Exercise Tolerance

Isosorbide, a nitrate-class vasodilator, remains an essential pharmacological agent in the management of ischemic heart disease, particularly angina pectoris and heart failure with reduced ejection fraction. Acting primarily through the nitric oxide-cyclic guanosine monophosphate (NO-cGMP) pathway, it produces systemic and coronary vasodilation that decreases myocardial oxygen demand and enhances perfusion to ischemic regions. This review discusses the pharmacological properties of isosorbideincluding its mechanism of action, pharmacokinetics, and hemodynamic effects-alongside its approved and off-label clinical indications. Particular attention is given to contraindications, adverse reactions, the development of nitrate tolerance, and strategies for safe administration. Furthermore, the review underscores the importance of interprofessional collaboration in optimizing therapeutic outcomes, emphasizing the role of clinicians, nurses, pharmacists, and patient educators in ensuring adherence, minimizing risk, and improving overall cardiovascular care.

Background: Physiological markers such as maximal oxygen uptake (VO2 Max), lactate threshold (LT), and peak blood lactate (PBL) are critical for understanding the aerobic and anaerobic adaptations that influence athletic performance. However, their combined assessment across different sporting disciplines is limited.
Objectives: This study aimed to compare VO2 Max, LT, and PBL between power and endurance athletes and to explore their interrelationships among these variables within each group.
Methods: A cross-sectional comparative design was employed involving 60 athletes aged 18-21 years (30 power athletes and 30 endurance athletes) with a minimum of three years of competitive experience. VO2 Max was measured via graded exercise testing, Lactate Threshold through serial capillary blood sampling, and Peak Blood Lactate with three minutes post-exercise. Independent t-tests and Pearson’s correlation coefficient were used for data analysis (p < 0.05).
Results: Endurance athletes exhibited significantly higher VO2 Max and LT values, reflecting superior aerobic capacity and delayed lactate accumulation, whereas power athletes showed significantly greater PBL, indicating enhanced anaerobic glycolysis and metabolic acidosis tolerance. Strong positive correlations were found between VO2 Max and LT in both groups, where LT and PBL were not significantly correlated.
Conclusion: Distinct metabolic profiles characterize power and endurance athletes, underscoring the importance of sport-specific training interventions and comprehensive physiological assessments to optimize performance and conditioning strategies.

The beneficial effect of exercise training and exercise-based cardiac rehabilitation on symptom-free exercise capacity,cardiovascular and skeletal muscle function, quality of life, general healthy lifestyle, and reduction of depressive symptoms and psychosocial stress is nowadays well recognized. However, it remains largely obscure, which characteristics of physical activity (PA) and exercise training--frequency, intensity, time (duration), type (mode), and volume (dose: intensity x duration) of exercise--are the most effective. The present paper, therefore, will deal with these exercise characteristics in the management of individuals with cardiovascular disease, i.e. coronary artery disease and chronic heart failure patients, but also in patients with congenital or valvular heart disease. Based on the current literature, and if sufficient evidence is available, recommendations from the European Association on Cardiovascular Prevention and Rehabilitation are formulated regarding fr...

Little is known about survival and clinical prognostic factors in females with chronic obstructive pulmonary disease (COPD). The aim of the present study was to determine the survival difference between males and females with COPD and to compare the value of the different prognostic factors for the disease. In total, 265 females and 272 males with COPD matched at baseline by BODE (body mass index, airflow obstruction, dyspnoea, exercise capacity) and American Thoracic Society/European Respiratory Society/Global Initiative of Chronic Obstructive Lung Disease criteria were prospectively followed. Demographics, lung function, St George's Respiratory Questionnaire, BODE index, the components of the BODE index and comorbidity were determined. Survival was documented and sex differences were determined using Kaplan-Meier analysis. The strength of the association of the studied variables with mortality was determined using multivariate and receiver operating curves analysis. All-cause (40 versus 18%) and respiratory mortality (24 versus 10%) were higher in males than females. Multivariate analysis identified the BODE index in females and the BODE index and Charlson comorbidity score in males as the best predictors of mortality. The area under the curve of the BODE index was a better predictor of mortality than the forced expiratory volume in one second for both sexes. At similar chronic obstructive pulmonary disease severity by BODE index and forced expiratory volume in one second, females have significantly better survival than males. For both sexes the BODE index is a better predictor of survival than the forced expiratory volume in one second.

The objective of this study was to describe the renal and extrarenal findings in patients with recessively inherited familial hypomagnesemia with hypercalciuria and nephrocalcinosis (FHHNC) associated with CLDN19 mutations. Design, setting, participants, & measurements Medical records of three patients from two French unrelated families with CLDN19 mutations were retrospectively examined. Direct sequencing of CLDN19 identified a known variant (p.Gly20Asp) in all patients and a new missense mutation (p.Val44Met) in one (compound heterozygous). The patients' renal phenotype closely mimicked CLDN16-related nephropathy: low serum Mg 2ϩ (Ͻ0.65 mmol/L) despite oral supplementation, hypercalciuria partly thiazide-sensitive, and progressive renal decline with ESRD reached at age 16 and 22 years in two individuals. Primary characteristics (failure to thrive, recurrent urinary tract infections, or abdominal pain), age at onset (0.8 to 16 years), and rate of renal decline were highly heterogeneous. Ocular involvement was identified in all patients, although two patients did not have visual loss. Additionally, exercise intolerance with pain, weakness, and electromyographical alterations mimicking a Ca 2ϩ /K ϩ channelopathy (pattern V) were observed in two of three individuals. These features persisted despite the normalization of serum K ϩ and Mg 2ϩ after renal transplantation. Conclusions Ocular manifestations, even subtle, and exercise intolerance mimicking mild to moderate periodic paralysis are two symptoms that need to be searched for in patients with FHHNC and may indicate CLDN19 mutations.

