Influence of the resistance training on heart rate variability, functional capacity and muscle strength in the chronic obstructive pulmonary disease

Background. The chronic obstructive pulmonary disease (COPD) is associated with the strength and resistance decreasing in addition to the dysfunction on autonomic nervous system (ANS). The aerobic training isolated or in association with the resistance training showed evidence of beneficial effects on an autonomic modulation of COPD; however, there are no studies addressing the effect of isolated resistance training.Aims. This study aims at investigating the influence of resistance training on an autonomic modulation through heart rate variability (HRV), functional capacity and muscle strength in individuals with COPD.Design. Clinical series study.Setting. Outpatients.Population. The study involved 13 individuals with COPD.Methods. The experimental protocol was composed by an initial and final evaluation that consisted in autonomic evaluations (HRV), cardiopulmonary functional capacity evaluation (6-minute walk test) and strength evaluation (dynamometry) in addition by the resistance training performed by 24 sessions lasted 60 minutes each one and on a frequency of three times a week. The intensity was determined initially with 60% of one maximum repetition and was progressively increased in each five sessions until 80%.Results. The HRV temporal and spectral indexes analysis demonstrates improvement of autonomic modulation, with significant statistical increases to sympathetic and parasympathetic components of ANS representing by SDNN, LF and HF. In addition, it was observed significant statistical increases to shoulder abduction and. knee flexion strength and functional capacity.Conclusion. The exclusive resistance training performed was able to positively influence the autonomic modulation; in addition it promoted benefits on cardiorespiratory functional capacity and strength benefits in individuals with COPD.Clinical Rehabilitation Impact. This study could contribute to clinical and professionals researchers that act with COPD, even though the resistance component of pulmonary rehabilitation presents consensual benefits on several healthy indicators parameters. There is no evidence about the effects on HRV before. Moreover, this study showed, on clinical practice, the HRV uses as an ANS activity on sinus node evaluation and highlights further importance on scientific context.

Heart Failure-Induced Diaphragm Myopathy

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Aerobic Exercise Training Prevents Heart Failure-Induced Skeletal Muscle Atrophy by Anti-Catabolic, but Not Anabolic Actions

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Influence of N-acetylcysteine on oxidative stress in slow-twitch soleus muscle of heart failure rats

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Aerobic training attenuates nicotinic acetylcholine receptor changes in the diaphragm muscle during heart failure

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Growth hormone influences atrophy pathways in skeletal muscle of heart failure rats

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Myosin heavy chain expression and atrophy in rat skeletal muscle during transition from cardiac hypertrophy to heart failure

The purpose of this investigation was to determine whether changes in myosin heavy chain (MHC) expression and atrophy in rat skeletal muscle are observed during transition from cardiac hypertrophy to chronic heart failure (CHF) induced by aortic stenosis (AS). AS and control animals were studied 12 and 18 weeks after surgery and when overt CHF had developed in AS animals, 28 weeks after the surgery. The following parameters were studied in the soleus muscle: muscle atrophy index (soleus weight/body weight), muscle fibre diameter and frequency and MHC expression. AS animals presented decreases in both MHC1 and type I fibres and increases in both MHC2a and type IIa fibres during late cardiac hypertrophy and CHF. Type IIa fibre atrophy occurred during CHF. In conclusion, our data demonstrate that skeletal muscle phenotype changes occur in both late cardiac hypertrophy and heart failure; this suggests that attention should be given to the fact that skeletal muscle phenotype changes occur prior to overt heart failure symptoms.

Aerobic training attenuates nicotinic acethylcholine receptor changes in the diaphragm muscle during heart failure

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Exercise training prevents oxidative stress and ubiquitin-proteasome system overactivity and reverse skeletal muscle atrophy in heart failure

Background: Heart failure (HF) is known to lead to skeletal muscle atrophy and dysfunction. However, intracellular mechanisms underlying HF-induced myopathy are not fully understood. We hypothesized that HF would increase oxidative stress and ubiquitin-proteasome system (UPS) activation in skeletal muscle of sympathetic hyperactivity mouse model. We also tested the hypothesis that aerobic exercise training (AET) would reestablish UPS activation in mice and human HF. Methods/Principal Findings: Time-course evaluation of plantaris muscle cross-sectional area, lipid hydroperoxidation, protein carbonylation and chymotrypsin-like proteasome activity was performed in a mouse model of sympathetic hyperactivity-induced HF. At the 7th month of age, HF mice displayed skeletal muscle atrophy, increased oxidative stress and UPS overactivation. Moderate-intensity AET restored lipid hydroperoxides and carbonylated protein levels paralleled by reduced E3 ligases mRNA levels, and reestablished chymotrypsin-like proteasome activity and plantaris trophicity. In human HF (patients randomized to sedentary or moderate-intensity AET protocol), skeletal muscle chymotrypsin-like proteasome activity was also increased and AET restored it to healthy control subjects' levels. Conclusions: Collectively, our data provide evidence that AET effectively counteracts redox imbalance and UPS overactivation, preventing skeletal myopathy and exercise intolerance in sympathetic hyperactivity-induced HF in mice. Of particular interest, AET attenuates skeletal muscle proteasome activity paralleled by improved aerobic capacity in HF patients, which is not achieved by drug treatment itself. Altogether these findings strengthen the clinical relevance of AET in the treatment of HF.

