Papers by GUILHERME VEIGA GUIMARAES
International Journal of Sports Medicine, Feb 21, 2019
Keeping blood pressure levels within the normal range is a clinical challenge in patients with hy... more Keeping blood pressure levels within the normal range is a clinical challenge in patients with hypertension. Studies have shown favorable benefits of regular exercise in controlling blood pressure. However, the hypotensive effects of exercise return to pretraining of BP levels within 3 months after cessation of exercise. This study demonstrated that the effects of heated waterbased exercise on blood pressure persisted after 3 months of cessation of exercise in patients with resistant hypertension.
Clinical and Experimental Hypertension, Apr 19, 2022
OBJECTIVES This crossover study design aimed to assess hemodynamic, cardiac autonomic, and vascul... more OBJECTIVES This crossover study design aimed to assess hemodynamic, cardiac autonomic, and vascular responses to high-intensity interval (HIIE) vs moderate-intensity continuous exercise (MICE) in older individuals with hypertension. METHODS Twenty (67 ± 7 y) older individuals with hypertension were randomly assigned to perform HIIE, MICE, or control (CON) sessions in the heated swimming pool (30-32°C). Blood pressure (BP), arterial stiffness, endothelial reactivity, and heart rate variability (HRV) were measured pre, post, and 45 min (recovery) after each intervention followed by 24-h ambulatory BP and HRV. RESULTS One single aerobic exercise session was not effective to provoke post-exercise hypotension and vascular improvements. HIIE was superior to MICE and CON to increasing parasympathetic modulation at post and recovery. Exercise sessions showed to disturb the autonomic system at nighttime compared to CON. CONCLUSIONS These results may have important implications in water-based therapy and the elderly with hypertension.
Medicine and Science in Sports and Exercise, May 1, 2017
High-intensity interval training (HIIT) is a time-efficient intervention for preventing and treat... more High-intensity interval training (HIIT) is a time-efficient intervention for preventing and treating type 2 diabetes (T2D). Rate of perceived exertion scale (RPE) is a simple and inexpensive tool for prescribing and self-regulating exercise. Our purpose was to analyze the hemodynamic and metabolic response to a HIIT session prescribed and self-regulated by RPE (HIIT RPE) in T2D patients. METHODS: Ten (two males) T2D patients (time since diagnosis = 9.1 ± 1.7 yr) aged 50.7 ± 2.8 yr underwent a symptom-limited CPX on a treadmill to determine their heart rate (HR) response to exercise. Patients were then assigned to perform of HIIT RPE (4 min of warm-up and 21 min of jogging/running at 15-17 (1 min) alternating with walking at 9-11 (2 min) on the 6-20 RPE scale), HIIT prescribed and regulated by HR response to CPX (HIIT HR , 4 min of warm-up and 21 min of jogging/running at 85% (1 min) alternating with walking at 50% (2 min) of reserve HR), continous moderate exercise (CME) prescribed and self-regulated by RPE (30 min of walking at 11-13 on the 6-20 RPE scale), and control session (CON, sitting in a quiet environment) in a random order (3 to 7 days between intervention). Capillary glucose, endothelial function and carotidfemoral pulse wave velocity (PWV) were assessed before, immediately after and 45 min after each intervention. 24-h ambulatory blood pressure (ABP) after each intervention. RESULTS: Exercise distance was not different between all interventions. Exercise HR and speed were also not different between HIIT RPE and HIIT HR. T2D patients showed similar reductions in capillary glucose after HIIT RPE (21.9±4.0%) and HIIT HR (25.2±4.8%), wich were greater (P < 0.05) than the observed after CME (16.4±6.2%). T2D patients also showed similar nighttime ABP reductions after HIIT RPE and HIIT HR , when compared to CON; but the reduction was statistically significant (P < 0.05) only after HIIT RPE. No ABP reductions was found after CME. No significant differences on endothelial function and PWV were observed during all interventions. CONCLUSION: HIIT was superior to CME to acutely reduce capillary glucose and ABP, independently if it was prescribed and regulated by RPE or the HR response to CPX. This result suggest that the 6-20 RPE scale may be an efficient tool for prescribing and self-regulating HIIT in T2D patients.
