Rehabilitation therapy using the HUBER platform in chronic non-specific low back pain: a randomized controlled trial.

BACKGROUND: Non-specific chronic low back pain (NSCLBP) refers to a complex condition that involves structural, biomechanical, cognitive, psychological, social, and lifestyle issues. First-line therapies include physical therapy and exercise, as well as psychological follow-up and pain medication. AIM: The aim of this study was to assess the impact of a 6-week center-based program using a multi-axis motorized platform (HUBER) connected with force sensors, that allows the patients to execute isometric exercises on the spine flexion-to-extension ratio at 60 and 120°/s, pain, trunk flexibility, and disability. DESIGN: The design of the study was prospective, active control, parallel-group, assessor-blinded, randomized controlled trial. SETTING: The setting was outpatients physical therapy clinic. POPULATION: The population analyzed presented NSCLBP. METHODS: Seventy individuals with NSCLBP were randomized into 2 intervention arms (1:1 ratio): 1/standard rehabilitation group (STAND) with physiotherapy, balneotherapy and cycloergometer exercises and 2/HUBER rehabilitation group (HUB) with physiotherapy, balneotherapy and HUBER exercises. Both programs lasted 6 weeks, with 4 sessions of 2 hours each per week. RESULTS: Each group reported statistically significant improvements on the isokinetic spine strength, flexibility of the trunk, lumbar joint mobility, muscular endurance of the trunk and of the lower limbs, pain score and disability (P<0.05). The spine flexion/extension ratio at 60˚/s improved similarly between groups (-22.23 for HUB, and -13.04 for STAND; P=0.178) with a greater effect size in HUB. Only HUB reported a significant improvement in the spine flexion-to-extension ratio at 120˚/s (from 87.3 to 78.6, P=0.012). HUB reported a greater decrease in the Oswestry Disability Index (-16.83) compared to STAND (-12.11), with a statistically significant effect between groups (P=0.036). CONCLUSIONS: Exercises performed on the HUBER platform added to physiotherapy and balneotherapy are as effective as a standard rehabilitation program with physiotherapy, balneotherapy and cycloergometer exercises to improve isokinetic spine strength, lumbar joint mobility, flexibility and muscular endurance of the trunk and the lower limbs. In addition, exercising with the HUBER platform result in a greater reduction in disability compared to a standard rehabilitation program (clinicalTrials.gov: NCT05437016). CLINICAL REHABILITATION IMPACT: A variety of intervention techniques, including supervised exercise and manual therapy are now used to manage persistent NSCLBP. The added value of the HUBER device on disability suggests that the platform could be beneficial.

High-intensity interval exercise in chronic heart failure: protocol optimization.

BACKGROUND: There are little data on the optimization of high-intensity aerobic interval exercise (HIIE) protocols in patients with chronic heart failure (CHF). Therefore, we compared acute cardiopulmonary responses to 4 different HIIE protocols to identify the optimal one. METHODS AND RESULTS: Twenty men with stable systolic CHF performed 4 different randomly ordered single HIIE sessions with measurement of gas exchange. For all protocols (A, B, C, and D) exercise intensity was set at 100% of peak power output (PPO). Interval duration was 30 seconds (A and B) or 90 seconds (C and D), and recovery was passive (A and C) or active (50% of PPO in B and D). Time spent above 85% of VO(2peak) and time above the ventilatory threshold were similar across all 4 HIIE protocols. Total exercise time was significantly longer in protocols with passive recovery intervals (A: 1,651 ± 347 s; C: 1,574 ± 382 s) compared with protocols with active recovery intervals (B: 986 ± 542 s; D: 961 ± 556 s). All protocols appeared to be safe, with exercise tolerance being superior during protocol A. CONCLUSION: Among the 4 HIIE protocols tested, protocol A with short intervals and passive recovery appeared to be superior.

Telephone support oriented by accelerometric measurements enhances adherence to physical activity recommendations in noncompliant patients after a cardiac rehabilitation program.

