Effect of Systemic and Auricular Acupuncture with a 2/100 Hz Frequency and Nogier Frequency in Fibromyalgia: a Randomized Clinical Trial, Pilot Study

Background

Fibromyalgia is a syndrome of chronic, generalized muscular pain, accompanied by sleep disturbances, fatigue and cardic autonomic dysfunction that will affect the quality of life. There is currently no gold standard treatment. There are limitations of studies with electroacupuncture in auricular acupuncture.

Objectives

We evaluate the effects of systemic electroacupuncture (EA) with frequencies of 2/100 Hz associated of auricular acupuncture with a Nogier frequency (2.28, 4.56 and 9.12 Hz) for pain intensity, heart rate variability (HRV), and quality of life in fibromyalgia.

Methods

Randomized clinical trial, a pilot study. Eighteen volunteers were randomized into a control group (CG, n = 9) and an experimental group (EG, n = 9). Six systemic EA sessions systemic and auricular were applied in the EG for 20 min, twice a week, for six weeks consecutive. The Numerical Pain Assessment Scale (NPRS), 2010 diagnostic criteria of the American College of Rheumatology (FDC 2010), Fibromyalgia Impact Questionnaire (FIQ) and analysis of HRV were the instruments used. The independent t-test compared to the groups was applied.

Results

There was no statistically significant difference for the primary outcome for NPRS (p > 0.05). In the secondary outcome there was a significant difference in the total score and in some FIQ domains (p = 0.008) and some variables such as pain (p = 0.02) and anxiety (p = 0.006). There was no significant difference for the FDC 2010 and HRV variables (p > 0.05).

Conclusion

2/100 Hz systemic EA associated with the Nogier frequency positively influenced some quality of life variables; however, pain intensity, diagnostic criteria, and HRV variables did not change.

Non-invasive ventilatory support accelerates the oxygen uptake and heart rate kinetics and improves muscle oxygenation dynamics in COPD-HF patients

BACKGROUND

The aim of this study was to explore the effects of non-invasive positive pressure ventilation (NIPPV) associated with high-intensity exercise on heart rate (HR) and oxygen uptake (V̇O₂) recovery kinetics in in patients with coexistence of chronic obstructive pulmonary disease (COPD) and heart failure (HF).

METHODS

This is a randomized, double blinded, sham-controlled study involving 14 HF-COPD patients, who underwent a lung function test and Doppler echocardiography. On two different days, patients performed incremental cardiopulmonary exercise testing (CPET) and two constant-work rate tests (80% of CPET peak) receiving Sham or NIPPV (bilevel mode - Astral 150) in a random order until the limit of tolerance (Tlim). During exercise, oxyhemoglobin and deoxyhemoglobin were assessed using near-infrared spectroscopy (Oxymon, Artinis Medical Systems, Einsteinweg, Netherland).

RESULTS

The kinetic variables of both V̇O₂ and HR during the high-intensity constant workload protocol were significantly faster in the NIPPV protocol compared to Sham ventilation (P<0.05). Also, there was a marked improvement in oxygenation and lower deoxygenation of both peripheral and respiratory musculature in TLim during NIPPV when contrasted with Sham ventilation.

CONCLUSIONS

NIPPV applied during high-intensity dynamic exercise can effectively improve exercise tolerance, accelerate HR and V̇O₂ kinetics, improve respiratory and peripheral muscle oxygenation in COPD-HF patients. These beneficial results from the effects of NIPPV may provide evidence and a basis for high-intensity physical training for these patients in cardiopulmonary rehabilitation programs.

Unveiling mutation effects on the structural dynamics of the main protease from SARS-CoV-2 with hybrid simulation methods

The main protease of SARS-CoV-2 (called M^pro or 3CL^pro) is essential for processing polyproteins encoded by viral RNA. Several M^pro mutations were found in SARS-CoV-2 variants, which are related to higher transmissibility, pathogenicity, and resistance to neutralization antibodies. Macromolecules adopt several favored conformations in solution depending on their structure and shape, determining their dynamics and function. In this study, we used a hybrid simulation method to generate intermediate structures along the six lowest frequency normal modes and sample the conformational space and characterize the structural dynamics and global motions of WT SARS-CoV-2 M^pro and 48 mutations, including mutations found in P.1, B.1.1.7, B.1.351, B.1.525 and B.1.429+B.1.427 variants. We tried to contribute to the elucidation of the effects of mutation in the structural dynamics of SARS-CoV-2 M^pro. A machine learning analysis was performed following the investigation regarding the influence of the K90R, P99L, P108S, and N151D mutations on the dimeric interface assembling of the SARS-CoV-2 M^pro. The parameters allowed the selection of potential structurally stable dimers, which demonstrated that some single surface aa substitutions not located at the dimeric interface (K90R, P99L, P108S, and N151D) are able to induce significant quaternary changes. Furthermore, our results demonstrated, by a Quantum Mechanics method, the influence of SARS-CoV-2 M^pro mutations on the catalytic mechanism, confirming that only one of the chains of the WT and mutant SARS-CoV-2 M^pros are prone to cleave substrates. Finally, it was also possible to identify the aa residue F140 as an important factor related to the increasing enzymatic reactivity of a significant number of SARS-CoV-2 M^pro conformations generated by the normal modes-based simulations.

