Luis Ulisses Signori

Functional electrical stimulation in the treatment of patients with chronic heart failure: a meta-analysis of randomized controlled trials.

Functional electrical stimulation (FES) produces beneficial effects in the treatment of patients with chronic heart failure (CHF), but studies carried out in these patients show small sample sizes and conflicting results. The aim of this metaanalysis was to systematically review the effect of treatment with FES compared with conventional aerobic exercise training (CA) or control group in patients with CHF. The search strategy included MEDLINE, LILACS, Physiotherapy Evidence Database and Cochrane Library. Randomized trials comparing FES versus CA or control group in the treatment of patients with CHF were included. Two reviewers independently extracted the data. Main analysis used a fixed-effects model. The search retrieved 794 articles, from which seven studies were included. Treatment with FES provided a smaller gain in peak VO2 compared with CA] − 0.74 ml/kg per min [95% confidence interval (CI): − 1.38 to − 0.10]}. There was no difference in the muscle strength [− 0.33Nm (95% CI: − 4.56 to 3.90)] and in the distance of the 6-min walk test [2.73m (95% CI: − 15.39 to 20.85)] on comparing FES with CA. An increase in peak VO2 of 2.78 ml/kg per min (95% CI: 1.44-4.13) was observed in FES versus the control group. Treatment with FES provides a similar gain in the distance of the 6-min walk test and in the muscle strength when compared with CA, but a small gain in the peak VO2. An increase in the peak VO2 can be obtained with FES as compared with the control group. Thus, FES may be an alternative in relation with CA for patients with CHF and with those who are unable to perform this kind of exercise. Eur J Cardiovasc Prev Rehabil 17:254-260

Força muscular respiratória e capacidade funcional na insuficiência renal terminal

OBJECTIVE: to evaluate the association of respiratory muscle strength with functional capacity, lower limb strength and biochemical variables in hemodialysis (HD) patients. METHODS: a cross-sectional study involving 30 patients (18 male), 53.4 ± 12.9 years, 41.1 ± 55.7 months on HD therapy. Maximal inspiratory pressure (PImax), maximal expiratory pressure (PEmax), distance completed in a six-minute walk test (6MWT) and number of repetitions in sit-and-stand test (STST) were evaluated. The biochemical variables were recorded in the database routine work service. RESULTS: LogEPmax and 6MWT values were significantly lower than the predicted values (p = 0.015; p < 0.001, respectively). logPImax and logPEmax were correlated with number of repetitions in STST (r = 0.476, p = 0.008; r = 0.540, p = 0.002, respectively) and with phosphorus blood levels (r = 0.422, p = 0.020; r = 0.639, p < 0.001, respectively). 6MWT was correlated with logPEmax (r = 0.511; p = 0.004) and with number of repetitions in STST (r = 0.561; p = 0.001). CONCLUSION: PEmax reduction in patients with ESRD on HD is associated with functional capacity, lower limb strength and phosphorus blood levels, and may at least partly represent the low physical and functional performance of these patients.

Endothelial function in patients with slow coronary flow and normal coronary angiography

Atherosclerotic heart disease usually manifests as angina and is diagnosed by stress imaging tests and coronary angiography (1), but some patients with typical angina and documented myocardial ischemia have normal coronary arteries (2), a clinical picture called cardiac syndrome X (3). Endothelial (4) and microvascular (5) dysfunction have been suggested to play a pathogenic role in this situation. Patients with slow coronary flow (SCF) (6) and endothelial dysfunction (7) are both at increased risk for cardiovascular events. Several methods to measure endothelial injury can provide clinical opportunities to identify these patients (8), but the evaluation of endothelial function in arterial and venous vascular beds has not yet been performed. The aim of this study was to evaluate the arterial and venous endothelial functions in patients with stable angina and normal coronary anatomy but SCF on a cardiac angiogram.