OBJECTIVE: To assess the efficacy of a strategy, based on telephone support oriented by accelerometer measurements, on the adherence to physical activity (PA) recommendations in cardiac patients not achieving PA recommendations. DESIGN: Prospective and randomized study. SETTING: A cardiac rehabilitation program (CRP) at a clinic. PARTICIPANTS: Stable, noncompliant cardiac (coronary artery disease, heart failure, post-cardiovascular surgery) patients (weekly moderate-intensity PA <150 min) were randomly assigned to an intervention group (n=19) or a control group (n=10). INTERVENTIONS: The intervention group wore an accelerometer for 8 weeks. Every 15 days, feedback and support were provided by telephone. The control group wore the accelerometer during the 8th week of the intervention only. MAIN OUTCOME MEASURES: Active energy expenditure (EE) (in kilocalories) and the time spent doing light, moderate, or intense PA (minutes per week). RESULTS: In the intervention group, the time spent at moderate-intensity PA increased from 95.6±80.7 to 137.2±87.5 min/wk between the 1st and 8th week (P=.002), with 36.8% of the sample achieving the target amount of moderate-intensity PA. During the 8th week, the EE averaged 543.7±144.1 kcal and 266.7±107.4 kcal in the intervention group and control group, respectively (P=.004). CONCLUSIONS: Telephone support based on accelerometer recordings appeared to be an effective strategy to improve adherence to PA in noncompliant patients. This intervention could be implemented after a CRP as an inexpensive, modern, and easy-to-use strategy.

Effects of an Intensive 6-Week Rehabilitation Program with the HUBER Platform in the Treatment of Non-Specific Chronic Low Back Pain: A Pilot Study.

Non-specific chronic low back pain (NSCLBP) is defined as a complex disorder involving structural, biomechanical, cognitive, psychological, social, and lifestyle factors. Non-pharmacological approaches such as exercise and physical therapy have been proposed in first-line treatments, along with psychological follow-up and pain medication if needed. Our objective was to evaluate the effectiveness of an intensive rehabilitation program with HUBER (a multi-axis motorized platform equipped with force sensors, allowing patients to perform physical exercises in an isometric mode) on the spine flexion-to-extension ratio at 60 and 120°/s, pain, and trunk flexibility in individuals with NSCLBP. Twelve participants underwent a clinical evaluation including isokinetic spine strength and participated in a 6-week rehabilitation program with HUBER 360 Evolution. The main findings of this pilot study show that the flexor/extensor ratios at 60°, the flexibility of the hamstring and quadriceps, and muscular endurance of the trunk, disability, and quality of life were significantly improved at the end of the rehabilitation program (p < 0.05). Low back pain and analgesic medication were also reduced. Exercising with the HUBER Platform seems to be effective in managing NSCLBP but a randomized study with a larger sample size and a control group is necessary.

Comparison of gas exchange data using the Aquatrainer system and the facemask with Cosmed K4b2 during exercise in healthy subjects.