Pulsed Laser Acupuncture in the Treatment of Pain and Heart Rate Variability in Fibromyalgia Patients: A Pilot Randomized Clinical Trial

Introduction: Laser acupuncture (LA) is a medically approved treatment for chronic pain, especially fibromyalgia. It is widely known that all pain is related to autonomic modulation, which may influence heart rate variability (HRV). There are robust studies in the literature on the effect of LA with continuous frequency on musculoskeletal pain and autonomic modulation. However, little is known about the effect of pulsed frequency on fibromyalgia. Therefore, this study aimed to evaluate whether an individualized intervention protocol applying pulsed LA would provide benefits related to pain symptoms and cardiac autonomic modulation in patients with fibromyalgia. Methods: In this pilot randomized clinical controlled trial, the sample consisted of women with fibromyalgia between the ages of 40 and 80, randomized into two groups: a control group (CG; n=10) and an experimental group (EG; n=10). EG received the intervention twice per week for 3 weeks. Statistical analysis was conducted by delta (difference between post-intervention and pre-intervention) and the Shapiro-Wilk test (normality). For comparison between the groups, the Mann-Whitney test was used. Results: The results showed a significant reduction in pain intensity as reported via the pain numerical scale (PNS; P=0.00), generalized pain index (GPI; P=0.00), and symptom severity scale (SSS; P=0.00). There was no significant difference in any HRV variable (P>0.05). Conclusion: Pulsed LA, when applied in an individualized protocol, can reduce pain intensity, as reported on the PNS, GPI, and SSS. However, no therapeutic effect was observed for HRV.

Effects of Aging on Hemodynamic Kinetics in Different Intensities of Dynamic Exercise

Healthy aging hemodynamics is known to exhibit a time-dependent loss of function. We aimed at verifying whether older men would have a slowed cardiac output and stroke volume dynamics in response to the onset ("on") and on recovery ("off") of exercise in comparison to young men. Twenty healthy active men (10 young and 10 older) were recruited. Participants performed an incremental cardiopulmonary exercise testing on a cycle ergometer, and on another day, 3 constant workload tests in different intensities. Compared to younger, older men exhibited a slower cardiac output and stroke volume dynamics in both on and off transients for all exercise intensities (all P < 0.05). During higher intensities, both younger and older men had slower hemodynamic kinetics compared to lower intensities (all P < 0.05). There was strong negative relationship between the time constant of cardiac output on-kinetics during high-intensity with maximal exercise performance in both groups (r = -0.88, P < 0.01). We interpret these findings to mean that healthy older men have slowed hemodynamic kinetics compared to younger, but this difference becomes less evident in higher intensities of exercise.

Brain-heart autonomic axis across different clinical status and severity of chronic obstructive pulmonary disease

PURPOSE

Impairment of cardiac autonomic integrity is common in chronic obstructive pulmonary disease (COPD) patients. The influence of the interaction between clinical and severity status on brain-heart autonomic axis (BHAA) is not well known. We aimed to investigate the BHAA function across different clinical status and severity of COPD.

METHODS

Cross-sectional study involving 77 COPD patients allocated into four groups according to clinical status [acute exacerbation (GAE) or stable (GST)] and severity [less (-) or more (+)]: 1) GAE-, n = 13; 2) GAE+, n = 20; 3) GST-, n = 23; and 4) GST+, n = 21. Heart rate variability (HRV) at rest and heart rate recovery (HRR) after 6-min walk test were markers of BHAA. Mean R-R, STDRR, RMSSD, RRtri, HF, LF, SD1, SD2, ApEn and SampEn were the HRV indexes and, HRR was obtained as: HR at 1st min of recovery minus peak HR.

RESULTS

A main effect of clinical status (p < 0.001) was found to vagal modulation in GAE-vs. GST- (RMSSD: 25.0 ± 14.8 vs. 12.6 ± 5.5 ms; SD1: 18.0 ± 10.6 vs. 8.9 ± 3.9 ms) and to GAE + vs. GST+ (RMSSD: 26.4 ± 15.2 vs. 15.4 ± 6.3 ms; SD1: 18.3 ± 11.2 vs. 10.9 ± 4.5 ms). An effect of clinical status (p = 0.032) and severity (p = 0.030) were found to HF (vagal) in GAE + compared to GAE- and GST+ (264.7 ± 239.0 vs. 134.7 ± 169.7 and 135.8 ± 139.7 ms²). Lower HRR was found in GAE-compared to GST- (8.0 ± 2.4 vs. 19.6 ± 2.4 bpm), p = 0.002.

CONCLUSION

In COPD patients, clinical status (AECOPD or stable) was more dominant than the severity on BHAA function. A more pronounced parasympathetic modulation was found in AECOPD patients with a lower HRR to exercise.

Arterial stiffness in type 2 diabetes: determinants and indication of a discriminative value

OBJECTIVES

To identify the clinical discriminative value and determinants of arterial stiffness in individuals with type 2 diabetes mellitus (T2DM).

METHODS

This prospective cohort study included 51 individuals (53.57±9.35 years) diagnosed with T2DM (stage glucose≥126 mg/dL; diagnostic time: 87.4±69.8 months). All participants underwent an initial evaluation of personal habits, medications, and history; arterial stiffness assessment by carotid-femoral pulse wave velocity (cfPWV) using SphygmoCor; and blood laboratory analysis. A statistical analysis was performed using SPSS software, and values of p≤0.05 were considered significant.

RESULTS

A cut-off cfPWV value of 7.9 m/s was identified for T2DM [Sensitivity (SE): 90% and Specificity (SP): 80%]. A subgroup analysis revealed higher glycated hemoglobin (Hb1Ac) (p=0.006), obesity (p=0.036), and dyslipidemia (p=0.013) than those with cfPWV ≥7.9 m/s. Multivariate analysis identified higher stage glucose (p=0.04), Hb1Ac (p=0.04), hypertension (p=0.001), and dyslipidemia (p=0.01) as determinant factors of cfPWV; positive and significant correlation between cfPWV and glucose (r=0.62; p=0.0003) and Hb1Ac (r=0.55; p=0.0031).

CONCLUSIONS

In T2DM, an indicator of the discriminative value of arterial stiffness was cfPWV of 7.9 m/s. Clinical findings and comorbidities, such as hypertension, glucose, poor glycemic control, and dyslipidemia, were associated with and were determinants of arterial stiffness in T2DM. Reinforcement of monitoring risk factors, such as hypertension, dyslipidemia, and glycemic control, seems to be essential to the process of arterial stiffening. Confirmation of this discriminative value in larger populations is recommended.