Summary Background and objectives The objective of this study was to describe the renal and extrarenal findings in patients with recessively inherited familial hypomagnesemia with hypercalciuria and nephrocalcinosis (FHHNC) associated with CLDN19 mutations. Design, setting, participants, & measurements Medical records of three patients from two French unrelated families with CLDN19 mutations were retrospectively examined. Results Direct sequencing of CLDN19 identified a known variant (p.Gly20Asp) in all patients and a new missense mutation (p.Val44Met) in one (compound heterozygous). The patients&#39; renal phenotype closely mimicked CLDN16-related nephropathy: low serum Mg2+ (&lt;0.65 mmol/L) despite oral supplementation, hypercalciuria partly thiazide-sensitive, and progressive renal decline with ESRD reached at age 16 and 22 years in two individuals. Primary characteristics (failure to thrive, recurrent urinary tract infections, or abdominal pain), age at onset (0.8 to 16 years),...

BACKGROUND The clinical significance of exercise-induced chest pain remains controversial, as reflected by sharply discordant clinical results within the medical literature. Thus, we developed a prospective study to compare the functional significance of silent versus symptomatic ischemia and to evaluate whether patient selection biases influence this analysis. METHODS AND RESULTS We evaluated 117 patients (mean age, 63 +/- 9 years) with ischemic ST-segment depression during treadmill testing. Each patient underwent Tl-201 myocardial perfusion single-photon emission computed tomography (SPECT) after exercise followed by 24-ambulatory ECG monitoring. Patients were divided into silent versus symptomatic cohorts and were compared for the degree of hemodynamic, exercise and ambulatory ECG, and thallium abnormalities during stress testing. Analyses were repeated as the patient population became increasingly restricted. Compared with the silent patients, patients with chest pain during ex...

Introduction: Women with fibromyalgia (FM) have symptoms of increased muscular fatigue and reduced exercise tolerance, which may be associated with alterations in muscle microcirculation and oxygen metabolism. This study used near-infrared diffuse optical spectroscopies to noninvasively evaluate muscle blood flow, blood oxygenation and oxygen metabolism during leg fatiguing exercise and during arm arterial cuff occlusion in post-menopausal women with and without FM. Methods: Fourteen women with FM and twenty-three well-matched healthy controls participated in this study. For the fatiguing exercise protocol, the subject was instructed to perform 6 sets of 12 isometric contractions of knee extensor muscles with intensity steadily increasing from 20 to 70% maximal voluntary isometric contraction (MVIC). For the cuff occlusion protocol, forearm arterial blood flow was occluded via a tourniquet on the upper arm for 3 minutes. Leg or arm muscle hemodynamics, including relative blood flow (rBF), oxy-and deoxy-hemoglobin concentration ([HbO 2 ] and [Hb]), total hemoglobin concentration (THC) and blood oxygen saturation (StO 2 ), were continuously monitored throughout protocols using a custom-built hybrid diffuse optical instrument that combined a commercial near-infrared oximeter for tissue oxygenation measurements and a custom-designed diffuse correlation spectroscopy (DCS) flowmeter for tissue blood flow measurements. Relative oxygen extraction fraction (rOEF) and oxygen consumption rate (rVO 2 ) were calculated from the measured blood flow and oxygenation data. Post-manipulation (fatiguing exercise or cuff occlusion) recovery in muscle hemodynamics was characterized by the recovery half-time, a time interval from the end of manipulation to the time that tissue hemodynamics reached a half-maximal value. Results: Subjects with FM had similar hemodynamic and metabolic response/recovery patterns as healthy controls during exercise and during arterial occlusion. However, tissue rOEF during exercise in subjects with FM was significantly lower than in healthy controls, and the half-times of oxygenation recovery (Δ[HbO 2 ] and Δ[Hb]) were significantly longer following fatiguing exercise and cuff occlusion. Conclusions: Our results suggest an alteration of muscle oxygen utilization in the FM population. This study demonstrates the potential of using combined diffuse optical spectroscopies (i.e., NIRS/DCS) to comprehensively evaluate tissue oxygen and flow kinetics in skeletal muscle.

The recent development of treatment modalities for patients with idiopathic pulmonary arterial hypertension has been based on the evaluation of many different markers such as functional capacity, addressed by NYHA classification, six-minute walk test (6 MWT) and hemodynamic parameters. The aim of this study was to evaluate the correlation of N-terminal fragment (NT-proBNP) with other markers in IPAH and its potential for patient stratification. We studied 42 IPAH patients consecutively evaluated through right heart catheterization in the absence of any specific treatment for pulmonary hypertension. Blood samples, clinical evaluation and 6 MWF distance were collected at baseline. The levels of NT-proBNP showed a high correlation with hemodynamic parameters, such as pulmonary vascular resistance (r ¼ 0:80, Po0.001). A significant difference was found among patients with different functional classes, addressed by NYHA classification (Po 0.02 for all groups comparison). The discriminant analysis reinforced the ability of NT-proBNP to stratify patients according to NYHA functional class. Compared to the other variables studied (hemodynamics and 6 MWT), NT-proBNP had the lowest level of overlap in the stratification of IPAH patients. We conclude that NT-proBNP differs among the different functional classes and correlates with other measures of disease severity, although its role in predicting survival still needs to be addressed.