Esc Heart Failure, Oct 9, 2018
Revista Brasileira De Medicina Do Esporte, Oct 1, 2004
After heart transplantation patients improve their quality of life. However, they frequently have... more After heart transplantation patients improve their quality of life. However, they frequently have clinical problems in the post operative period, as physical deconditioning, muscular atrophy, weakness and lower maximal aerobic capacity, in part due to the inactivity in the preoperative period and to factors as the difference in donor/receptor body surface, heart denervation, among others. Regular physical activity plays an important role in heart transplanted patients follow-up and should be recommended as soon as possible, may be in predischarge phase, going on after discharge, which could help patients to have a satisfactory lifestyle , similar to what they had before the disease, returning to active and productive life.
Esc Heart Failure, Dec 20, 2017
Aims The SHIFT trial showed that ivabradine reduced heart rate (HR) and the risk of cardiovascula... more Aims The SHIFT trial showed that ivabradine reduced heart rate (HR) and the risk of cardiovascular outcomes. Concerns remain over the efficacy and safety of ivabradine on heart failure (HF) due to Chagas disease (ChD). We therefore conducted a post hoc analysis of the SHIFT trial to investigate the effect of ivabradine in these patients. Methods and results SHIFT was a randomized, double-blind, placebo-controlled trial in symptomatic systolic stable HF, HR ≥ 70 b.p.m., and in sinus rhythm. The ChD HF subgroup included 38 patients, 20 on ivabradine, and 18 on placebo. The ChD HF subgroup showed high prevalence of bundle branch right block and, compared with the overall SHIFT population, lower systolic blood pressure; higher use of diuretics, cardiac glycosides, and antialdosterone agents; and lower use of angiotensin-converting enzyme inhibitor/angiotensin II receptor blocker or target daily dose of beta-blocker. ChD HF presented a poor prognosis (all-cause mortality at 2 years was~60%). The mean twice-daily dose of ivabradine was 6.26 ± 1.15 mg and placebo 6.43 ± 1.55 mg. Ivabradine reduced HR from 77.9 ± 3.8 to 62.3 ± 10.1 b.p.m. (P = 0.005) and improved functional class (P = 0.02). A trend towards reduction in all-cause death was observed in ivabradine arm vs. placebo (P = 0.07). Ivabradine was not associated with serious bradycardia, atrioventricular block, hypotension, or syncope. Conclusions ChD HF is an advanced form of HF with poor prognosis. Ivabradine was effective in reducing HR in these patients and improving functional class. Although our results are based on a very limited sample and should be interpreted with caution, they suggest that ivabradine may have a favourable benefit-risk profile in ChD HF patients.
International Journal of Cardiology, Nov 1, 2010
ABSTRACT In healthy subjects, the percentage of heart rate reserve (%HRR) versus the percentage o... more ABSTRACT In healthy subjects, the percentage of heart rate reserve (%HRR) versus the percentage of oxygen consumption reserve (%VO(2)R) is the closest relationship between heart rate and VO(2) and it seems also to be true to heart failure patients only if they are under optimized beta-blocker therapy. To evaluate the closest relationship between heart rate and VO(2) (%peak heart rate versus %peak VO(2); %HRR versus %VO(2)R or absolute heart rate versus absolute VO(2)) in heart transplant recipients during a treadmill cardiopulmonary exercise test. A total of 19 sedentary heart transplant recipients (5.4 ± 3.3 years after transplant) in a stable condition (for, at least, 3 months), were recruited to perform a cardiopulmonary exercise test. The relationship between %HRR-%VO(2)R, %peak heart rate versus %peak VO(2) and absolute heart rate versus absolute VO(2) were tested. The strongest relationship was found between %HRR-%VO(2)R (r = 0.95, p&lt;0.0001), followed by %peak heart rate versus %peak VO(2) (r = 0.91, p&lt;0.0001) and absolute heart rate versus absolute VO(2) (r = 0.67, p&lt;0.0001). The mean regression line did not coincide with the line of identity in any group (p&lt;0.0001 for all groups). The %HRR versus %VO(2)R showed the closest relationship followed by %peak heart rate versus %peak VO(2) and absolute heart rate versus absolute VO(2). Despite this, the perfect reliability of the heart rate versus VO(2) was not found.