Circulatory and ventilatory power in diabetic patients: Secondary analysis of a randomized controlled trial

BACKGROUND

Circulatory (CP) and ventilatory power (VP) have been used to improve the prognostic accuracy of cardiopulmonary exercise tests in cardiovascular disease, such as coronary artery disease. However, the effects of combined resistance and aerobic exercise program on VP and CP, especially in type 2 diabetes patients, have not been adequately investigated. Thus, this new parameter can be useful to prescribe exercise programs more assertive for this population. The present study aimed to assess the effect of 3 months of combined resistance and aerobic exercise training (CET) on CP and VP in patients with type 2 diabetes.

METHODS

A randomized controlled trial was conducted involving 48 diabetic patients with an average age of 52.4 (±8.01) years old. The subjects were randomized into two groups: sedentary (SG, n = 15) and the CET group (n = 19). Cardiopulmonary exercise testing (symptom-limited incremental) was performed on a cycle ergometer, and the following parameters were measured: relative VO₂ , V_E /VCO₂ slope, linear relationship between oxygen uptake and minute ventilation, and VCO₂ . CET was performed with 30-min aerobic and 30-min resistance exercises three times a week for 12 weeks.

RESULTS

Significant (p < .05) and clinical (d ≥ .80) differences were observed that favoured CET compared with SG for the following variables: heart rate, workload, VO₂ relative peak, circulatory power peak, and VCO₂ peak. Although no statistical difference was observed for ventilatory power, there was a clinical difference (p > .05 and d ≥ 0.80) that favoured CET.

CONCLUSION

Three months of combined exercise training improved VP and CP indices in patients with type 2 diabetes when compared with a sedentary group.

Cardiovascular responses to low-intensity isometric handgrip exercise in coronary artery disease: effects of posture

BACKGROUND

Coronary artery disease (CAD) lead to cardiovascular autonomic control disfunctions that can worsen exercise and/or posture adjustments.

OBJECTIVES

To verify the cardiovascular responses to low-intensity isometric handgrip exercise performed in different postures in CAD patients. This study tested the hypothesis that the posture influences the cardiovascular responses during isometric handgrip exercise and that the presence of CAD leads to greater cardiovascular stress during this type of exercise.

METHODS

We investigated cardiovascular responses to isometric handgrip exercise in 15 CAD patients (CADG) and 15 health matched-control (CG). The subjects performed isometric handgrip exercise at 30% of maximum voluntary contraction until exhaustion in SUPINE, SITTING and STANDING positions. Systolic arterial pressure, diastolic arterial pressure, mean blood pressure, heart rate, peripheral vascular resistance, cardiac output, stroke volume and double product were measured during rest (baseline), exercise (peak value) and recovery in the 1st minute (REC1). Delta PB (ΔPB, peak minus baseline) and PR1 (ΔPR1, peak minus REC1) were calculated.

RESULTS

Higher ΔPB and ΔPR1 of systolic and mean arterial pressure and double product were observed in STANDING when compared to SITTING and/or SUPINE. CADG showed higher ΔPB of systolic and mean arterial pressure in all postures and higher ΔPR1 of strove volume in the SITTING.

CONCLUSION

We concluded that the posture during isometric handgrip exercise influences the cardiovascular responses with STANDING leading to higher cardiovascular stress. CAD promoted higher arterial pressure responses however these responses were physiological and expected due to the presence of disease and type of exercise.

The additional impact of type 2 diabetes on baroreflex sensitivity of coronary artery disease patients might be undetectable in presence of deterioration of mechanical vascular properties

Both deterioration of the mechanical vascular properties of barosensitive vessels and autonomic derangement lead to modification of baroreflex sensitivity (BRS) in coronary artery disease (CAD) individuals. Type 2 diabetes (T2D) reduces BRS as well even in absence of cardiac autonomic neuropathy. The aim of the study is to clarify whether, assigned the degree of mechanical vascular impairment and without cardiac autonomic neuropathy, the additional autonomic dysfunction imposed in CAD patients by T2D (CAD-T2D) decreases BRS further. We considered CAD (n = 18) and CAD-T2D (n = 19) males featuring similar increases of average carotid intima media thickness (ACIMT) and we compared them to age- and gender-matched healthy (H, n = 19) subjects. BRS was computed from spontaneous beat-to-beat variability of heart period (HP) and systolic arterial pressure (SAP) at supine resting (REST) and during active standing (STAND). BRS was estimated via methods including time domain, spectral, cross-spectral, and model-based techniques. We found that (i) at REST BRS was lower in CAD and CAD-T2D groups than in H subjects but no difference was detected between CAD and CAD-T2D individuals; (ii) STAND induced an additional decrease of BRS visible in all the groups but again BRS estimates of CAD and CAD-T2D patients were alike; (iii) even though with different statistical power, BRS markers reached similar conclusions with the notable exception of the BRS computed via model-based approach that did not detect the BRS decrease during STAND. In presence of a mechanical vascular impairment, indexes estimating BRS from spontaneous HP and SAP fluctuations might be useless to detect the additional derangement of the autonomic control in CAD-T2D without cardiac autonomic neuropathy compared to CAD, thus limiting the applications of cardiovascular variability analysis to typify CAD-T2D individuals. Graphical abstract Graphical representation of the baroreflex sensitivity (BRS) estimated from spontaneous fluctuations of heart period and systolic arterial pressure via transfer function (TF) in low frequency (LF) band (from 0.04 to 0.15 Hz). BRS was reported as a function of the group (i.e., healthy (H), coronary artery disease (CAD) and CAD with type 2 diabetes (CAD-T2D) groups) at REST (black bars) and during STAND (white bars). Values are shown as mean plus standard deviation. The symbol "*" indicates a significant difference between conditions within the same group (i.e., H, CAD, or CAD-T2D) and the symbol "§" indicates a significant difference between groups within the same experimental condition (i.e., REST or STAND). BRS cannot distinguish CAD and CAD-T2D groups both at REST and during STAND, while it is useful to distinguish experimental conditions and separate pathological groups from H subjects.