Background: Pulmonary arterial hypertension is a progressive disease that is characterized by dyspnea and exercise intolerance. Impairment in skeletal muscle has recently been described in PAH, although the degree to which this impairment is solely determined by the hemodynamic profile remains uncertain. The aim of this study was to verify the association of structural and functional skeletal muscle characteristics with maximum exercise in PAH. Methods: The exercise capacity, body composition, CT area of limb muscle, quality of life, quadriceps biopsy and hemodynamics of 16 PAH patients were compared with those of 10 controls. Results: PAH patients had a significantly poorer quality of life, reduced percentage of lean body mass, reduced respiratory muscle strength, reduced resistance and strength of quadriceps and increased functional limitation at 6MWT and CPET. VO 2 max was correlated with muscular variables and cardiac output. Bivariate linear regression models showed that the association between muscular structural and functional variables remained significant even after correcting for cardiac output. Conclusion: Our study showed the coexistence of ventilatory and quadriceps weakness in face of exercise intolerance in the same group of PAH patients. More interestingly, it is the first time that the independent association between muscular pattern and maximum exercise capacity is evidenced in PAH, independently of cardiac index highlighting the importance of considering rehabilitation in the treatment strategy for PAH.

OBJECTIVE: This study was designed to assess changes in skeletal muscle characteristics after 6 weeks' high-intensity physical training of patients with moderate to severe chronic obstructive pulmonary disease (COPD) and to determine how the changes were related to improvements in exercise tolerance and health related quality of life (HRQL). PATIENTS AND METHODS: Ten patients with a mean (SD) age of 60 (10) years and a forced expiratory volume in 1 second of 32% (9%) were enrolled. The effect of training on the 6-minute walk test, HRQL questionnaires, and skeletal muscles was examined for the 8 patients who completed the program. The structural and chemical characteristics of skeletal muscles before and after training were studied in vastus lateralis muscle biopsies. RESULTS: Training significantly modified the 6-minute walk test (P<.01), HRQL (P<.05), and citrate synthetase activity (P<.05). Changes in distances walked during the 6-minute walk test were significantly related to changes in the mean area of fibers (r=0.81). CONCLUSIONS: The results of this study indicate that 6 weeks of high-intensity physical training of COPD patients produces moderate changes in skeletal muscles which could partly explain improvements observed in exercise tolerance after respiratory rehabilitation.

The purpose of the study was to assess whether there are differences in cardiorespiratory fitness between children with and without cystic fibrosis (CF). Ten children with CF attended at a referral center for the treatment of CF and 13 children without CF were evaluated. The average age of the children with CF was 10.40 (3.13) years and those without CF was 9.39 (3.25) years. The children performed the three-minute step test with monitoring of hemodynamic parameters and the rating of perceived exertion (RPE) every minute. Oxygen desaturation of 4% during the test occurred in three children with CF and none of the children reached a SatO2 percentage &lt; 75%. After the step test, the findings showed that children with CF presented higher RPE scores during the test (p = 0.002) when compared to children without CF (p &lt; 0.001). The RPE was the only parameter that changed during the test and demonstrated that children with cystic fibrosis tired more during the test when compared to ch...

The present article reviews the physiological and performance effects of speed endurance training consisting of exercise bouts at near maximal intensities in already trained subjects. Despite a reduction in training volume, speed endurance training of endurance‐trained athletes can maintain the oxidative capacity and improve intense short‐duration/repeated high‐intensity exercise performance lasting 30 s to 4 min, as it occurs in a number of sports. When combined with a basic volume of training including some aerobic high‐intensity sessions, speed endurance training is also useful in enhancing performance during longer events, e.g. 40 K cycling and 10 K running. Athletes in team sports involving intense exercise actions and endurance aspects can also benefit from performing speed endurance training. These improvements don&#39;t appear to depend on changes in maximum oxygen uptake (), muscle substrate levels, glycolytic and oxidative enzymes activity, and membrane transport proteins ...

It is not known whether determinants of ventilation (VE)/volume of exhaled carbon dioxide (VCO2) slope during incremental exercise may differ at different stages of reduced ejection fraction chronic heart failure natural history. VE/VCO2 slope was fitted up to lowest VE/VCO2 ratio, that is, a proxy of the VE/perfusion ratio devoid of nonmetabolic stimuli to ventilatory drive. VE/VCO2 slope tertiles were generated from our database (&lt;27.5 [tertile 1], ≥27.5 to &lt;32.0 [tertile 2], and ≥32.0 [tertile 3]), and 147 chronic heart failure patients with repeated tests yielding VE/VCO2 slopes in 2 different tertiles were selected. Determinants of VE/VCO2 slope changes across tertile pairs 1 versus 2, 2 versus 3, and 1 versus 3 were assessed by exploring changes in VE and VCO2 at lowest VE/VCO2 and those in VE/work rate (W) and VCO2/W slope. Resting and peak cardiac output (CO) were calculated as VO2/estimated arteriovenous O2 difference and the CO/W slope analyzed. Notwithstanding a pro...