The aim of this study was to determine the level of agreement between the new Aquatrainer system and the facemask in the assessment of submaximal and maximal cardiopulmonary responses during exercise performed on ergocycle. Twenty-six physically active healthy subjects (mean age: 41 +/- 14 years) performed a submaximal constant work test followed by maximal incremental exercise test on ergocycle, one with cardiopulmonary responses measured using the Cosmed K4b2 facemask, the other using the Cosmed K4b2 Aquatrainer. Using the Aquatrainer, the gas exchange variables at 100 W were significantly lower for VO(2) (1,483 +/- 203 vs. 1,876 +/- 204 ml min(-1), P < 0.0001), VCO(2) (1,442 +/- 263 vs. 1,749 +/- 231 ml min(-1), P < 0.0001), VE (38 +/- 5 vs. 44 +/- 6 l min(-1), P < 0.0001), and VT (1.92 +/- 0.47 vs. 2.18 +/- 0.41 l, P < 0.0001) relative to facemask. The bias +/-95% limits of agreement (LOA) for VO(2) was 393 +/- 507 ml min(-1) for the submaximal constant work test at 100 W and 495 +/- 727 ml min(-1) for VO(2max). At maximal intensity, cardiopulmonary responses measured with the Aquatrainer system were significantly lower for: VO(2) (2,799 +/- 751 vs. 3,294 +/- 821 ml min(-1), P < 0.0001), VCO(2) (3,426 +/- 836 vs. 3,641 +/- 946 ml min(-1), P = 0.012), VE (98 +/- 21 vs. 108 +/- 26 l min(-1), P = 0.0009) relative to facemask. A non-constant measurement error [interaction effect: (facemask or aquatrainer) x power] was noted from 60 to 270 W for VO(2) (ml min(-1)), VCO(2) (ml min(-1)), ventilation (l min(-1)) (P < 0.0001) and VT (l, P = 0.0001). Additional studies are required to detect the main sources of error that could be physical and/or physiological in nature. Due to the significant measurement error, the new Aquatrainer system should be used with extreme caution in filed testing conditions of swimmers.

Optimization of high intensity interval exercise in coronary heart disease.

High intensity interval training has been shown to be more effective than moderate intensity continuous training for improving maximal oxygen uptake (VO(2max)) in patients with coronary heart disease (CHD). However, no evidence supports the prescription of one specific protocol of high intensity interval exercise (HIIE) in this population. The purpose of this study was to compare the acute cardiopulmonary responses with four different single bouts of HIIE in order to identify the most optimal one in CHD patients. Nineteen stable CHD patients (17 males, 2 females, 65 +/- 8 years) performed four different bouts of HIIE, all with exercise phases at 100% of maximal aerobic power (MAP), but which varied in interval duration (15 s for mode A and B and 60 s for mode C and D) and type of recovery (0% of MAP for modes A and C and 50% of MAP for modes B and D). A passive recovery phase resulted in a longer time to exhaustion compared to an active recovery phase, irrespective of the duration of the exercise and recovery periods (15 or 60 s, p < 0.05). Time to exhaustion also tended to be higher with mode A relative to mode C (p = 0.06). Despite differences in time to exhaustion between modes, time spent at a high percentage of VO(2max) was similar between HIIE modes except for less time spent above 90 and 95% of VO(2max) for mode C when compared with modes B and D. When considering perceived exertion, patient comfort and time spent above 80% of VO(2max), mode A appeared to be the optimal HIIE session for these coronary patients.

Short-term effects of a 3-week interval training program on heart rate variability in chronic heart failure. A randomised controlled trial.

BACKGROUND: Exaggerated sympathetic nervous system activity associated with low heart rate variability (HRV) is considered to trigger cardiac arrhythmias and sudden death. Regular exercise training is efficient to improve autonomic balance. OBJECTIVE: We aimed to verify the superiority of high-intensity interval training (HIIT) to enhance HRV, cardiorespiratory fitness and cardiac function as compared with moderate intensity continuous training (MICT) in a short, intense cardiac rehabilitation program. METHODS: This was a prospective, monocentric, evaluator-blinded, randomised (1:1) study with a parallel two-group design. Overall, 31 individuals with voluntary chronic heart failure (CHF) (left ventricular ejection fraction [LVEF]<45%) were allocated to MICT (n=15) or HIIT (n=16) for a short rehabilitation program (mean [SD] 27 [4] days). Participants underwent 24-hr electrocardiography, echocardiography and a cardiopulmonary exercise test at entry and at the end of the study. RESULTS: High-frequency power in normalized units (HFnu%) measured as HRV increased with HIIT (from 21.2% to 26.4%, P<0.001) but remained unchanged with MICT (from 23.1% to 21.9%, P=0.444, with a significant intergroup difference, P=0.003). Resting heart rate (24-hr Holter electrocardiography) decreased significantly for both groups (from 68.2 to 64.6 bpm and 66.0 to 63.5 bpm for MICT and HIIT, respectively, with no intergroup difference, P=0.578). The 2 groups did not differ in premature ventricular contractions. Improvement in peak oxygen uptake was greater with HIIT than MICT (+21% vs. +5%, P=0.009). LVEF improved with only HIIT (from 36.2% to 39.5%, P=0.034). CONCLUSIONS: In this short rehabilitation program, HIIT was significantly superior to the classical MICT program for enhancing parasympathetic tone and peak oxygen uptake. CLINICALTRIALS. GOV IDENTIFIER: NCT03603743.