Can high-intensity interval training change cardiac autonomic control? A systematic review

BACKGROUND

High intensity interval training (HIIT) has been used as a cardiovascular exercise strategy to promote greater adherence in cardiovascular rehabilitation. However, little is known about the effect of this training modality on cardiac autonomic control.

OBJECTIVE

To perform a systematic review to evaluate the effects of HIIT on cardiac autonomic responses in humans.

METHODS

PEDro, SCOPUS and PubMed were searched from the inception to March 29th, 2018. Moreover, the methodological quality and statistical reporting from all eligible clinical trials were assessed by the PEDro scale. The articles were eligible if: The primary objective was related to the effects of HIIT on the cardiac autonomic nervous system. Outcomes evaluated were indirect measures of cardiac autonomic control, represented by HRV indexes.

RESULTS

The search strategies resulted in 339 citations and 2 additional citations were identified through other sources. After deleting the duplicate articles and revising the full text, 6 articles were included. Overall, the results showed an improvement in parasympathetic and/or sympathetic modulation after HIIT, when evaluated by linear and non-linear indexes of HRV.

CONCLUSIONS

HIIT is a promising tool to improve the cardiac autonomic control, with more recommendation in healthy individuals and patients with metabolic syndrome.

High-Intensity Inspiratory Protocol Increases Heart Rate Variability in Myocardial Revascularization Patients

Objective:

To evaluate heart rate variability during an inspiratory muscle endurance protocol at three different load levels [30%, 60% and 80% of maximal inspiratory pressure], in patients who had previously undergone coronary artery bypass grafting.

Methods:

Nineteen late postoperative myocardial revascularization patients participating in a cardiovascular rehabilitation program were studied. Maximal inspiratory pressure maneuvers were performed. An inspiratory muscle endurance protocol at 30%, 60% and 80% of maximal inspiratory pressure was applied for four minutes each, in random order. Heart rate and RR intervals were recorded and heart rate variability was analyzed by time (RMSSD-the mean of the standard deviations for all R-R intervals, and RMSM-root-mean square differences of successive R-R intervals) and frequency domains indices (high and low frequency) in normalized units. ANOVA for repeated measurements was used to compare heart rate variability indices and Student t-test was used to compare the maximal inspiratory pressure and maximal expiratory pressure values.

Results:

Heart rate increased during performance of maximal respiratory pressures maneuvers, and the maximal inspiratory pressure and maximal expiratory pressure mean values were significantly lower than predicted values (P<0.05). RMSSD increased significantly at 80% in relation to rest and 30% of maximal inspiratory pressure and RMSM decreased at 30% and 60% of maximal inspiratory pressure in relation to rest (P<0.05). Additionally, there was significant and progressive decrease in low frequency and increase in high frequency at 30%, 60% and 80% of maximal inspiratory pressure in relation to the resting condition.

Conclusion:

These results suggest that respiratory muscle training at high intensities can promote greater parasympathetic activity and it may confer important benefits during a rehabilitation program in post-coronary artery bypass grafting.

Heart rate variability and surface electromyography of trained cyclists at different cadences

<p class="ResumoAbstract">The heart rate variability (HRV) and surface electromyography (sEMG) are important tools in the evaluation of cardiac autonomic system and neuromuscular parameters, respectively. The aim of the study was to evaluate the behavior of HRV and sEMG of the vastus lateralis in two exercise protocols on a cycle ergometer at 60 and 80 rpm. Eight healthy men cyclists who have trained for at least two years were evaluated. Reduction was observed followed by stabilization of RMSSD and SDNN indices of HRV (p&lt;0.05) along with increases in the amplitude of the sEMG signal (p&lt;0.05) in both protocols. Significant correlations were observed between the responses of HRV and sEMG in the cadence of 60 rpm (RMSSD and sEMG: r = -0.42, p=0.03; SDNN and sEMG: r = -0.45, p=0.01) and 80 rpm (RMSSD and sEMG: r = -0.47, p=0.02; SDNN and sEMG: r = -0.49, p=0.01), yet no difference was observed for these variables between the two protocols. We concluded that the parasympathetic cardiac responses and sEMG are independent of cadences applied at the same power output.</p>

Circulatory and Ventilatory Power: Characterization in Patients with Coronary Artery Disease

Background

Circulatory power (CP) and ventilatory power (VP) are indices that have been used for the clinical evaluation of patients with heart failure; however, no study has evaluated these indices in patients with coronary artery disease (CAD) without heart failure.

Objective

To characterize both indices in patients with CAD compared with healthy controls.

Methods

Eighty-seven men [CAD group = 42 subjects and healthy control group (CG) = 45 subjects] aged 40–65 years were included. Cardiopulmonary exercise testing was performed on a treadmill and the following parameters were measured: 1) peak oxygen consumption (VO₂), 2) peak heart rate (HR), 3) peak blood pressure (BP), 4) peak rate-pressure product (peak systolic HR x peak BP), 5) peak oxygen pulse (peak VO₂/peak HR), 6) oxygen uptake efficiency (OUES), 7) carbon dioxide production efficiency (minute ventilation/carbon dioxide production slope), 8) CP (peak VO₂ x peak systolic BP) and 9) VP (peak systolic BP/carbon dioxide production efficiency).