Tricuspid Valve Injury After Heart Transplantation Due to Endomyocardial Biopsy: An Analysis of 3550 Biopsies

Introduction. Tricuspid regurgitation (TR) is the most commonly valvular dysfunction found after heart transplantation (HTx). It may be related to endomyocardial biopsy (EMB) performed for allograft rejection surveillance. Objective. This investigation evaluated the presence of tricuspid valve tissue fragments obtained during routine EMB performed after HTx and its possible effect on short-term and long-term hemodynamic status. Method. This single-center review included prospectively collected and retrospectively analyzed data. From 1985 to 2010, 417 patients underwent 3550 EMB after HTx. All myocardial specimens were reviewed to identify the presence of tricuspid valve tissue by 2 observers initially and in doubtful cases by a third observer. The echocardiographic and hemodynamic parameters were only considered for valvular functional damage analysis in cases of tricuspid tissue inadvertently removed during EMB. Results. The 417 HTx patients to 3550 EMB, including 17,550 myocardial specimens. Tricuspid valve tissue was observed in 12 (2.9%) patients corresponding to 0.07% of the removed fragments. The echocardiographic and hemodynamic parameters of these patients before versus after the biopsy showed increased TR in 2 cases (2/12; 16.7%) quantified as moderate without progression in the long term. Only the right atrial pressure showed a significant increase (P = .0420) after tricuspid injury; however, the worsening of the functional class was not significant enough in any of the subjects. Thus, surgical intervention was not required. Conclusions. Histological evidence of chordal tissue in EMB specimens is a real-world problem of relatively low frequency. Traumatic tricuspid valve injury due to EMB rarely leads to severe valvular regurgitation; only a minority of patients develop significant clinical symptoms. Hemodynamic and echocardiographic alterations are also less often observed in most patients.

RESULTS OF ULNAR NERVE NEUROTIZATION TO BICEPS BRACHII MUSCLE IN BRACHIAL PLEXUS INJURY

Objective: To evaluate the factors influencing the results of ulnar nerve neurotization at the motor branch of the brachii biceps muscle, aiming at the restoration of elbow flexion in patients with brachial plexus injury. Methods: 19 patients, with 18 men and 1 woman, mean age 28.7 years. Eight patients had injury to roots C5-C6 and 11, to roots C5-C6-C7. The average time interval between injury and surgery was 7.5 months. Four patients had cervical fractures associated with brachial plexus injury. The postoperative follow-up was 15.7 months. Results: Eight patients recovered elbow flexion strength MRC grade 4; two, MRC grade 3 and nine, MRC <3. There was no impairment of the previous ulnar nerve function. Conclusion: The surgical results of ulnar nerve neurotization at the motor branch of brachii biceps muscle are dependent on the interval between brachial plexus injury and surgical treatment, the presence of associated fractures of the cervical spine and occipital condyle, residual function of the C8-T1 roots after the injury and the involvement of the C7 root. Signs of reinnervation manifested up to 3 months after surgery showed better results in the long term. Level of Evidence: IV, Case Series.

Near-Term Fetal Hypoxia-Ischemia in Rabbits MRI Can Predict Muscle Tone Abnormalities and Deep Brain Injury

Background and Purpose-The pattern of antenatal brain injury varies with gestational age at the time of insult. Deep brain nuclei are often injured at older gestational ages. Having previously shown postnatal hypertonia after preterm fetal rabbit hypoxia-ischemia, the objective of this study was to investigate the causal relationship between the dynamic regional pattern of brain injury on MRI and the evolution of muscle tone in the near-term rabbit fetus. Methods-Serial MRI was performed on New Zealand white rabbit fetuses to determine equipotency of fetal hypoxia-ischemia during uterine ischemia comparing 29 days gestation (E29, 92% gestation) with E22 and E25. E29 postnatal kits at 4, 24, and 72 hours after hypoxia-ischemia underwent T2- and diffusion-weighted imaging. Quantitative assessments of tone were made serially using a torque apparatus in addition to clinical assessments. Results-Based on the brain apparent diffusion coefficient, 32 minutes of uterine ischemia was selected for E29 fetuses. At E30, 58% of the survivors manifested hind limb hypotonia. By E32, 71% of the hypotonic kits developed dystonic hypertonia. Marked and persistent apparent diffusion coefficient reduction in the basal ganglia, thalamus, and brain stem was predictive of these motor deficits. Conclusions-MRI observation of deep brain injury 6 to 24 hours after near-term hypoxia-ischemia predicts dystonic hypertonia postnatally. Torque-displacement measurements indicate that motor deficits in rabbits progressed from initial hypotonia to hypertonia, similar to human cerebral palsy, but in a compressed timeframe. The presence of deep brain injury and quantitative shift from hypo-to hypertonia may identify patients at risk for developing cerebral palsy. (Stroke. 2012;43:2757-2763.)