Journal of Indian College of Cardiology, Jun 1, 2018
Background: Idiopathic dilated cardiomyopathy prognosis is influenced by endothelial dysfunction ... more Background: Idiopathic dilated cardiomyopathy prognosis is influenced by endothelial dysfunction in adults with heart failure but this information is lacking in children. Objective: Evaluate endothelial function in children with IDCM and HF. Method: The idiopathic dilated cardiomyopathy group (IDCM) was composed of 15 children with left ventricular ejection fraction <40%. The heart failure group (HF) was composed of 16 children with left ventricular ejection fraction (LVEF) >50% who had previously been diagnosed with idiopathic dilated cardiomyopathy. The control group (CON) was composed of 11 healthy children. The endothelial function in all children was assessed via reactive hyperemia index (RHI)peripheral artery tonometry testing and cardiopulmonary exercise test. Results: IDCM were significantly shorter than CON (1.2 Â 1.4 in m, respectively) and they received higher carvedilol, captopril, and furosemide dosage. CON presented RHI = 1.53 AE 0.26. HF presented RHI = 1.14 AE 0.31. IDCM presented RHI = 1.04 AE 0.24. CON showed a RHI 31% higher than HF and 25% higher than IDCM, significantly. LVEF was moderately correlated to the RHI (r = 0.46). For each unit of RHI, there was an addition of 10.57 in maximal oxygen consumption (VO 2 max). Lower RHI values correlated with lower VO 2 max values. Conclusion: Children with IDCM and HF had endothelial dysfunction. The endothelium remained dysfunctional even after improvement in cardiac function.
International Journal of Cardiovascular Sciences, 2017
The FASEB Journal, Apr 1, 2020
BackgroundModerate intensity continuous exercise (MICT) has been shown to reduce muscle sympathet... more BackgroundModerate intensity continuous exercise (MICT) has been shown to reduce muscle sympathetic nerve activity (MSNA) in heart failure patients with reduced ejection fraction (HFrEF). However, the effects of high‐intensity interval training (HIIT) on MSNA in HFrEF patients are unknown. We hypothesized that reductions in MSNA would be greater following HIIT than MICT and correspond with improvements in peripheral vascular function.MethodsHFrEF patients (30 ‐ 65 years), left ventricular ejection fraction ≤ 40%, Functional Classes II–III, were randomized into HIIT, MICT or no training (NT) three times/week for 12 weeks. MSNA was assessed by microneurography. Brachial artery flow‐mediated dilation (FMD), blood flow and vascular conductance were assessed by ultrasonography, blood pressure (BP) and heart rate (HR) by plethysmography and peak oxygen uptake (V̇O2peak) by a cardiopulmonary exercise test.ResultsBoth, HIIT and MICT, led to reductions in MSNA (frequency and incidence burst) relative to NT (p&lt;0.05). However, the reduction in MSNA was more pronounced following HIIT than MICT (p&lt;0.05). Increases in brachial artery FMD, resting blood flow and conductance were also greater following HIIT than MICT (p&lt;0.05), while V̇O2peak increased similarly following HIIT and MICT relative to NT. No changes in BP or HR were observed in either exercise condition. Further analysis showed a negative correlation between changes in MSNA and FMD following the interventions (r=−0.60, p=0.005).ConclusionOur findings indicate that 12 weeks of HIIT is superior to MICT in reducing sympathetic overactivity and improving vascular function in patients with HFrEF, despite similar increases in exercise capacity.Support or Funding InformationFAPESP Grants (2014/11671‐6 and 2017/25613‐6)
Chest, Sep 1, 2001
Guimarães, Guilherme Veiga; Bellotti, Giovanni; Mocelin, Amilcar Oshiro; Camargo, Paulo Roberto; ... more Guimarães, Guilherme Veiga; Bellotti, Giovanni; Mocelin, Amilcar Oshiro; Camargo, Paulo Roberto; Bocchi, Edimar Alcides.