Results

The CAD group had significantly lower values for peak VO₂ (p < 0.001), peak HR (p < 0.001), peak systolic BP (p < 0.001), peak rate-pressure product (p < 0.001), peak oxygen pulse (p = 0.008), OUES (p < 0.001), CP (p < 0.001), and VP (p < 0.001) and significantly higher values for peak diastolic BP (p = 0.004) and carbon dioxide production efficiency (p < 0.001) compared with CG. Stepwise regression analysis showed that CP was influenced by group (R² = 0.44, p < 0.001) and VP was influenced by both group and number of vessels with stenosis after treatment (interaction effects: R² = 0.46, p < 0.001).

Conclusion

The indices CP and VP were lower in men with CAD than healthy controls.

Recovery of linear and nonlinear heart rate dynamics after coronary artery bypass grafting surgery

BACKGROUND

Conventional coronary artery bypass grafting (C-CABG) and off-pump CABG (OPCAB) surgery may produce different patients' outcomes, including the extent of cardiac autonomic (CA) imbalance. The beneficial effects of an exercise-based inpatient programme on heart rate variability (HRV) for C-CABG patients have already been demonstrated by our group. However, there are no studies about the impact of a cardiac rehabilitation (CR) on HRV behaviour after OPCAB. The aim of this study is to compare the influence of both operative techniques on HRV pattern following CR in the postoperative (PO) period.

METHODS

Cardiac autonomic function was evaluated by HRV indices pre- and post-CR in patients undergoing C-CABG (n = 15) and OPCAB (n = 13). All patients participated in a short-term (approximately 5 days) supervised CR programme of early mobilization, consisting of progressive exercises, from active-assistive movements at PO day 1 to climbing flights of stairs at PO day 5.

RESULTS

Both groups demonstrated a reduction in HRV following surgery. The CR programme promoted improvements in HRV indices at discharge for both groups. The OPCAB group presented with higher HRV values at discharge, compared to the C-CABG group, indicating a better recovery of CA function.

CONCLUSION

Our data suggest that patients submitted to OPCAB and an inpatient CR programme present with greater improvement in CA function compared to C-CABG.

Identification of anaerobic threshold by analysis of heart rate variability during discontinuous dynamic and resistance exercise protocols in healthy older men

The purposes of this study were to determine anaerobic threshold (AT) during discontinuous dynamic and resistive exercise protocols by analysing of heart rate variability (HRV) and blood lactate (BL) in healthy elderly subjects and compare the cardiovascular, metabolic and autonomic variables obtained from these two forms of exercise. Fourteen elderly (70 ± 4 years) apparently healthy males underwent the following tests: (i) incremental ramp test on cycle ergometer, (ii) one repetition maximum (1RM) leg press at 45°, (iii) a discontinuous exercise test on a cycle ergometer (DET-C) protocol and (iv) a resistance exercise leg press (DET-L) protocol. Heart rate, blood pressure and BL were obtained during each increment of exercise intensity. No significant differences (P>0·05) were found between methods of AT determination (BL and HRV) nor the relative intensity corresponding to AT (30% of maximum intensity) between the types of exercise (DET-C and DET-L). Furthermore, no significant differences (P>0·05) were found between the DET-C and DET-L in relation to HRV, however, the DET-L provided higher values of systolic blood pressure and BL (P<0·05) from the intensity corresponding to AT. We conclude that HRV was effective in determination of AT, and the parasympathetic modulation responses obtained during dynamic and resistive exercise protocols were similar when compared at the same relative intensity. However, DET-L resulted in higher values of blood pressure and BL at workloads beyond AT.

Is applying the same exercise-based inpatient program to normal and reduced left ventricular function patients the best strategy after coronary surgery? A focus on autonomic cardiac response

PURPOSE

To assess whether the same exercise-based inpatient program applied to patients with normal and reduced left ventricular function (LVF) evokes a similar cardiac autonomic response after coronary artery bypass graft (CABG).

METHOD

Forty-four patients post-CABG, subgrouped according to normal LVF [LVFN: n = 23; left ventricular ejection fraction (LVEF) ≥ 55%] and reduced LVF (LVFR: n = 21; LVEF 35-54%), were included. All initiated the exercise protocol on post-operative day 1 (PO1), following a whole progressive program until discharge. Cardiac autonomic response was assessed by the indices of heart rate variability (HRV) at rest and during exercise (extremity range of motion and ambulation).

RESULTS

During ambulation, lower values of HRV indices were found in the LVFR group compared with the LVFN group [standard deviation of all RR (STDRR; 6.1 ± 2.7 versus 8.9 ± 4.7 ms), baseline width of the RR histogram (TINN; 30.6 ± 14.8 versus 45.8 ± 24.9 ms), SD2 (14.8 ± 8.0 versus 21.3 ± 9.0 ms), Shannon entropy (3.6 ± 0.5 versus 3.9 ± 0.4) and correlation dimension (0.08 ± 0.2 versus 0.2 ± 0.2)]. Also, when comparing the ambulation to rest change, lower values were observed in the LVFR group for linear (STDRR, TINN, RR TRI, rMSSD) and non-linear (SD2 and correlation dimension) HRV indices (p < 0.05). On PO1, we observed only intra-group differences between rest and exercise (extremity range of motion), for mean intervals between heart beats and heart rate.

CONCLUSION

For patients with LVFN, the same inpatient exercise protocol triggered a more attenuated autonomic response compared with patients with LVFR. These findings have implications as to how exercise should be prescribed according to LVF in the early stages following recovery from CABG. Implications for Rehabilitation Exercise-based inpatient program, performed by post-CABG patients who have normal left ventricular function, triggered a more attenuated cardiac autonomic response compared with patients with reduced left ventricular function. Volume of the inpatient exercises should be prescribed according to the left ventricular function in the early stages following recovery from CABG.

Effects of aerobic exercise training on variability and heart rate kinetic during submaximal exercise after gastric bypass surgery--a randomized controlled trial

BACKGROUND

This study aimed to determine whether morbidly obese women have an alteration of heart rate (HR) kinetics and HR variability (HRV) during the 6-min walk test (6MWT) and if an aerobic exercise training can modify these indexes after gastric bypass surgery (GBS).

