GUILHERME VEIGA GUIMARAES
Projetos de Pesquisa
Unidades Organizacionais
Departamento de Cardio-Pneumologia, Faculdade de Medicina
Instituto do Coração, Hospital das Clínicas, Faculdade de Medicina
LIM/11 - Laboratório de Cirurgia Cardiovascular e Fisiopatologia da Circulação, Hospital das Clínicas, Faculdade de Medicina
Instituto do Coração, Hospital das Clínicas, Faculdade de Medicina
LIM/11 - Laboratório de Cirurgia Cardiovascular e Fisiopatologia da Circulação, Hospital das Clínicas, Faculdade de Medicina
7 resultados
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- Physical Exercise and MicroRNAs: New Frontiers in Heart Failure(2012) FERNANDES-SILVA, Miguel Morita; CARVALHO, Vagner Oliveira; GUIMARAES, Guilherme Veiga; BACAL, Fernando; BOCCHI, Edimar AlcidesAlthough the impact of exercise on survival of patients with heart failure has been recently questioned, exercise training improves quality of life, functional capacity, inflammation, endothelial and autonomic function. In recent years, interest has increased regarding a group of small non-protein coding RNAs called microRNAs. Studies have shown that the expression of these molecules changes in several pathological conditions, such as myocardial infarction, myocardial ischemia and heart failure, and when clinical improvement occurs, they seem to normalize. With the potential for practical applicability, markers that may be useful in diagnostic and prognostic assessment of heart failure have been identified, such as miR-423-5p. In addition, results of experimental studies have indicated that there are potential therapeutic effects of microRNAs. MicroRNAs are involved in the regulation of gene expression during fetal development and in adult individuals, increasing or decreasing in the heart in response to physiological stress, injury or hemodynamic overload. Thus, the study of the behavior of these molecules in physical exercise has brought important information about the effects of this therapeutic modality and represents a new era in the understanding of heart failure. This review aims to integrate the evidence on microRNAs in heart failure with greater relevance in the study of physical exercise.
- MicroRNAs: A New Paradigm in the Treatment and Diagnosis of Heart Failure?(2012) OLIVEIRA-CARVALHO, Vagner; CARVALHO, Vitor Oliveira; SILVA, Miguel Morita; GUIMARAES, Guilherme Veiga; BOCCHI, Edimar AlcidesMicroRNAs (miRNAs) are a group of newly discovered small RNAs, non-coding, which represent one of the most exciting areas of modern medical science as they modulate a huge and complex regulatory network of gene expression. Lines of evidence have recently suggested that miRNAs play a key role in the pathogenesis of heart failure. Some miRNAs highly expressed in the heart, such as miR-1, miR-133 and miR-208, are strongly associated with the development of cardiac hypertrophy, while the exact role of miR-21 in the cardiovascular system remains controversial. Serum levels of circulating miRNAs such as miR-423-5p are being evaluated as potential biomarkers in the diagnosis and prognosis of heart failure. On the other hand, the manipulation of levels of miRNAs using techniques such as mimicking the miRNAs (miRmimics) and antagonistic miRNAs (antagomiRs) is making increasingly evident the enormous potential of miRNAs as promising therapeutic strategies in heart failure.
article 19 Citação(ões) na Scopus Comportamento do ergorreflexo na insuficiência cardíaca(2011) BELLI, Juliana Fernanda Canhadas; BACAL, Fernando; BOCCHI, Edimar Alcides; GUIMARAES, Guilherme VeigaA large body of evidence has suggested the existence of a reflex network that becomes hyperactive secondary to musculoskeletal alterations that occur in heart failure (HF) syndrome. Together with sympathoinhibitory cardiovascular reflexes, suppressed in the presence of the syndrome, heart failure can contribute to physical exercise intolerance. The hyperactivation of signals originated from receptors located in skeletal muscles (mechanoreceptors - metaboreceptors) is a recently proposed hypothesis to explain the origin of fatigue and dyspnea symptoms in HF. In HF, other alterations in the reflex control system, which are not mutually exclusive, contribute to dyspnea. The inappropriate stimulation of the arterial baroreceptors, with the consequent lack of inhibition of the muscle metaboreflex and carotid chemoreflex unloading and the increase in the renal vasoconstriction with angiotensin II release can also be considered. Although the functional alterations of the reflexes were used independently to illustrate the sympathetic excitation observed in HF, the interaction between these reflexes under normal and pathological conditions, especially its contribution to the sympathoexcitatory state found in HF, has not been broadly investigated. Therefore, questions about a possible association between the muscle receptors (mechano and metaboreceptors) in the genesis of the ergoreflex exacerbation, observed in HF, remain. Thus, the objective of this review was to integrate the knowledge on the mechano and metaboreflex (ergoreflex) in HF syndrome, as well as to clarify the influence of HF drug therapy on the ergoreflex.- Endothelial function in pre-pubertal children at risk of developing cardiomyopathy: a new frontier(2012) TAVARES, Aline Cristina; BOCCHI, Edimar Alcides; GUIMARAES, Guilherme VeigaAlthough it is known that obesity, diabetes, and Kawasaki's disease play important roles in systemic inflammation and in the development of both endothelial dysfunction and cardiomyopathy, there is a lack of data regarding the endothelial function of pre-pubertal children suffering from cardiomyopathy. In this study, we performed a systematic review of the literature on pre-pubertal children at risk of developing cardiomyopathy to assess the endothelial function of pre-pubertal children at risk of developing cardiomyopathy. We searched the published literature indexed in PubMed, Bireme and SciELO using the keywords 'endothelial', 'children', 'pediatric' and 'infant' and then compiled a systematic review. The end points were age, the pubertal stage, sex differences, the method used for the endothelial evaluation and the endothelial values themselves. No studies on children with cardiomyopathy were found. Only 11 papers were selected for our complete analysis, where these included reports on the flow-mediated percentage dilatation, the values of which were 9.80 +/- 1.80, 5.90 +/- 1.29, 4.50 +/- 0.70, and 7.10 +/- 1.27 for healthy, obese, diabetic and pre-pubertal children with Kawasaki's disease, respectively. There was no significant difference in the dilatation, independent of the endothelium, either among the groups or between the genders for both of the measurements in children; similar results have been found in adolescents and adults. The endothelial function in cardiomyopathic children remains unclear because of the lack of data; nevertheless, the known dysfunctions in children with obesity, type 1 diabetes and Kawasaki's disease may influence the severity of the cardiovascular symptoms, the prognosis, and the mortality rate. The results of this study encourage future research into the consequences of endothelial dysfunction in pre-pubertal children.