Effects of low frequency functional electrical stimulation with 15 and 50 Hz on muscle strength in heart failure patients

Purpose.u2003To compare the acute effects of functional electrical stimulation (FES) with 15 and 50 Hertz (Hz) frequencies on muscle strength in patients with heart failure with healthy individuals. Methods.u2003Twenty-two 61.6u2009±u20091.0 y-old male volunteers were studied: 10 patients with heart failure (functional class II-III) and 12 healthy controls. The isometric muscle peak torque (IMPT) of the quadriceps femoral muscle was measured through a Biodex dynamometer in maximum voluntary contraction (MVC), and under FES of 50u2009Hz and 15u2009Hz, which was applied with a 0.4u2009ms pulse width, 10-s contraction time, 50- s resting time and maximum tolerable intensity. Results.u2003The IMPT differed in MVC, 50u2009Hz and 15u2009Hz FES both in patients (201.9u2009±u200914, 55.6u2009±u200913 and 42.1u2009±u200912 Newton-metre, respectively; pu2009<u20090.001) and in controls (179.3u2009±u20099, 62.4u2009±u20098 and 52.3u2009±u20097 Newton-metre, respectively; pu2009<u20090.001). There were no differences between the groups. In patients and controls, respectively, the 50u2009Hz FES corresponded to 27% versus 35% and the 15u2009Hz to 21% versus 29% of the IMPT generated at the MVC (pu2009<u20090.001). Discussion.u2003This result can be attributed to the fact that muscle strength is proportional to the stimulation frequency and to the number of recruited motor units. Thus, the higher the frequency, the greater the motor recruiting, producing increased muscle strength. Conclusion.u2003The IMPT generated by acute 50u2009Hz application of FES is higher than the one generated by 15u2009Hz, but it is lower than MVC in controls and patients with heart failure.

Hemodialysis improves endothelial venous function in end-stage renal disease

The objective of the present study was to determine the acute effect of hemodialysis on endothelial venous function and oxidative stress. We studied 9 patients with end-stage renal disease (ESRD), 36.8 +/- 3.0 years old, arterial pressure 133.8 +/- 6.8/80.0 +/- 5.0 mmHg, time on dialysis 55.0 +/- 16.6 months, immediately before and after a hemodialysis session, and 10 healthy controls matched for age and gender. Endothelial function was assessed by the dorsal hand vein technique using graded local infusion of acetylcholine (endothelium-dependent venodilation, EDV) and sodium nitroprusside (endothelium-independent venodilation). Oxidative stress was evaluated by measuring protein oxidative damage (carbonyls) and antioxidant defense (total radical trapping antioxidant potential - TRAP) in blood samples. All patients were receiving recombinant human erythropoietin for at least 3 months and were not taking nitrates or a-receptor antagonists. EDV was significantly lower in ESRD patients before hemodialysis (65.6 +/- 10.5) vs controls (109.6 +/- 10.8; P = 0.010) and after hemodialysis (106.6 +/- 15.7; P = 0.045). Endothelium-independent venodilation was similar in all comparisons performed. The hemodialysis session significantly decreased TRAP (402.0 +/- 53.5 vs 157.1 +/- 28.3 U Trolox/microL plasma; P = 0.001). There was no difference in protein damage comparing ESRD patients before and after hemodialysis. The magnitude of change in the EDV was correlated negatively with the magnitude of change in TRAP (r = -0.70; P = 0.037). These results suggest that a hemodialysis session improves endothelial venous function, in association with an antioxidant effect.

Reversal of postprandial endothelial dysfunction by cyclooxygenase inhibition in healthy volunteers.

The aim of this study was to evaluate the role of cyclooxygenase (COX) in venous vascular reactivity changes after an oral lipid overload (OLO). Venous endothelial function (dorsal hand vein technique) was evaluated in fasting, 30 minutes after COX inhibition (aspirin-fasting), 2 to 4 hours after an OLO (1000 kcal, 58% fat), and again after COX inhibition (aspirin-OLO, 600 mg/200 mL water) in 10 healthy adults (age, 28.1 ± 1.3 years; body mass index, 22.3 ± 0.6 kg/m2). Fasting, 2- to 4-hour post-OLO, and 60-minute postaspirin plasma glucose, insulin, and lipids were also evaluated. The OLO increased triglycerides and insulin, reduced low-density lipoprotein and high-density lipoprotein, but glycemia and total cholesterol remained unchanged. There were no metabolic differences between OLO and aspirin-OLO. In fasting, aspirin reduced acetylcholine-induced venodilation (107.0% ± 14% versus 57.3% ± 11%; P < 0.001). Vascular reactivity was blunted after the OLO (phenylephrine dose: 0.3 ± 0.2 fasting versus 1.9 ± 0.8 nmol/min after OLO; P < 0.001) and was partially corrected by aspirin (0.4 ± 0.2; P < 0.001). Similar changes were observed in maximum venodilation after acetylcholine (107.0% ± 14% fasting versus 60.4% ± 9% after OLO, P < 0.001; aspirin-OLO: 95.9% ± 6%; P < 0.001). The responses to sodium nitroprusside remained unchanged during the study. We conclude that the OLO reduction in the endothelium-dependent venoconstriction and venodilation is partially the result of the action of COX.