DESIGN AND METHODS

Nineteen morbidly obese women were randomized to a trained (TG) or control group and 12 women of eutrophic group (EG) were also evaluated. The obese women were tested on two occasions: 1 week before and 4 months after GBS through record of HR and R-R intervals during 6MWT for analysis HR kinetics. The TG underwent an aerobic exercise training program on a treadmill (1-h session, totaling 36 sessions over 12-week).

RESULTS

Both obese groups demonstrated a significant reduction of rMSSD and slower HR kinetics during the 6MWT when compared to the EG. In addition, only the TG demonstrated a significant improvement in HRV indexes, walking distance, faster time constant and mean response time of HR during 6MWT after training (p < 0.05).

CONCLUSION

Morbidly obese women have slower HR kinetics and altered cardiac modulation during submaximal exercise. However, aerobic exercise training can produce beneficial adaptations in HRV and faster HR kinetics following GBS.

Metabolic and cardiac autonomic effects of high-intensity resistance training protocol in Wistar rats

The aim of this study was to assess the effects of metabolic and autonomic nervous control on high-intensity resistance training (HRT) as determined by pancreatic glucose sensitivity (GS), insulin sensitivity (IS), blood lactate ([La]), and heart rate variability (HRV) in rats. Thirty male, albino Wistar rats (292 ± 20 g) were divided into 3 groups: sedentary control (SC), low-resistance training (LRT), and HRT. The animals in the HRT group were submitted to a high-resistance protocol with a progressively increasing load relative to body weight until exhaustion, whereas the LRT group performed the same exercise regimen with no load progression. The program was conducted 3 times per week for 8 weeks. The [La], parameters related to the functionality of pancreatic tissue, and HRV were measured. There was a significant increase in peak [La] only in the HRT group, but there was a reduction in [La] when corrected to the maximal load in both trained groups (LRT and HRT, p < 0.05). Both trained groups exhibited an increase in IS; however, compared with SC and LRT, HRT demonstrated a significantly higher GS posttraining (p < 0.05). With respect to HRV, the low-frequency (LF) band, in milliseconds squared, reduced in both trained groups, but the high-frequency band, in milliseconds squared and nu, increased, and the LF in nu, decreased only in the HRT group (p < 0.05). The HRT protocol produced significant and beneficial metabolic and cardiac autonomic adaptations. These results provide evidence for the positive benefits of HRT in counteracting metabolic and cardiovascular dysfunction.

Impact of aerobic exercise training on heart rate variability and functional capacity in obese women after gastric bypass surgery

BACKGROUND

Obesity is a major public health concern on a global scale. Bariatric surgery is among the treatment options, resulting in significant and sustainable weight loss as well as amelioration of comorbidities. The purpose of this study was to evaluate whether a 12-week aerobic exercise program positively impacts heart rate variability (HRV) and functional capacity after gastric bypass surgery (GBS) in a female cohort.

METHODS

Of the 52 patients initially recruited, 21 were randomized to a training group (TG) or control group and successfully completed the study. Patients were tested on two occasions: 1 week before GBS and 4 months after GBS. Anthropometric variables, body composition, record of heart rate and R-R intervals, and 6-min walk test (6MWT) were assessed at both time points. The TG underwent an aerobic exercise training program on a treadmill (1-h session, totaling 36 sessions over 12 weeks).

RESULTS

The main findings from this study were: (1) only the TG demonstrated a significant increase (p < 0.05) in all indexes of heart rate variability (HRV) after 12 weeks of aerobic exercise training and (2) only the TG demonstrated a significant increase (p < 0.05) in 6MWT distance and decrease in diastolic blood pressure after aerobic exercise training.

CONCLUSIONS

We conclude that 12 weeks of aerobic exercise training improves cardiac autonomic modulation and functional capacity 4 months after GBS.

MMP(-2) expression in skeletal muscle after strength training

The aim of this study was to assess the effects of resistance training on ladders (RTL) on MMP(-2) expression and blood lactate concentration [La-]. 30 male (3 months of age), albino rats were divided into 3 groups: sedentary control (SC, n=10), low resistance exercise training (Low-IntRT, n=10) and high-intensive exercise training (High-IntRT, n=10). Animals of High-IntRT were submitted to a progressively increasing overload in relation to body weight until exhaustion, while the Low-IntRT group performed the same exercise regimen with no external load. The program had a frequency of 3 times per week over 8 weeks. MMP(-2) expression of tibialis anterior muscle and [La-] were measured. While there was a significant increase of MMP(-2) (pro-form) in both groups, only High-IntRT significantly increased MMP(-2) in active-form (p<0.05). Both trained groups exhibited an increase in [La-] when compared to controls, however, the increase in [La-] was significantly higher in the High-IntRT compared to Low-IntRT (p<0.05). Strong correlation was found between MMP(-2) (active form) and [La-] in High-IntRT (r=0.91). RTL in using low and high-intensity exercise can serve as a model to demonstrate different responses of MMP(-2) expression in an animal model. It appears active form expression of MMP(-2) is modulated by exercise intensity.