Cardiopulmonary exercise testing (CPET) is a methodology that has profoundly affected the approach to patients' functional evaluation, linking performance and physiological parameters to the underlying metabolic substratum and providing highly reproducible exercise capacity descriptors. This study provides professionals with an up-to-date review of the rationale sustaining the use of CPET for functional evaluation of cardiac patients in both the clinical and research settings, describing parameters obtainable either from ramp incremental or step constant-power CPET and illustrating the wealth of information obtainable through an experienced use of this powerful tool. The choice of parameters to be measured will depend on the specific goals of functional evaluation in the individual patient, namely, exercise tolerance assessment, training prescription, treatment efficacy evaluation, and/or investigation of exercise-induced adaptations of the oxygen transport/utilization system. The full potentialities of CPET in the clinical and research setting still remain largely underused and strong efforts are recommended to promote a more widespread use of CPET in the functional evaluation of cardiac patients. Eur J Cardiovasc Prev Rehabil 00:000-000

The Princeton Consensus (Expert Panel) Conference is a multispecialty collaborative tradition dedicated to optimizing sexual function and preserving cardiovascular health. The third Princeton Consensus met November 8 to 10, 2010, and had 2 primary objectives. The first objective focused on the evaluation and management of cardiovascular risk in men with erectile dysfunction (ED) and no known cardiovascular disease (CVD), with particular emphasis on identification of men with ED who may require additional cardiologic work-up. The second objective focused on reevaluation and modification of previous recommendations for evaluation of cardiac risk associated with sexual activity in men with known CVD. The Panel's recommendations build on those developed during the first and second Princeton Consensus Conferences, first emphasizing the use of exercise ability and stress testing to ensure that each man's cardiovascular health is consistent with the physical demands of sexual activity before prescribing treatment for ED, and second highlighting the link between ED and CVD, which may be asymptomatic and may benefit from cardiovascular risk reduction.

Patients who have undergone pneumonectomy (PNX) show limited exercise capacity, partly attributable to an impaired stroke index (SI). To determine whether this limitation is due to deconditioning, we assessed exercise performance and cardiopulmonary function in seven patients after PNX (age: 59 Ϯ 2 yr, mean Ϯ SEM) and eight normal, healthy nonsmokers (52 Ϯ 3 yr) before and after an ergometer exercise training program for 30 min per day, 5 d per week, for 8 wk at 65% of measured maximal O 2 uptake. Lung volume, diffusing capacity of carbon dioxide (D L CO ) and cardiac index (CI) were determined during steady-state exercise by a rebreathing method. Exercise endurance was measured at 80% of maximal power. As compared with normal subjects, patients who had had PNX showed diminished maximal oxygen uptake ( O 2max ), as well as diminished lung volumes, ventilatory capacities, and maximal cardiac and stroke indexes. After training, O 2max , endurance, and peripheral O 2 extraction improved in both groups. However, maximal cardiac and stroke indexes increased only in normal subjects and not in patients. We conclude that an irreversibly fixed maximal SI is a major source of exercise limitation after PNX, probably because of pulmonary arterial hypertension and ր or mechanical distortion of the cardiac fossa. Ventilatory impairment after PNX did not prevent a traininginduced increase in O 2max . Exercise training confers significant functional benefit on postpneumonectomy patients by enhancing peripheral O 2 extraction. Hijazi OM, Ramanathan M, Estrera AS, Peshock RM, Hsia CCW. Fixed maximal stroke index in patients after pneumonectomy.

Impaired exercise capacity is common after the Fontan procedure and is attributed to cardiovascular limits. The Fontan circulation, however, is also distinctively vulnerable to unfavorable lung mechanics. This study aimed to define the prevalence and physiological relevance of pulmonary dysfunction in patients with Fontan physiology. We analyzed data from the Pediatric Heart Network Fontan Cross-Sectional Study to assess the prevalence and pattern of abnormal spirometry in Fontan patients (6-18 yr old) and investigated the relationship between low forced vital capacity (FVC) and maximum exercise variables, including peak O2 consumption (Vo2peak), among those who demonstrated adequate effort (n = 260). Average ages at the time of exercise testing and Fontan completion were 13.2 ± 3.0 and 3.5 ± 2.2 yr old, respectively. Aerobic capacity was reduced (Vo2peak: 67.3 ± 15.6% predicted). FVC averaged 79.0 ± 14.8% predicted, with 45.8% having a FVC less then the lower limit of normal. Only ...

It has been demonstrated in numerous studies that N-terminal pro-B-type natriuretic peptide (NT-proBNP) is strongly associated with left ventricular ejection fraction (LVEF), functional capacity (FC), and cardiovascular (CV) mortality in heart failure (HF) patients. The aim of the present study was to determine the predictive cutoff values of NT-proBNP for predicting these parameters. One hundred HF patients (88 male, 12 female, mean age 53.6 +/- 8.9 years) with left ventricular (LV) systolic dysfunction and impaired exercise capacity were enrolled into the study. Echocardiographic examination was performed. The NT-proBNP concentration was measured after resting for 20 min in the supine position. The modified Bruce protocol was utilized for exercise testing. The patients were followed for between 690 and 840 days (mean 750 +/- 30 days) for the occurrence of CV events. There was a strong negative correlation between NT-proBNP concentration and LVEF (p &lt; 0.004). It was found that N...