Journal of the American College of Cardiology, 2017
Background: Ivabradine reduces heart rate (HR) and significantly reduced cardiovascular risk in t... more Background: Ivabradine reduces heart rate (HR) and significantly reduced cardiovascular risk in the SHIFT trial. There are concerns limiting the generalization of efficacy and safety for chagasic etiology (CH)-HF due to persistent myocarditis, fibrosis; sinus node dysfunction, conduction disorders, and worse prognosis in CH-HF. We investigated whether ivabradine could be effective in reducing heart rate (HR) with an acceptable safety profile in CH-HF. Methods: SHIFT was a randomized, double-blind, placebo-controlled trial in symptomatic systolic stable HF, HR ≥70 b.p.m., and in sinus rhythm. Patients treated with guideline-recommended therapy were randomized to placebo or ivabradine (starting dose 5 mg b.i.d., titrated to 7.5 mg or 2.5 mg b.i.d., according to HR and tolerability). Ivabradine significantly reduced the composite primary endpoint of cardiovascular mortality or hospitalization for worsening HF. Results: The baseline characteristics of 38 CH-HF patients versus SHIFT trial showed more prevalence of female sex, more patients in use of diuretics, cardiac glycosides, and antialdosterone agents, and fewer patients under ACEI/ARB and target daily dose of β-blocker. In the CH-HF group 20 received ivabradine and 18 placebo. Ivabradine was effective in reducing mean HR from 78±4 to 66±8 b.p.pm. (p<0.0001) versus placebo from 78.8±11 to 70±13 (p=0.03). No clinically severe bradycardia was reported with ivabradine in CH-HF patients. The primary composite end-point was reported in 50% and 56% of ivabradine and placebo group respectively (ns) (10 events in each arm). The cardiovascular mortality at 1 and 2 year follow-up was in the ivabradine group 15% and 30%, and 23% and 46% in placebo group. In the ivabradine group 90% of patients improved or persisted with the same functional class in comparison with 67% in the placebo group. Conclusions: CH-HF patients presented a high incidence of primary end-point. Ivabradine was effective in reducing HR in CH-HF patients without adverse events of severe bradycardia. Although our results are based on a very limited sample and should be interpreted with caution, they suggest that ivabradine may have a favorable benefit-risk profile in CH-HF patients.
Medicine & Science in Sports & Exercise, 1992
Clinical and Experimental Hypertension, 2021
ABSTRACT Background Systemic arterial hypertension (SAH), type 2 diabetes mellitus (T2DM), and Pa... more ABSTRACT Background Systemic arterial hypertension (SAH), type 2 diabetes mellitus (T2DM), and Parkinson’s disease (PD) are highly prevalent chronic diseases that can significantly impact the cardiovascular system. Aim The aim of this study was to compare hemodynamic and autonomic variables at rest in individuals with SAH, T2DM, or PD. Methods Fifty sedentary or insufficiently active individuals (22 men) with SAH (age = 66 ± 5.0 yr), T2DM (age = 52 ± 10 yr) or PD (age = 68 ± 8.0 yr) had their resting blood pressure (BP), arterial stiffness, endothelial function, and heart rate variability (HRV) assessed and compared. Results Systolic and diastolic BP were higher in SAH (130 ± 10 / 80 ± 10 mmHg) than T2DM (110 ± 14 / 75 ± 11 mmHg) and PD, and (123 ± 20 / 70 ± 11 mmHg) respectively. T2DM individuals showed lower arterial stiffness (8.4 ± 1.1 m/s), when compared to SAH (10.3 ± 2.3 m/s) and PD (10.6 ± 3.0 m/s). T2DM had greater resting tachycardia showed by the mean RR (759 ± 79 ms), than SAH (962 ± 169 ms) and PD (976 ± 134 ms), which was accompanied by higher sympathetic modulation (low frequency [LF]: 62 ± 19 nu) and lower parasympathetic modulation (high frequency [HF]: 32 ± 16 nu) when compared to SAH (LF: 40 ± 16 nu; HF: 61 ± 33 nu). No differences among groups were found on non-linear HRV markers and endothelial reactivity indexes. Conclusions Individuals with T2DM showed impaired levels of cardiac autonomic markers when compared to individuals with SAH and PD, despite of having lower levels of BP and arterial stiffness.
PURPOSE: Exercise oscillatory ventilation (EOV) is an abnormal breathing pattern that occurs in ~... more PURPOSE: Exercise oscillatory ventilation (EOV) is an abnormal breathing pattern that occurs in ~20% of patients with heart failure (HF) and is associated with poor prognosis and exercise intolerance. β-blockers (βb) are prescribed for most HF patients; however, their effect on EOV remains unclear. We evaluated the effect of βb on EOV in HF patients with reduced ejection fraction (HFrEF). METHODS: Fifteen patients diagnosed with HF, ejection fraction < 45%, aged from 18 to 65 years, were included before starting βb therapy. Patients underwent clinical evaluation, cardiopulmonary exercise testing, echocardiography, laboratory exams (norepinephrine levels, B type natriuretic peptide) at baseline and after βb therapy optimized for six months. Presence of exercise oscillatory breathing was determined by two experienced observers who were blinded to the moment of the test (pre or post). RESULTS: Fifteen patients (1 female), aged 49.5±2.5 years, with HFrEF, NYHA I-III enrolled in the s...
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Papers by GUILHERME VEIGA GUIMARAES