Cardiac autonomic modulation during progressive upper limb exercise by patients with coronary artery disease

The purpose of this study was to investigate the behavior of heart rate (HR) and HR variability (HRV) during different loads of resistance exercise (incline bench press) in patients with coronary artery disease (CAD) and healthy sedentary controls. Ten healthy men (65 ± 1.2 years, control group, CG) and 10 men with clinically stable CAD (66 ± 2.4 years, CADG) were recruited. A discontinuous progressive protocol was applied with an initial load of 10% of the maximum load achieved in the 1RM (1 repetition maximum) with increases of 10% until 30% 1RM was reached, which was followed by subsequent increases of 5% 1RM until exhaustion. HRV was analyzed by linear and non-linear methods. There was a significant reduction in rMSSD (CG: 20 ± 2 to 11 ± 3 ms; CADG: 19 ± 3 to 9 ± 1 ms) and SD1 indexes (CG: 14 ± 2 to 8 ± 1 ms; CADG: 14 ± 2 to 7 ± 1 ms). An increase in HR (CG: 69 ± 5 to 90 ± 5 bpm; CADG: 62 ± 4 to 75 ± 4 bpm) and in systolic blood pressure (CG: 124 ± 3 to 138 ± 3 mmHg; CADG: 122 ± 6 to 126 ± 9 bpm) were observed (P < 0.05) when comparing pre-effort rest and 40% 1RM in both groups. Furthermore, an increase in RMSM index was also observed (CG: 28 ± 3 to 45 ± 9 ms; CADG: 22 ± 2 to 79 ± 33 ms), with higher values in CADG. We conclude that loads up to 30% 1RM during incline bench press result in depressed vagal modulation in both groups, although only stable CAD patients presented sympathetic overactivity at 20% 1RM upper limb exercise.

Deep breathing heart rate variability is associated with respiratory muscle weakness in patients with chronic obstructive pulmonary disease

BACKGROUND

A synchronism exists between the respiratory and cardiac cycles. However, the influence of the inspiratory muscle weakness in chronic obstructive pulmonary disease (COPD) on cardiac autonomic control is unknown. The purpose of the present investigation was to evaluate the influence of respiratory muscle strength on autonomic control in these patients.

METHODS

Ten chronic obstructive pulmonary disease patients (69+/-9 years; FEV(1)/FVC 59+/-12% and FEV(1) 41+/-11% predicted) and nine age-matched healthy volunteers (64+/-5 years) participated in this study. Heart-rate variability (HRV) was obtained at rest and during respiratory sinusal arrhythmia maneuver (RSA-M) by electrocardiograph.

RESULTS

Chronic obstructive pulmonary disease patients demonstrated impaired cardiac autonomic modulation at rest and during RSA-M when compared with healthy subjects (p<0.05). Moreover, significant and positive correlations between maximal inspiratory pressure (MIP) and the inspiratory-expiratory difference (DeltaIE) (r = 0.60, p<0.01) were found.

CONCLUSION

Patients with chronic obstructive pulmonary disease presented impaired sympathetic-vagal balance at rest. In addition, cardiac autonomic control of heart rate was associated with inspiratory muscle weakness in chronic obstructive pulmonary disease. Based on this evidence, future research applications of respiratory muscle training may bring to light a potentially valuable target for rehabilitation.

Aerobic exercise training improves autonomic nervous control in patients with COPD

OBJECTIVES

Autonomic modulation is adversely impacted in patients with chronic obstructive pulmonary disease (COPD). The purpose of the present investigation is to assess the effects of a 6-week aerobic exercise training program on autonomic modulation of heart rate in patients with COPD.

METHODS

Forty patients of both sexes with moderate-to-severe COPD were randomly allocated to aerobic exercise training (PT, n=20) or to usual care (Control, n=20). The training program consisted of lower and upper limb stretching and 30 min of treadmill exercise, 3 times per week for a 6-week period. Physiological data during symptom-limited exercise testing and the six-minute walk test (6MWT) were assessed. In addition, R-R intervals were obtained at rest and during the 6MWT. Heart rate variability was analyzed by time (rMSSD and SDNN index) and frequency domains (high frequency--HF, low frequency--LF and HF/LF ratio).

RESULTS

Peak oxygen consumption significantly improved in the training group only (p<0.05). Moreover, the training group demonstrated significant improvements (p<0.05) in blood lactate, minute ventilation, dyspnea at peak exercise, sympathetic activity, and parasympathetic activity at rest and during submaximal exercise. Lastly, a positive and significant correlation was found between change in 6MWT distance and rMSSD index (r=0.65 and p=0.001).

CONCLUSIONS

Neural control of heart rate, in addition to other clinically valuable measures, is positively altered in moderate-severe COPD patients following 6 weeks of aerobic exercise training. The improvement in submaximal performance after exercise training was associated with parasympathetic activity.

Prevalence of reduced respiratory muscle strength in institutionalized elderly people

CONTEXT AND OBJECTIVES

Respiratory muscle strength is relevant to the clinical situation of elderly patients, particularly those presenting with respiratory or cardiac diseases. The objectives of this study were to evaluate the respiratory muscle strength of institutionalized elderly women, compare this with predicted values for the Brazilian population and calculate the correlation with age and anthropometric characteristics.

DESIGN AND SETTING

Cross-sectional study at the Department of Physiotherapy of Universidade Camilo Castelo Branco.

METHODS

The participants were 56 institutionalized elderly women (74.87 +/- 10.55 years of age), evaluated in eight institutions in three cities in the central region of the State of São Paulo, between January 2005 and March 2006. They were separated into three subgroups according to age: 60-69 years (n = 20), 70-79 (n = 18) and 80-89 years (n = 18). Maximal respiratory pressures were obtained using a manovacuometer. The values obtained were compared between subgroups and with predicted values. Correlation analysis was used to evaluate age, weight, height and body mass index in relation to maximal respiratory pressures. The significance level was P < 0.05.

RESULTS

No significant differences in maximal respiratory pressures were seen between the three subgroups. The maximal respiratory pressures were significantly lower in the three subgroups, compared with predicted values. Negative correlations between maximal respiratory pressures and age and positive correlations in relation to weight, height and body mass index were found.

CONCLUSIONS

Respiratory muscle strength was markedly reduced in institutionalized 60 to 89-year-old women and the values demonstrated correlations with age and anthropometric characteristics.

Noninvasive ventilation acutely modifies heart rate variability in chronic obstructive pulmonary disease patients

OBJECTIVE

The purpose of present study was to evaluate the acute effects of bi-level positive airway pressure (BiPAP) on heart rate variability (HRV) of stable chronic obstructive pulmonary disease patients (COPD).