Vitamin D deficiency related to physical capacity during cardiac rehabilitation.

BACKGROUND: Vitamin D deficiency is a frequent pathology associated with cardiovascular diseases and physical performance. OBJECTIVE: To study the link between 25-hydroxyvitamin D (25OHD) level and physical performance and gain in physical performance after cardiovascular rehabilitation (CVR) with vitamin D deficiency. METHODS: 25OHD level was assessed in a retrospective cohort of patients admitted for CVR. Data were collected on physical fitness [6-min walk test distance (6MWD) in percentage of predicted, maximal power (Pmax)]. The threshold of vitamin D deficiency was 20ng/ml chosen according to the literature. RESULTS: Among the 131 patients included, as compared with those with nondeficiency (n=83; 63%), patients with vitamin D deficiency (n=48, 37%) had lower initial 6MWD (82±18 vs 89±12% predicted, P=0.009) and Pmax (100±58 vs 120±39W, P=0.006). After CVR, this difference was maintained. The improvement in 6MWD and Pmax was significantly lower with deficiency than nondeficiency, for an increase of 11±8% versus 14±9% predicted (P=0.048) and 10±30 versus 32±30W (P=0.00001), respectively. CONCLUSION: Vitamin D deficiency may be associated with impaired physical fitness before CVR and a smaller gain in physical fitness with CVR, probably related to the action of vitamin D on the muscle.

The efficacy of transcutaneous electrical nerve stimulation on the improvement of walking distance in patients with peripheral arterial disease with intermittent claudication: study protocol for a randomised controlled trial: the TENS-PAD study.

BACKGROUND: In patients with peripheral arterial disease (PAD), walking improvements are often limited by early pain onset due to vascular claudication. It would thus appear interesting to develop noninvasive therapeutic strategies, such as transcutaneous electrical nerve stimulation (TENS), to improve the participation of PAD patients in rehabilitation programmes, and thus improve their quality of life. Our team recently tested the efficacy of a single 45-min session of 10-Hz TENS prior to walking. TENS significantly delayed pain onset and increased the pain-free walking distance in patients with class-II PAD. We now seek to assess the efficacy of a chronic intervention that includes the daily use of TENS for 3 weeks (5 days a week) on walking distance in Leriche-Fontaine stage-II PAD patients. METHODS/DESIGN: This is a prospective, double-blind, multicentre, randomised, placebo-controlled trial. One hundred subjects with unilateral PAD (Leriche-Fontaine stage II) will be randomised into two groups (1:1). For the experimental group (TENS group): the treatment will consist of stimulation of the affected leg (at a biphasic frequency of 10 Hz, with a pulse width of 200 µs, maximal intensity below the motor threshold) for 45 min per day, in the morning before the exercise rehabilitation programme, for 3 weeks, 5 days per week. For the control group (SHAM group): the placebo stimulation will be delivered according to the same modalities as for the TENS group but with a voltage level automatically falling to zero after 10 s of stimulation. First outcome: walking distance without pain. SECONDARY OUTCOMES: transcutaneous oxygen pressure (TcPO2) measured during a Strandness exercise test, peak oxygen uptake (VO2 peak), endothelial function (EndoPAT®), Ankle-brachial Pressure Index, Body Mass Index, lipid profile (LDL-C, HDL-C, triglycerides), fasting glycaemia, HbA1c level, and the WELCH questionnaire. DISCUSSION: TENS-PAD is the first randomised controlled trial that uses transcutaneous electrical therapy as an adjuvant technique to improve vascular function in the treatment of PAD. If the results are confirmed, this technique could be incorporated into the routine care in cardiovascular rehabilitation centers and used in the long term by patients to improve their walking capacity. TRIAL REGISTRATION: ClinicalTrials.gov, ID: NCT02678403 . Registered on 9 February 2016. SPONSOR: Toulouse University Hospital.