Resistance training has become a mainstay of exercise training in type 2 diabetes mellitus (T2DM). However, it remains controversial whether hypertrophy resistance training (HRT) is superior to endurance resistance training (ERT) with regard to its effects on glycaemic control, muscle mass and strength. Thirty-two patients with T2DM (13 men and 19 women; 64.8 ± 7.8 years) were randomly assigned to either eight weeks of HRT (n = 16; 2 sets, 10-12 repetitions, 70% of the one-repetition maximum (1-RM)) or ERT (n = 16; 2 sets, 25-30 repetitions, 40% 1-RM). In addition, all patients participated in aerobic exercise training (AET; 1 hour/day on 2 non-consecutive days/week; cycle ergometer; 70% of heart rate reserve). After eight weeks of intervention, there were time but not group effects for reduced glucose and fructosamine levels, weight, BMI, waist circumference, subcutaneous abdominal fat, resting heart rate, systolic and diastolic blood pressure; muscle mass of the arms and physical ...

Restoration of walking capacity, as reflected by walking speed and walking distance, is a primary goal after stroke. Peak aerobic capacity (peak oxygen consumption [V̇o2peak]) is suggested to be correlated with walking capacity after stroke. Although the strength of this correlation is unclear, physical therapy programs often target walking capacity by means of aerobic training. The purpose of this systematic review was to summarize the available evidence on the correlation between V̇o2peak and walking capacity. The databases MEDLINE, CINAHL, EMBASE, Cochrane Library, and SPORTDiscus were searched up to May 2014. Cross-sectional studies reporting correlation coefficients between V̇o2peak and walking capacity in stroke were included, along with longitudinal studies reporting these correlation coefficients at baseline. The methodological quality of the studies was assessed using a checklist of 27 items for observational research. Information on study design, stroke severity and recove...

In preparation for clinical trials of basic fibroblast growth factor (bFGF) to treat ischemic heart disease, we sought to identify a clinically feasible method of bFGF administration. BACKGROUND Basic FGF has been shown to promote collateral development after experimentally induced coronary occlusion; however, methods of bFGF delivery that have been shown to be effective in previous investigations would not be practical for clinical use. Four randomized, blinded, controlled investigations were conducted independently and sequentially in an established canine model. For all studies, dogs underwent operative placement of proximal left circumflex coronary artery ameroid constrictors. The four investigational regimens included: 1) bFGF by central venous bolus injection, 1,740 g/day for one, two or seven days; 2) bFGF by intravenous infusion, 100 g/kg body weight per day for seven days; 3) bFGF by pericardial instillation, 2,000 g/day for 7 days; and 4) bFGF by intracoronary injection (Judkin's technique), 100 g/kg per day for one or two days. Each substudy included a contemporaneous vehicle control group. Collateral perfusion (microspheres) was assessed during maximal coronary vasodilation during the first month after ameroid placement. Maximal collateral perfusion in dogs that received intracoronary bFGF for two days exceeded that of concurrent control dogs by 31% (p Ͻ 0.01). Perfusion was not increased in dogs that received single-dose intracoronary bFGF. Basic FGF administration by central venous bolus injection, intravenous infusion and pericardial injection failed to enhance collateral perfusion. CONCLUSIONS Administration of bFGF by the intracoronary route, an intervention that is feasible in patients, augments collateral development in dogs. These data provide a rationale for clinical testing of intracoronary bFGF in ischemic heart disease. (

Background: The aim of this study was to define clinical characteristics of patients with COPD and PH with particular attention on subgroup which have PH “out of proportion”, investigating the differences in term of inflammatory and oxidative stress status. Materials and Methods: Patients with COPD and low level of oxygen (PaO2 2), who showed, at echocardiographic study, PAPs &gt; 30 mmHg without left heart systolic and diastolic dysfunction underwent to Right Heart Catheterization (RHC) to evaluate pulmonary pressures. The assay for human IL-6, LTB4, VIP and ET-1 were performed on blood sample taken during RHC in pulmonary artery. Results: 83 patients were enrolled and divided in three groups: simple COPD when mPAP was less then 25 mmHg (37 pz); COPD with PH if mPAP &gt; 25 mmHg (46 pz) and among these last ones who had mPAP &gt;35mmHg and FEV1 Patients with PH were older and had a BMI higher than others groups, moreover they had lower FEV1 and DLCO. Despite these differences, lowe...

Objective: To investigate the effects of low-intensity wheelchair training on wheelchair-specific fitness, wheelchair skill performance and physical activity levels in inactive people with long-term spinal cord injury. Design: Randomized controlled trial. Participants: Inactive manual wheelchair users with spinal cord injury for at least 10 years (n = 29), allocated to exercise (n = 14) or no exercise. Methods: The 16-week training consisted of wheelchair treadmill-propulsion at 30-40% heart rate reserve or equivalent in terms of rate of perceived exertion, twice a week, for 30 min per session. Wheelchair-specific fitness was determined as the highest 5-s power output over 15-m overground wheelchair sprinting (P5-15m), isometric push-force, submaximal fitness and peak aerobic work capacity. Skill was determined as performance time, ability and strain scores over a wheelchair circuit. Activity was determined using a questionnaire and an odometer. Results: Significant training effects appeared only in P5-15m (exercise vs control: mean +2.0 W vs -0.7 W, p = 0.017, r u =0.65). Conclusion: The low-intensity wheelchair training appeared insufficient for substantial effects in the sample of inactive people with long-term spinal cord injury, presumably in part owing to a too-low exercise frequency. Effective yet feasible and sustainable training, as well as other physical activity programmes remain to be developed for inactive people with long-term spinal cord injury.

