] [Indexed: 11/30/2022]
Abstract
BACKGROUND Chagas disease (ChD) will become predominantly a disease of the elderly, as a consequence of the effectiveness of control measures in many Latin American countries. The effects of the disease in old age have received little attention. We investigated the effects of ageing in the association between cardiac vagal impairment, a typical feature of ChD, and chronic Trypanosoma cruzi infection. METHODS The study sample of this cross-sectional study consists of 1014 subjects ≥ 60 years old (mean age = 68.3; SD = 6.9) residing in Bambuí City (Southeast Brazil). ECG was recorded and one-breath sinus arrhythmia test was performed. Maximal expiratory over the minimal inspiratory (E:I) ratio and heart rate variability (HRV) measurements were calculated. Ordinal logistic regression was used to assess the relation between vagal indexes and chronic T. cruzi infection. RESULTS The prevalence of T. cruzi infection was 32.0% and of major ECG abnormalities, 43.4%. Among individuals aged 60-69 years, T. cruzi infection was significantly and independently associated with reduced SDNN (OR 0.38; 95% CI 0.27-0.53), RMSSD (OR 0.48; 0.34-0.67) and EI: ratio (OR 0.45; 95% CI 0.33-0.63). Among individuals aged >70 years, no significant odds ratios were found in either the unadjusted or the adjusted analysis. The presence of major ECG abnormalities did not affect the association between vagal indexes and T. cruzi infection. CONCLUSIONS Disease-specific vagal cardiac dysfunction was observed in ChD individuals below 70. However, further ageing interferes significantly with vagal heart modulation, attenuating the difference of HRV indexes between ChD and non-ChD subjects.
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Affiliation(s)
- Antonio Luiz P Ribeiro
- Faculdade de Medicina, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil.
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Beta-adrenergic blockers in chronic systolic heart failure secondary to Chagas' disease. Int J Cardiol 2008; 128:1-4. [PMID: 18378338 DOI: 10.1016/j.ijcard.2008.01.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/26/2007] [Accepted: 01/20/2008] [Indexed: 11/22/2022]
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Gutiérrez O, Garita E, Salazar C. Thoracoscopic sympathectomy for incessant polymorphic ventricular tachycardia in chronic chagasic myocarditis A case report. Int J Cardiol 2007; 119:255-7. [PMID: 17079033 DOI: 10.1016/j.ijcard.2006.07.138] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/02/2006] [Revised: 07/27/2006] [Accepted: 07/29/2006] [Indexed: 10/24/2022]
Abstract
Management of complex ventricular arrhythmias due to chagasic myocarditis is challenging. We herein present the case of a young male who was presented with incessant well tolerated polymorphic ventricular tachycardia of unknown cause, who was unresponsive to conventional medical management and as a last resort was submitted to a thoracoscopic bilateral sympathectomy, and showed remarkable improvement in his arrhythmia control. Later on his tests returned positive for Chagas' disease and shortly thereafter he suddenly died.
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Teixeira ARL, Nascimento RJ, Sturm NR. Evolution and pathology in chagas disease--a review. Mem Inst Oswaldo Cruz 2007; 101:463-91. [PMID: 17072450 DOI: 10.1590/s0074-02762006000500001] [Citation(s) in RCA: 154] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2006] [Accepted: 06/07/2006] [Indexed: 02/04/2023] Open
Abstract
Trypanosoma cruzi acute infections often go unperceived, but one third of chronically infected individuals die of Chagas disease, showing diverse manifestations affecting the heart, intestines, and nervous systems. A common denominator of pathology in Chagas disease is the minimal rejection unit, whereby parasite-free target host cells are destroyed by immune system mononuclear effectors cells infiltrates. Another key feature stemming from T. cruzi infection is the integration of kDNA minicircles into the vertebrate host genome; horizontal transfer of the parasite DNA can undergo vertical transmission to the progeny of mammals and birds. kDNA integration-induced mutations can enter multiple loci in diverse chromosomes, generating new genes, pseudo genes and knock-outs, and resulting in genomic shuffling and remodeling over time. As a result of the juxtaposition of kDNA insertions with host open reading frames, novel chimeric products may be generated. Germ line transmission of kDNA-mutations determined the appearance of lesions in birds that are indistinguishable from those seen in Chagas disease patients. The production of tissue lesions showing typical minimal rejection units in birds' refractory to T. cruzi infection is consistent with the hypothesis that autoimmunity, likely triggered by integration-induced phenotypic alterations, plays a major role in the pathogenesis of Chagas disease.