Exercise training-induced modification in autonomic nervous system: An update for cardiac patients.

Patients with cardiovascular disease show autonomic dysfunction, including sympathetic activation and vagal withdrawal, which leads to fatal events. This review aims to place sympathovagal balance as an essential element to be considered in management for cardiovascular disease patients who benefit from a cardiac rehabilitation program. Many studies showed that exercise training, as non-pharmacologic treatment, plays an important role in enhancing sympathovagal balance and could normalize levels of markers of sympathetic flow measured by microneurography, heart rate variability or plasma catecholamine levels. This alteration positively affects prognosis with cardiovascular disease. In general, cardiac rehabilitation programs include moderate-intensity and continuous aerobic exercise. Other forms of activities such as high-intensity interval training, breathing exercises, relaxation and transcutaneous electrical stimulation can improve sympathovagal balance and should be implemented in cardiac rehabilitation programs. Currently, the exercise training programs in cardiac rehabilitation are individualized to optimize health outcomes. The sports science concept of the heart rate variability (HRV)-vagal index used to manage exercise sessions (for a goal of performance) could be implemented in cardiac rehabilitation to improve cardiovascular fitness and autonomic nervous system function.

Whole-body strength training with Huber Motion Lab and traditional strength training in cardiac rehabilitation: A randomized controlled study.

BACKGROUND: Isometric strengthening has been rarely studied in patients with coronary heart disease (CHD), mainly because of possible potential side effects and lack of appropriate and reliable devices. OBJECTIVE: We aimed to compare 2 different modes of resistance training, an isometric mode with the Huber Motion Lab (HML) and traditional strength training (TST), in CHD patients undergoing a cardiac rehabilitation program. DESIGN: We randomly assigned 50 patients to HML or TST. Patients underwent complete blinded evaluation before and after the rehabilitation program, including testing for cardiopulmonary exercise, maximal isometric voluntary contraction, endothelial function and body composition. RESULTS: After 4 weeks of training (16 sessions), the groups did not differ in body composition, anthropometric characteristics, or endothelial function. With HML, peak power output (P=0.035), maximal heart rate (P<0.01) and gain of force measured in the chest press position (P<0.02) were greater after versus before training. CONCLUSION: Both protocols appeared to be well tolerated, safe and feasible for these CHD patients. A training protocol involving 6s phases of isometric contractions with 10s of passive recovery on an HML device could be safely implemented in rehabilitation programs for patients with CHD and improve functional outcomes.

Reliability and concurrent validity of the Acti'MET calculator: A new tool to assess physical activity in cardiac rehabilitation.

OBJECTIVE: We created a tool for assessing physical activity (PA), the Acti'MET calculator, to quickly estimate weekly energy expenditure. This study aimed to assess the metrological properties of the tool in cardiac rehabilitation (CR). METHODS: Two examiners evaluated the reliability and concurrent validity of the tool with cardiac patients. The validity of the tool was assessed by comparison with other classical methods for measurement of PA such as the Dijon Physical Activity Score (PAS) and the International Physical Activity Questionnaire (IPAQ) score, the 6-min walk test (6MWT) and the cardiopulmonary maximal exercise test. Correlation was assessed by Pearson or Spearman correlation analysis. RESULTS: For the 36 cardiac patients (mean age 55±11 years, 24 men), inter-rater and intra-rater reliabilities were strong: r=0.87 and r=0.98, respectively, both P<0.0001. We found a strong correlation of the Acti'MET score with the IPAQ score (r=0.88, P<0.0001), moderate correlation with the PAS (r=0.39, P<0.05) and 6MWT (r=0.54, P<0.01), and no correlation with peak power output. CONCLUSION: The Acti'MET calculator is reliable, valid and easy to use for assessing PA in CR. This tool seems to well reflect the weekly PA, unlike the PAS, which evaluates PA on a yearly basis.