Pulmonary hypertension (PH) is a disease with a poor prognosis characterized by a vascular remodeling process and an increase in pulmonary vascular resistance. While a variety of reports demonstrated that exercise training exerts beneficial effects on exercise performance and quality of life in PH patients, it is not known how physical exercise affects vascular remodeling processes occurring in hypoxia-induced PH. Therefore, we investigated the effect of individualized exercise training on the development of hypoxia-induced PH in mice. Training effects were compared with pharmacological treatment with the phosphodiesterase 5 inhibitor Sildenafil or a combination of training plus Sildenafil. Trained mice who received Sildenafil showed a significantly improved walking distance (from 88.9 ± 8.1 to 146.4 ± 13.1 m) and maximum oxygen consumption (from 93.3 ± 2.9 to 105.5 ± 2.2% in combination with Sildenafil, to 102.2 ± 3.0% with placebo) compared with sedentary controls. Right ventricul...

The New York Heart Association (NYHA) functional class is a subjective estimate of a patient's functional ability based on symptoms that does not always correlate with the objective estimate of functional capacity, peak oxygen consumption (peak VO 2 ). Additionally, relationships between these two measurements have not been examined in the current medical era when patients are using beta blockers, aldosterone antagonists, and cardiac resynchronization therapy (CRT). Using baseline data from the HF-ACTION (Heart Failure and A Controlled Trial Investigating Outcomes of Exercise TraiNing) study, we examined this relationship. Methods-1758 patients underwent a symptom limited metabolic stress test and stopped exercise due to dyspnea or fatigue. The relationship between NYHA functional class and peak VO 2 was examined. Additionally, the effects of beta blockers, aldosterone antagonists, and CRT therapy on these relationships were compared. Results-NYHA II patients have a significantly higher peak VO 2 (16.1 ± 4.6 vs. 13.0 ± 4.2 ml/kg/ min), a lower Ve/VCO 2 slope (32.8 ± 7.7 versus 36.8 ± 10.4), and a longer duration of exercise (11.0 ± 3.9 versus 8.0 ± 3.4 minutes) than NYHA III/IV patients. Within each functional class, there is no difference in any of the exercise parameters between patients on or off of beta blockers, aldosterone

Patients with COPD may experience respiratory muscle weakness. Two therapeutic approaches to the respiratory muscles are inspiratory muscle training and calisthenics-and-breathing exercises. The aims of the study are to compare the effects of inspiratory muscle training and calisthenics-and-breathing exercises associated with physical training in subjects with COPD as an additional benefit of strength and endurance of the inspiratory muscles, thoracoabdominal mobility, physical exercise capacity, and reduction in dyspnea on exertion. In addition, these gains were compared between subjects with and without respiratory muscle weakness. 25 subjects completed the study: 13 composed the inspiratory muscle training group, and 12 composed the calisthenics-and-breathing exercises group. Subjects were assessed before and after training by spirometry, measurements of respiratory muscle strength and test of inspiratory muscle endurance, thoracoabdominal excursion measurements, and the 6-min wa...

Komorbit faktörleri fazla olan, yaşlı ve riskli hastalarda cerrahi mortalite oldukça yüksektir. Kısa aortik kros klemp zamanı (AKKZ) ve total perfüzyon zamanı (TPZ)'nın yanında, dikişe bağlı gelişebilecek komplikasyonların önüne geçilmesi açısından da standart aort kapak replasmanına kıyasla dikişsiz aort kapak replasmanının daha uygun bir tedavi yöntemi olduğunu düşünmekteyiz. Kliniğimizde ciddi aort darlığı nedeniyle opere edilen iki vakayı literatür eşliğinde sunmayı planladık.

Ozet Komorbit faktorleri fazla olan, yasli ve riskli hastalarda cerrahi mortalite oldukca yuksektir. Kisa aortik kros klemp zamani (AKKZ) ve total perfuzyon zamani (TPZ)’nin yaninda, dikise bagli gelisebilecek komplikasyonlarin onune gecilmesi acisindan da standart aort kapak replasmanina kiyasla dikissiz aort kapak replasmaninin daha uygun bir tedavi yontemi oldugunu dusunmekteyiz. Klinigimizde ciddi aort darligi nedeniyle opere edilen iki vakayi literatur esliginde sunmayi planladik.

A flow-dependent conical positive expiratory pressure (PEP) resistor incorporated into a oronasal mask was developed, which might reduce dyspnea and dynamic hyperinflation and increase exercise endurance for patients with COPD. We reported here the flow-pressure relationships and the safety and suitability of the device when used by healthy young and older subjects. The flow-pressure relationships were determined for a range of resistors with different orifice diameters and cone lengths. A 1-cm conical-PEP device with a 6- or 7-mm orifice was used during a cycle exercise test (60% heart rate reserve) in 15 young (mean ± SD, 24.3 ± 3.9 y) and 12 older (mean ± SD, 64.4 ± 3.5 y) adults. Cardiopulmonary function and dyspnea were monitored for up to 10 min of exercise. For a given flow, pressure decreased as the cone length and orifice size increased. A 1-cm cone with a 6 mm orifice generated pressures of 5.24 ± 0.17 cm HO and 18.29 ± 0.34 cm HO at flows of 0.5 and 0.9 L/s, while for a 7...