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Affiliation(s)
- Antonio R L Teixeira
- Laboratório de Pesquisa Multidisciplinar em Doença de Chagas, Faculdade de Medicina, Universidade de Brasilia, Caixa Postal 04536, 70919-970 Brasilia,-DF, Brasil.
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Dávila DF, Donis JH, Dávila LA, Odreman WA, de Bellabarba GA, Villarroel V. Anti-muscarinic autoantibodies and vagal modulation in Chagas disease: positive allosteric modulators vs desensitization and downregulation of M2 cardiac acetylcholine receptors. Int J Cardiol 2007; 123:328-9; author reply 330-2. [PMID: 17336411 DOI: 10.1016/j.ijcard.2006.11.176] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/10/2006] [Accepted: 11/18/2006] [Indexed: 11/20/2022]
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Punukollu G, Gowda RM, Khan IA, Navarro VS, Vasavada BC. Clinical aspects of the Chagas' heart disease. Int J Cardiol 2007; 115:279-83. [PMID: 16769134 DOI: 10.1016/j.ijcard.2006.03.004] [Citation(s) in RCA: 91] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/22/2005] [Revised: 11/29/2005] [Accepted: 03/11/2006] [Indexed: 11/30/2022]
Abstract
Chagas' heart disease, caused by protozoan Trypanosoma cruzi, is a common cause of cardiomyopathy in the Americas. Transmission of T. cruzi occurs through Reduviids, the kissing bugs. Less common ways of transmission are blood transfusion, congenital transmission, organ transplantation, laboratory accident, breastfeeding, and oral contamination. Infestation results in cardiac dysautonomia, myocardial apoptosis, and myocardial fibrosis. In acute phase, death is mostly caused by myocarditis and in chronic phase, it is mostly by irreversible cardiomyopathy. A majority of the patients with Chagas' disease remain in the latent phase of disease for 10 to 30 years or even for life. Specific anti-Chagas' therapy with trypanocide drugs is useful in acute phase but the management of chronic Chagas' heart disease is mostly empirical. The mortality during the acute phase of cardiac Chagas is around 5%. Five-year mortality of chronic Chagas' disease with cardiac dysfunction is above 50%. The clinical aspects of the Chagas' heart disease are concisely reviewed.
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Abstract
AbstractChagas disease, caused by the obligate unicellular parasite Trypanosoma cruzi, presents itself in a diverse collection of clinical manifestations, ranging from severe, fatal heart and digestive tract pathologies to unapparent or minor alterations that do not compromise survival. Over the years, a number of mechanisms have been proposed to explain the pathogenesis of chagasic tissue lesions, all of which have faced some criticism or been received with skepticism. This article excludes the autoimmunity hypothesis for Chagas disease because it has been extensively reviewed elsewhere, and summarizes the various alternative hypotheses that have been advanced over the years. For each of these hypotheses, an outline of its main tenets and key findings that support them is presented. This is followed by the results and comments that have challenged them and the caveats that stand on their way to wider acceptance. It is hoped that this writing will draw attention to our shortcomings in understanding the pathogenesis of Chagas disease, which, unfortunately, continues to figure among the most serious health problems of the American continent.
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Chuenkova MV, Pereiraperrin M. Enhancement of tyrosine hydroxylase expression and activity by Trypanosoma cruzi parasite-derived neurotrophic factor. Brain Res 2006; 1099:167-75. [PMID: 16806115 DOI: 10.1016/j.brainres.2006.04.128] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2006] [Revised: 04/21/2006] [Accepted: 04/27/2006] [Indexed: 11/20/2022]
Abstract
A parasite-derived protein, PDNF, produced by the Chagas' disease agent Trypanosoma cruzi, functionally mimics mammalian neurotrophic factors by delaying apoptotic death and promoting survival and differentiation of neurons, including dopaminergic cells, through the activation of nerve growth factor receptor TrkA. Because it is well established that neurotrophic factors regulate enzymes involved in the biosynthesis of neurotransmitters, we examined whether PDNF could also directly activate tyrosine hydroxylase (TH), a rate-limiting enzyme in the synthesis of dopamine and other catecholamine neurotransmitters. We found that primary cultures of rat ventral mesencephalon responded to PDNF by increasing the number of TH-positive neurons and, most importantly, preserved expression of TH in neurons treated with Parkinson disease-inducing neurotoxin 1-methyl-4-phenyl pyridinium (MPP(+)). In dopaminergic PC12 cells, PDNF induced TH transcription via CRE element in TH promoter followed by significant increase in TH protein and expansion of TH-positive cell population. Furthermore, PDNF stimulated TH enzymatic activity by enhancing phosphorylation of seryl residues 31 and 40 through the activation of MAPK/Erk1/2 and cAMP-dependent protein kinase A signaling, respectively. Therefore, our results indicate that PDNF, in addition to its functioning as survival and differentiation-promoting factor for dopaminergic neuronal cells, can directly influence activity of the rate-limiting enzyme that underlies catecholamine biosynthetic cascade. This novel feature of PDNF should help understand the mechanism of neuronal function altered by T. cruzi infection, specifically neurotransmitter secretion. In addition, the findings have potential implications in the therapy of Chagas' and other neurodegenerative disorders.