Whole-body strength training using a Huber Motion Lab in coronary heart disease patients: safety, tolerance, fuel selection, and energy expenditure aspects and optimization.

OBJECTIVE: The aim of this study was to investigate safety, tolerance, relative exercise intensity, and muscle substrate oxidation during sessions performed on a Huber Motion Lab in coronary heart disease patients. DESIGN: After an assessment of Vo2 peak, 20 coronary heart disease patients participated in two different exercises performed in random order at 40% and 70% (W40 and W70) of the maximal isometric voluntary contraction. RESULTS: No significant arrhythmia or abnormal blood pressure responses occurred during either session, and no muscle soreness was reported within 48 hrs posttest. The authors found a difference between W40 and W70 sessions for mean (standard deviation) ventilation (25.1% [8%] and 32.1% [9%] of maximal ventilation, respectively; P = 0.04) and a small difference for mean (standard deviation) heart rate (73 [7] and 79 [8] beats/min, respectively; P < 0.01). When compared with the W40, the W70 was associated with higher active energy expenditure (2.4 [0.6] and 3.1 [0.9] Kcal/min, respectively; P < 0.0001) and a similar mean (standard deviation) oxygen uptake (5.5 [1] and 6.6 [1] ml/min per kilogram, respectively; P = 0.07). The qualitative percentages of carbohydrates and lipids oxidized were 71% and 29%, respectively, at W40 and 91% and 9%, respectively, at W70. CONCLUSIONS: Both protocols, which consisted of repeating 6-sec phases of contractions with 10 secs of passive recovery on the Huber Motion Lab, seemed to be well tolerated, safe, and feasible in this group of coronary heart disease patients.

Acute High-Intensity Intermittent Aerobic Exercise Reduces Plasma Angiopoietin-Like 2 in Patients With Coronary Artery Disease.

BACKGROUND: Circulating levels of angiopoietin-like 2 (ANGPTL2), a proinflammatory and proatherogenic protein, are elevated in patients with coronary artery disease (CAD). We hypothesized that high-intensity intermittent exercise (HIIE), known to be beneficial in patients with CAD, would reduce circulating ANGPTL2 levels. METHODS: Plasma levels of ANGPTL2 were measured before and 20 minutes, 24 hours, and 72 hours after an acute exercise session in a crossover study comparing HIIE to moderate-intensity continuous exercise (MICE) in 14 patients with CAD and 20 age-matched and 20 young healthy controls. RESULTS: Pre-exercise ANGPTL2 levels were 3-fold higher in patients with CAD than in age-matched controls (P < 0.05) and correlated negatively with Vo2max/lean body mass (P < 0.0001). In healthy controls, ANGPTL2 levels were low and not affected by HIIE or MICE. In patients with CAD, ANGPTL2 levels decreased significantly by 41% after 20 minutes of HIIE, a reduction that was maintained after 24 and 72 hours (P < 0.05). In contrast, although ANGPTL2 levels decreased by 47% after 20 minutes of MICE, they increased by 104% after 24 hours and returned to baseline values after 72 hours (P < 0.05). A negative correlation was observed between this increase in ANGPTL2 levels and the mean rate-pressure product (heart rate × systolic blood pressure; index of myocardial O2 consumption) measured during MICE, suggesting that subclinical ischemia might promote ANGPTL2 expression. CONCLUSIONS: In patients with CAD, circulating ANGPTL2 levels are acutely reduced after HIIE and transiently increased after MICE. A sustained reduction in circulating ANGPTL2 levels could contribute to the chronic beneficial cardiometabolic effects of HIIE in patients with CAD.

Improved Walking Claudication Distance with Transcutaneous Electrical Nerve Stimulation: An Old Treatment with a New Indication in Patients with Peripheral Artery Disease.