- Aerobic Exercise Prescription in Adult Heart Transplant Recipients: A Review(2011) CARVALHO, Vitor Oliveira; BOCCHI, Edimar Alcides; GUIMARAES, Guilherme VeigaBackground: Heart transplantation is a gold-standard treatment for selected patients in the terminal stages of heart failure and it can improve patients' quality of life, exercise capacity, and survival. Despite of the exercise performance in heart transplant recipients increases with respect to pre-transplantation, it still remains subnormal when compared with healthy subjects. Exercise training is an important nonpharmacological tool in heart transplant recipients to improve the exercise capacity, muscle strength, quality of life, and the chronotropic response. Despite this there is no consensus about what methods of aerobic exercise prescription are more adequate. Aim: The purpose of this review is to provide an up-to-date summary of the direct and indirect methods of prescription of aerobic exercise training in heart transplant recipients. Conclusion: The indirect methods of aerobic exercise prescription seem to be very frail and they do not seem to be reliable in heart transplant recipients.
- A meta-analysis of cardiopulmonary exercise testing in pre-pubertal healthy children produces new information(2016) TAVARES, Aline Cristina; BOCCHI, Edimar Alcides; TEIXEIRA NETO, Iram Soares; GUIMARÃES, Guilherme VeigaThe objective of the paper was to analyze cardiopulmonary data and functional capacity in healthy children who have undergone ergospirometry. A systematic meta-analysis review of ergospirometry in children was performed based on reports indexed in PubMed, Bireme, and Embase. End points were age, sex, body mass index, maturation evaluation, the type of ergometer used for ergospirometry, and cardiopulmonary related values (peak heart rate and peak oxygen consumption [VO2]). Twenty articles were selected, which included 3,808 children, averaging 9.1years of age. A treadmill was used in 55% of the trials, and a cycle ergometer in the other 45% studies included in this analysis. The following statistically significant results were found: on subgroup analysis, peak VO2 values in boys on the treadmill was 20% higher than peak VO2 values in girls on the cycle ergometer; peak VO2 values in boys on the treadmill were 18% greater than that for girls on the same ergometer. BMI was inversely correlated with peak VO2 in the total analysis, and in female subjects on cycle ergometers. Peak heart rate during the ergospirometrical test was 5.6 BPM higher than the estimated 95% maximum heart rate. Most of the ergospirometrical parameters had not been reported in the original trials analyzed here. We conclude that peak VO2 value for pre-pubertal children are circa 18% higher in boys vs. girls and overall higher in treadmill vs. cycle ergometers.
- Contemporary review of exercise in heart transplant recipients(2021) GUIMARAES, Guilherme Veiga; RIBEIRO, Fernando; ARTHUSO, Fernanda Zane; CASTRO, Rafael Ertner; CORNELISSEN, Veronique; CIOLAC, Emmanuel GomesHeart transplantation (HTx) is a therapeutic option for a selected group of patients with end-stage heart failure. Although secondary prevention including exercise therapy is recommended in the management of patients following HTx, little information is available on their metabolic and physiological consequences in HTx. Therefore, we aimed to conduct a contemporary review the effectiveness of exercise therapy on functional capacity, cardiovascular health and health-related quality of life for adult HTx patients. We searched the database MEDLINE for articles published between January 2015 and October 2020 and were able to include 6 studies involving 202 patients. Larger improvements in exercise capacity were seen after high-intensity interval training and in patients with evidence of cardiac reinnervation. Clinically relevant reductions were observed for daytime and 24 h ambulatory blood pressure after exercise training and following a single bout of aerobic exercise. Finally, limited data suggest that quality of life is higher in HTx patients following high-intensity training. In summary, the available evidence shows the potential for exercise as a vital treatment in patients following HTx. Yet, the scant data calls for more well-designed and adequately powered studies to support its effectiveness and to unravel optimal exercise characteristics, which would allow for more effective and person-tailored exercise prescription.