Effects of Different Therapeutic Ultrasound Waveforms on Endothelial Function in Healthy Volunteers: A Randomized Clinical Trial

The purpose of this study was to determine the effects of different therapeutic 1-MHz ultrasound waveforms on endothelial function before and after cyclooxygenase (COX) inhibition. Forty-two healthy volunteers aged 27.2 ±xa03.8xa0y underwent interventions and an evaluation for endothelial function (nxa0=xa015; with COX inhibition, nxa0=xa015; duration of the vasodilator effect, nxa0=xa012) by technique flow-mediated dilation. Continuous ultrasound therapy (0.4xa0W/cm(2 SATA)), pulsed ultrasound therapy (20% duty cycle, 0.08xa0W/cm(2 SATA)) or placebo (equipment power off) was randomly applied over the brachial artery for 5xa0min. COX inhibition (aspirin) was carried out 30xa0min before treatments. In relation to the placebo, flow-mediated dilation increased by 4.8% using continuous ultrasound and by 3.4% using pulsed ultrasound. After COX, flow-mediated dilation was enhanced by 2.1% by continuous ultrasound and 2.6% by pulsed ultrasound. This vasodilation persisted for 20xa0min. Continuous and pulsed therapeutic 1-MHz ultrasound waveforms improved endothelial function in humans, which provided them with anti-inflammatory vascular effects.

Effects of different frequencies of transcutaneous electrical nerve stimulation on venous vascular reactivity

Transcutaneous electrical nerve stimulation (TENS) is a type of therapy used primarily for analgesia, but also presents changes in the cardiovascular system responses; its effects are dependent upon application parameters. Alterations to the cardiovascular system suggest that TENS may modify venous vascular response. The objective of this study was to evaluate the effects of TENS at different frequencies (10 and 100 Hz) on venous vascular reactivity in healthy subjects. Twenty-nine healthy male volunteers were randomized into three groups: placebo (n=10), low-frequency TENS (10 Hz, n=9) and high-frequency TENS (100 Hz, n=10). TENS was applied for 30 min in the nervous plexus trajectory from the superior member (from cervical to dorsal region of the fist) at low (10 Hz/200 μs) and high frequency (100 Hz/200 μs) with its intensity adjusted below the motor threshold and intensified every 5 min, intending to avoid accommodation. Venous vascular reactivity in response to phenylephrine, acetylcholine (endothelium-dependent) and sodium nitroprusside (endothelium-independent) was assessed by the dorsal hand vein technique. The phenylephrine effective dose to achieve 70% vasoconstriction was reduced 53% (P<0.01) using low-frequency TENS (10 Hz), while in high-frequency stimulation (100 Hz), a 47% increased dose was needed (P<0.01). The endothelium-dependent (acetylcholine) and independent (sodium nitroprusside) responses were not modified by TENS, which modifies venous responsiveness, and increases the low-frequency sensitivity of α1-adrenergic receptors and shows high-frequency opposite effects. These changes represent an important vascular effect caused by TENS with implications for hemodynamics, inflammation and analgesia.

Respostas metabólicas e inflamatórias após infusão de insulina para a avaliação endotelial venosa

Resumen pt: Avaliar as alteracoes no perfil lipidico, na glicose, na insulina e nos marcadores inflamatorios apos infusao endovenosa de doses de insulina usadas para...