OBJECTIVE: The aim of this study was to determine whether 45 mins of transcutaneous electrical nerve stimulation before exercise could delay pain onset and increase walking distance in peripheral artery disease patients. DESIGN: After a baseline assessment of the walking velocity that led to pain after 300 m, 15 peripheral artery disease patients underwent four exercise sessions in a random order. The patients had a 45-min transcutaneous electrical nerve stimulation session with different experimental conditions: 80 Hz, 10 Hz, sham (presence of electrodes without stimulation), or control with no electrodes, immediately followed by five walking bouts on a treadmill until pain occurred. The patients were allowed to rest for 10 mins between each bout and had no feedback concerning the walking distance achieved. RESULTS: Total walking distance was significantly different between T10, T80, sham, and control (P < 0.0003). No difference was observed between T10 and T80, but T10 was different from sham and control. Sham, T10, and T80 were all different from control (P < 0.001). There was no difference between each condition for heart rate and blood pressure. CONCLUSIONS: Transcutaneous electrical nerve stimulation immediately before walking can delay pain onset and increase walking distance in patients with class II peripheral artery disease, with transcutaneous electrical nerve stimulation of 10 Hz being the most effective.

Direct evidences for sympathetic hyperactivity and baroreflex impairment in Tako Tsubo cardiopathy.

BACKGROUND: The exact pathophysiology of Tako-Tsubo cardiomyopathy (TTC) remains unknown but a role for sympathetic hyperactivity has been suggested. Up to now, no direct evidence of sympathetic nerve hyperactivity has been established nor involvement of sympathetic baroreflex identified. The aim of our study was to determine, by direct sympathetic nerve activity (SNS) recording if sympathetic nervous system activity is increased and spontaneous baroreflex control of sympathetic activity reduced in patients with TTC. METHODS: We included 13 patients who presented with TTC and compared their SNS activity and spontaneous baroreflex control of sympathetic activity with that of 13 control patients with acutely decompensated chronic heart failure. SNS activity was evaluated by microneurography, a technique assessing muscle sympathetic nerve activity (MSNA). Spontaneous baroreflex control of sympathetic activity was evaluated as the absolute value of the slope of the regression line representing the relationship between spontaneous diastolic blood pressure values and concomitant SNS activity. Control patients were matched for age, sex, left ventricular ejection fraction and creatinine clearance. RESULTS: The mean age of the patients with TTC was 80 years, all patients were women. There were no significant differences between the two groups of patients for blood pressure, heart rate or oxygen saturation level. TTC patients presented a significant increase in sympathetic nerve activity (MSNA median 63.3 bursts/min [interquartile range 61.3 to 66.0] vs median 55.7 bursts/min [interquartile range 51.0 to 61.7]; p = 0.0089) and a decrease in spontaneous baroreflex control of sympathetic activity compared to matched control patients (spontaneous baroreflex control of sympathetic activity median 0.7%burst/mmHg [interquartile range 0.4 to 1.9] vs median 2.4%burst/mmHg [interquartile range 1.8 to 2.9]; p = 0.005). CONCLUSIONS: We report for the first time, through direct measurement of sympathetic nerve activity, that patients with TTC exhibit elevated SNS activity associated with a decrease in spontaneous baroreflex control of sympathetic activity. These data may explain the pathophysiology and clinical presentation of patient with TTC.

Acute electromyostimulation decreases muscle sympathetic nerve activity in patients with advanced chronic heart failure (EMSICA Study).