METHODS

Nineteen males with COPD (69+/-8 years and with forced expiratory volume in 1s <50% of predicted) and eight healthy sedentary age-matched (69 years) males in the control group (CG) were evaluated during two conditions of controlled respiratory rate: spontaneous breathing (SB) and BiPAP (inspiratory and expiratory levels between 12-14 cmH(2)O and 4-6 cmH(2)O, respectively). Peripheral oxygen saturation (SpO(2)), end-tidal of carbon dioxide (ETCO(2)), systolic blood pressure (SBP) and R-R interval were obtained. HRV was analyzed by time (RMSSD and SDNN index) and frequency domains (high frequency - HF, low frequency - LF and HF/LF ratio).

RESULTS

Significant reduction of ETCO(2) and SBP in both groups and increase of SpO(2) in COPD group was observed during BiPAP ventilation (p<0.05). During spontaneous breathing, patients with COPD presented lower values of LF, LF/HF and higher values of HF when compared to CG (p<0.05). However, HF was significantly reduced and LF increased during BiPAP ventilation (58+/-19-48+/-15 and 41+/-19-52+/-15 un, respectively) in COPD group. Significant correlations between delta BiPAP-SB (Delta) ETCO(2) and DeltaHF were found (r=0.89).

CONCLUSIONS

Sympathetic and parasympathetic neural control of heart rate is altered in COPD patients and that BiPAP acutely improves ventilation, enhances sympathetic response and decreases vagal tonus. The improvement of ventilation caused by BiPAP was associated with reduced cardiac vagal activity in stable moderate-to-severe COPD patients.

Comparative bioavailability of clarithromycin formulations in healthy Brazilian volunteers

OBJECTIVE

To compare the bioavailability of clarithromycin 500 mg tablets (Merck S.A Industrias Quimicas, Sao Paulo, SP, Brazil, used as test formulation) and Klaricid (Abbott Laboratórios do Brasil Ltda, Sao Paulo, SP, Brazil, used as reference formulation) in 24 healthy volunteers.

MATERIAL AND METHODS

The study was conducted using an open, randomized, two-period crossover design with one-week interval between doses. Blood samples were collected at pre-dose, 0.33, 0.66, 1, 1.33, 1.66, 2, 2.5, 3, 4, 6, 8, 10, 12, 16, 20 and 24 hours after the administration. AUC was calculated by the trapezoidal rule extrapolation method. Cmax and tmax were compiled from the plasmatic concentration-time data. Analysis of variance was carried out using logarithmically transformed AUC(0-inf), AUC(0-24 h), Cmax and untransformed tmax.

RESULTS

Intraindividual coefficient of variation (CV%) values were 14.25% and 12.62%, respectively for Cmax and AUC(0-24 h). The geometric mean values (+/- SD) for AUC(0-24 h) (microg x h/ml), AUC(0-inf) (microg x h/ml), and Cmax (microg/ml) for test medication were 18.56 (+/- 6.87), 18.8 (+/- 5.70) and 2.45 (+/- 0.88); the obtained values for reference medication were 18.29 (+/- 5.39), 19.10 (+/- 7.21) and 2.5 (+/- 0.69). 90% Cl for clarithromycin geometric mean of AUC(0-24 h), AUC(0-inf) and Cmax ratios (test/reference) were: 93.6-105.9%, 93.8-106.2% and 89- 103.2%. CCONCLUSION The test medication was considered bioequivalent to the reference medication based on the rate and extent of absorption.

Antimicrobial activity of garlic, tea tree oil, and chlorhexidine against oral microorganisms

OBJECTIVE

To compare the antimicrobial activity of tea tree oil, garlic, and chlorhexidine solutions against oral microorganisms.

METHOD

The five-week study consisted of thirty subjects. The first week was considered baseline. All subjects used a control solution (second week), and were randomly divided into the three groups (third week): G1-0.12% chlorhexidine; G2 - 2.5% garlic (Allium sativum, L.); and G3 - 0.2% tea tree oil (Melaleuca alternifolia). Dishes containing blood agar and Mitis Salivarius Bacitracin agar (MSB) were inoculated with the subjects' saliva (collected twice a week). Total microorganisms and mutans streptococci were counted in blood agar and MSB, respectively.

RESULTS

Chlorhexidine and garlic groups showed antimicrobial activity against mutans streptococci, but not against other oral microorganisms. The tea tree oil group showed antimicrobial activity against mutans streptococci and other oral microorganisms. Maintenance of reduced levels of microorganisms was observed only for garlic and tea tree oil during the two consecutive weeks (fourth and fifth). Unpleasant taste (chlorhexidine 40%, tea tree oil 30%, garlic 100%), burning sensation (chlorhexidine 40%, tea tree oil 60%, garlic 100%), bad breath (chlorhexidine 40%, tea tree oil 20%, garlic 90%), and nausea (chlorhexidine 0%, tea tree oil 10%, garlic 30%) were reported.

CONCLUSION

Garlic and tea tree oil might be an alternative to chlorhexidine.

[Jaccoud's syndrome. A case report]

The study concerns a 44 year-old male patient with a history of intermittent episodes of rheumatic activity; the physical examination showed mitral valve stenosis and metacarpophalangeal joint deformities. The joint deformities were bilateral and symmetrical, similar to that of rheumatoid arthritis. Nevertheless, the ulnar deviation of the hands was reversible and there were no typical signs of rheumatoid arthritis in the X-ray. In view of the facts, the diagnosis of Jaccoud's Artrhopathy (JA) was made. The pathogenesis, the clinical features and the association between mitral valve stenosis and joints deformities of JA are discussed. This disease has a good prognosis and it is sparsely mentioned in the cardiologic literature. Many patients with JA are diagnosed as having rheumatoid arthritis, which is a chronic and disabling disease.