OBJECTIVE: To determine the sex-specific relationships between glucose intolerance and Shwachman-Kulczycki clinical score, lung function, Brasfield chest-radiograph score, and exercise capacity in patients with cystic fibrosis (CF). METHODS: We used a cross-sectional study design and included CF patients > 10 years old. All patients had clinical and nutritional evaluation, oral glucose tolerance test, spirometry, chest radiograph, and 6-min walk test (6MWT). Patients were classified as having normal glucose tolerance, impaired glucose tolerance, or CF-related diabetes mellitus. RESULTS: We included 88 patients: 59 with normal glucose tolerance, 15 with impaired glucose tolerance, and 14 with CF-related diabetes. Shwachman-Kulczycki clinical score (P ‫؍‬ .04), at-rest S pO 2 (P ‫؍‬ .001), S pO 2 difference before versus after 6MWT (P ‫؍‬ .001), and Brasfield chest-radiograph score (P ‫؍‬ .01) were significantly lower in the impaired-glucose-tolerance group than in the normal-glucosetolerance group, but did not differ from the CF-related-diabetes group. In female patients only, percentof-predicted FEV 1 was significantly lower in the impaired-glucose-tolerance group than in the normalglucose-tolerance group (P ‫؍‬ .02), but did not differ from the CF-related-diabetes group (P ‫؍‬ .10). There was a significant relationship between glucose intolerance and sex when clinical score, 6-min walk distance, FEV 1 , and radiograph score were combined in a multivariate analysis. CONCLUSIONS: In patients with CF, glucose intolerance was associated with poor clinical score, lower at-rest S pO 2 , greater S pO 2 difference before versus after 6MWT, poor lung function, and lower radiograph score. Overall, multivariate analysis indicated poorer performance in the latter variables in female patients with glucose intolerance than in male patients with glucose intolerance.

Over the past century, understanding the mechanisms underlying muscle fatigue and weakness has been the focus of much investigation. However, the dominant theory in the field, that lactic acidosis causes muscle fatigue, is unlikely to tell the whole story. Recently, dysregulation of sarcoplasmic reticulum (SR) Ca 2+ release has been associated with impaired muscle function induced by a wide range of stressors, from dystrophy to heart failure to muscle fatigue. Here, we address current understandings of the altered regulation of SR Ca 2+ release during chronic stress, focusing on the role of the SR Ca 2+ release channel known as the type 1 ryanodine receptor.

TO THE EDITOR: Fatigue during exercise is a complex phenomenon and has historically been assigned to peripheral mechanisms. Recently more attention is paid to the "central" origin of fatigue, where failure of the motor cortex, changing neurotransmitter concentrations, decreased blood flow, etc., are put forward as underlying mechanisms (3). Both hypotheses (peripheral and central) contain the same "mistake" when isolating the head from the body and vice versa. In their Viewpoint, Robertson and Marino (4) link the prefrontal cortex (PFC) with exercise tolerance and possible fatigue. The PFC could play a role as switchboard during exhaustive exercise, taking part in "decision" making on exercise cessation (4). A declined EEG response to exercise was found in the PFC when exercise intensity increased (5), which confirms previous results with exhaustive exercise in the heat (2). This might indicate that electrocortical activity is diminished at exercise cessation or that other brain areas become more "active" (1). The important message of the recent paper ( ) is that the authors clearly try to explain that the brain integrates several signals and emotions. However, the question remains if the brain really "thinks" and "makes decisions" to avoid catastrophe. It might also be that during exercise the disturbance of peripheral and central homeostasis are integrated and that several neurotransmitter systems influencing frontal and other brain regions overshoot or even become depleted at exhaustion (3). Also, temporary depletion of brain substrates (glucose, glycogen, lactate) could be involved. At this stage we probably don't have the right tools (methods) available to confirm or reject this hypothesis.

Karinen, Heikki, Juha E. Peltonen, Mika Ka ¨ho ¨nen, and Heikki O. Tikkanen. Prediction of acute mountain sickness by monitoring arterial saturation during ascent. High Alt. Med. Biol. 11:325-332, 2010.-Acute mountain sickness (AMS) is a common problem while ascending at high altitude. AMS may progress rapidly to fatal results if the acclimatization process fails or symptoms are neglected and the ascent continues. Extensively reduced arterial oxygen saturation at rest (R-Spo 2 ) has been proposed as an indicator of inadequate acclimatization and impending AMS. We hypothesized that climbers less likely to develop AMS on further ascent would have higher Spo 2 immediately after exercise (Ex-Spo 2 ) at high altitudes than their counterparts and that these postexercise measurements would provide additional value for resting measurements to plan safe ascent. The study was conducted during eight expeditions with 83 ascents. We measured R-Spo 2 and Ex-Spo 2 after moderate daily exercise [50 m walking, target heart rate (HR) 150 bpm] at altitudes of 2400 to 5300 m during ascent. The Lake Louise Questionnaire was used in the diagnosis of AMS. Ex-Spo 2 was lower at all altitudes among those climbers suffering from AMS during the expeditions than among those climbers who did not get AMS at any altitude during the expeditions. Reduced R-Spo 2 and Ex-Spo 2 measured at altitudes of 3500 and 4300 m seem to predict impending AMS at altitudes of 4300 m ( p < 0.05 and p < 0.01) and 5300 m (both p < 0.01). Elevated resting HR did not predict impending AMS at these altitudes. Better aerobic capacity, younger age, and higher body mass index (BMI) were also associated with AMS (all p < 0.01). In conclusion, those climbers who successfully maintain their oxygen saturation at rest, especially during exercise, most likely do not develop AMS. The results suggest that daily evaluation of Spo 2 during ascent both at rest and during exercise can help to identify a population that does well at altitude.