BACKGROUND: Muscle passive contraction of lower limb by neuromuscular electrostimulation (NMES) is frequently used in chronic heart failure (CHF) patients but no data are available concerning its action on sympathetic activity. However, Transcutaneous Electrical Nerve Stimulation (TENS) is able to improve baroreflex in CHF. The primary aim of the present study was to investigate the acute effect of TENS and NMES compared to Sham stimulation on sympathetic overactivity as assessed by Muscle Sympathetic Nerve Activity (MSNA). METHODS: We performed a serie of two parallel, randomized, double blinded and sham controlled protocols in twenty-two CHF patients in New York Heart Association (NYHA) Class III. Half of them performed stimulation by TENS, and the others tested NMES. RESULTS: Compare to Sham stimulation, both TENS and NMES are able to reduce MSNA (63.5 ± 3.5 vs 69.7 ± 3.1 bursts / min, p < 0.01 after TENS and 51.6 ± 3.3 vs 56.7 ± 3.3 bursts / min, p < 0, 01 after NMES). No variation of blood pressure, heart rate or respiratory parameters was observed after stimulation. CONCLUSION: The results suggest that sensory stimulation of lower limbs by electrical device, either TENS or NMES, could inhibit sympathetic outflow directed to legs in CHF patients. These properties could benefits CHF patients and pave the way for a new non-pharmacological approach of CHF.

Acute responses to intermittent and continuous exercise in heart failure patients.

BACKGROUND: The purpose of this study was to compare cardiopulmonary responses, exercise adherence, tolerance, and safety of optimized high-intensity interval exercise (HIIE) compared with moderate-intensity continuous exercise (MICE) in patients with heart failure and reduced ejection fraction (HFREF). METHODS: Twenty patients with HFREF (aged 61 ± 9.9 years) were randomly assigned to HIIE corresponding to 2 × 8 minutes of 30-second intervals at 100% of peak power output and 30-second passive recovery intervals and to a 22-minute MICE corresponding to 60% of peak power output. Gas exchange, electrocardiogram, and blood pressure were measured continuously. Cardiac troponin T (cTnT), C-reactive protein (CRP), and brain natriuretic peptide (BNP) were measured before, 20 minutes after, and 24 hours after HIIE and MICE. RESULTS: Cardiopulmonary responses did not differ between MICE and HIIE. Higher exercise adherence and efficiency were observed on HIIE with a similar perceived exertion and time spent above 90% of peak oxygen consumption compared with MICE. Neither HIIE nor MICE caused any significant arrhythmias or increased CRP, BNP, or cTnT. CONCLUSIONS: Compared with MICE, HIIE demonstrated a higher exercise adherence and was well tolerated in patients with HFREF, while still providing a high-level physiological stimulus and leaving indices of inflammation (CRP), myocardial dysfunction (BNP), and myocardial necrosis (cTnT) unaffected.

A single bout of high-intensity interval exercise does not increase endothelial or platelet microparticles in stable, physically fit men with coronary heart disease.

BACKGROUND: High-intensity interval exercise (HIIE) is gaining in popularity in fitness centres, even among coronary heart disease (CHD) patients. However, whether HIIE can have deleterious acute effects on the vasculature in CHD has not been studied. We hypothesized that when compared with moderate-intensity continuous exercise (MICE), a single bout of HIIE could lead to vascular damage and increasing numbers of circulating endothelial and platelet microparticles (EMPs, PMPs) in stable, physically fit CHD patients. METHODS: Nineteen male CHD patients (aged 62 ± 11 years) underwent, in random order, a single session of HIIE corresponding to 15-second intervals at 100% of peak power output and 15-second passive recovery intervals, and an isocaloric MICE session. EMPs (CD31+ and/or CD62E+ and CD42b-); PMPs (CD42b+); nitrates and nitrites; prostacycline; and troponin T, cardiac form (cTnT), were measured 10 minutes before exercise and 20 minutes, 24 hours, and 72 hours after both exercise sessions. RESULTS: EMPs, PMPs, nitrates and nitrites, prostacycline, and cTnT remained unchanged after both HIIE and MICE exercise sessions. Initial EMP concentration correlated inversely with EMP concentration 20 minutes post exercise, irrespective of exercise modality (r = 0.78, P < 0.0001). CONCLUSIONS: A single HIIE session with very short exercise and passive recovery periods appears safe and does not induce changes to markers of endothelial function. Future studies are required to determine the safety of a long-term HIIE training program.