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Affiliation(s)
- Marina V Chuenkova
- Parasitology Research Center, Department of Pathology, Tufts University School of Medicine, Boston, MA 02111, USA
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Molina RBG, Matsubara BB, Hueb JC, Zanati SG, Meira DA, Cassolato JL, Paiva SAR, Zornoff LAM. Dysautonomia and ventricular dysfunction in the indeterminate form of Chagas disease. Int J Cardiol 2006; 113:188-93. [PMID: 16376440 DOI: 10.1016/j.ijcard.2005.11.010] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/28/2005] [Revised: 09/28/2005] [Accepted: 11/05/2005] [Indexed: 11/19/2022]
Abstract
BACKGROUND The associations between autonomic function and biventricular function in patients with the indeterminate form of Chagas disease remains to be elucidated. METHODS In 42 asymptomatic patients and 19 healthy volunteers, the autonomic function was assessed by time domain indices of heart rate variability (HRV), analyzed for 24 h; the right ventricular function was assessed by fraction area change, right ventricle shortening, and systolic excursion of the tricuspid valve; and the left ventricular function was assessed by ejection fraction and transmitral flow velocities. Data were expressed as mean+/-SD or medians (including the lower quartile and upper quartile). Groups were compared by Student's t or Mann-Whitney U test. Autonomic and ventricular function were correlated by Pearson's or Spearman's correlation coefficient. The level of significance was 5%. RESULTS Right and left ventricular systolic function indexes were comparable between groups. Transmitral flow velocities were decreased in the Chagas disease group (p<0.05). The patients presented impaired HRV as indicated by the values of SDNN-day (80 (64-99) ms vs. 98 (78-127) ms; p=0.045), SDNNI-24 h (54 (43-71) vs. 65 (54-105) ms; p=0.027), SDNNI-day (49 (42-64) vs. 67 (48-76) ms; p=0.045), pNN50-day (2.2 (0.7-5)% vs. 10 (3-11)%; p=0.033); and pNN50-24 h (3 (1-7)% vs. 12 (8-19)%; p=0.013). There were no correlations between the left ventricular diastolic indices and autonomic dysfunctional indices (p>0.05). CONCLUSION Patients with the indeterminate form of Chagas disease have both dysautonomia and left ventricular diastolic dysfunction. However, the right ventricular function is preserved. Importantly, ventricular diastolic dysfunction and dysautonomia are independent phenomena.
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Affiliation(s)
- Roberta B G Molina
- Departamento de Clínica Médica, Faculdade de Medicina de Botucatu-Universidade Estadual Paulista, UNESP, Brazil
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Dávila-Spinetti DF, Colmenarez-Mendoza HJ, Lobo-Vielma L. Mecanismos causantes de la progresión del daño miocárdico en la enfermedad de Chagas crónica. Rev Esp Cardiol 2005. [DOI: 10.1157/13078546] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Ribeiro ALP, Lombardi F, Sousa MR, Rocha MOC. Vagal dysfunction in Chagas disease. Int J Cardiol 2005; 103:225-6; author reply 227-9. [PMID: 16080990 DOI: 10.1016/j.ijcard.2004.11.007] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/14/2004] [Accepted: 11/13/2004] [Indexed: 10/25/2022]
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Dávila DF, Santiago JJ, Odreman WA. Vagal dysfunction and the pathogenesis of chronic Chagas disease. Int J Cardiol 2005; 100:337-9. [PMID: 15823646 DOI: 10.1016/j.ijcard.2004.11.006] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/01/2004] [Accepted: 11/13/2004] [Indexed: 11/22/2022]
Abstract
Vagal dysfunction is thought to be an early, primary and specific abnormality of chronic Chagas disease. However, chagasic patients with unequivocal evidence of heart disease, can have normal or abnormal vagal control of heart rate. A common explanation for these apparently discordant and contradictory results is proposed.
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