O objetivo deste estudo foi correlacionar medidas ultrassonograficas do quadriceps femoral com o nivel de dispneia e a gravidade de pacientes com doenca pulmonar obstrutiva cronica. Realizado estudo observacional, descritivo e transversal.  A amostra foi composta de 41 individuos, sendo 30 do sexo masculino e 11 do sexo feminino. Os pacientes foram classificados segundo a gravidade da doenca e o grau de dispneia. Foram realizadas medidas ultrassonograficas do quadriceps femoral (area seccional, circunferencia e espessura). Os pacientes apresentaram area de seccao transversa media de 5,70 cm 2 , espessura media de 2,33 cm e circunferencia media de 11,72 cm. Os pacientes mais graves tiveram medias menores de area e espessura, mas nao de circunferencia. Aqueles com dispneia mais avancada apresentaram tendencia de reducao da area do quadriceps femoral, sem significância estatistica.

Rationale: Chronic obstructive pulmonary disease (COPD) is a progressive, smoking-related, inflammatory lung disease in which tumor necrosis factor-␣ is overexpressed and has been suggested to play a pathogenic role. Objectives: To determine if infliximab, an anti-TNF-␣ antibody, results in clinical benefit and has an acceptable safety profile in patients with moderate to severe COPD. Methods: In a multicenter, randomized, double-blind, placebocontrolled, parallel-group, dose-finding study, subjects with moderate to severe COPD received infliximab (3 mg/kg [n ϭ 78] or 5 mg/kg [n ϭ 79]) or placebo (n ϭ 77) at Weeks 0, 2, 6, 12, 18, and 24. Efficacy, health status, and safety were assessed through Week 44. Measurements and Main Results: Infliximab was generally well tolerated, but showed no treatment benefit as measured by the primary endpoint, Chronic Respiratory Questionnaire total score. Similarly, there was no change in secondary measures, including prebronchodilator FEV 1 , 6-min walk distance, SF-36 physical score, transition dyspnea index, or moderate-to-severe COPD exacerbations. Post hoc analysis revealed that subjects who were younger or cachectic showed improvement in the 6-min walk distance. Malignancies were diagnosed during the study in 9 of 157 infliximab-treated subjects versus 1 of 77 placebo-treated subjects. No opportunistic infections were observed, and there were no differences in the occurrence of antibiotic-requiring infections, although the incidence of pneumonia was higher in infliximab-treated subjects. No infection-related mortality was observed. Higher proportions of infliximab-treated subjects discontinued the study agent due to adverse events (20-27%) than did placebo-treated subjects (9%). Conclusions: Subjects with moderate to severe COPD did not benefit from treatment with infliximab. Although not statistically significant, more cases of cancer and pneumonia were observed in the infliximab-treated subjects. The impact of infliximab on malignancy risk in patients with COPD needs to be further elucidated.

It is commonly agreed that one needs to use a threshold value in the detection of muscle activity timing in electromyographic (EMG) signal analysis. However, the algorithm for threshold determination lacks an agreement between the investigators. In this study we aimed to determine a proper threshold value in an incremental cycling exercise for accurate EMG signal analysis. Nine healthy recreationally active male subjects cycled until exhaustion. EMG recordings were performed on four low extremity muscle groups; gastrocnemius lateralis (GL), gastrocnemius medialis (GM), soleus (SOL) and vastus medialis (VM). We have analyzed our data using three different threshold levels: 25%, 35% and 45% of the mean RMS EMG value. We compared the appropriateness of these threshold values using two criteria: (1) significant correlation between the actual and estimated number of bursts and (2) proximity of the regression line of the actual and estimated number of bursts to the line of identity. It had been possible to find a significant correlation between the actual and estimated number of bursts with the 25, 35 and 45% threshold values for the GL muscle. Correlation analyses for the VM muscle had shown that the number of bursts estimated with the 35% threshold value was found to be significantly correlated with the actual number of bursts. For the GM muscle, it had been possible to predict the burst number by using either the 35% or 45% threshold value and for the SOL muscle the 25% threshold value was found as the best predictor for actual number of burst estimation. Detailed analyses of the actual and estimated number of bursts had shown that success of threshold estimation may differ among muscle groups. Evaluation of our data had clearly shown that it is important to select proper threshold values for correct EMG signal analyses. Using a single threshold value for different exercise intensities and different muscle groups may cause misleading results.

Background-The burden of cardiovascular disease world-wide is one of great concern to patients and health care agencies alike. Traditionally centre-based cardiac rehabilitation (CR) programmes are offered to individuals after cardiac events to aid recovery and prevent further cardiac illness. Home-based cardiac rehabilitation programmes have been introduced in an attempt to widen access and participation. -To determine the effectiveness of home-based cardiac rehabilitation programmes compared with supervised centre-based cardiac rehabilitation on mortality and morbidity, healthrelated quality of life and modifiable cardiac risk factors in patients with coronary heart disease. Search methods-We updated the search of a previous review by searching the Cochrane Central Register of Controlled Trials (CENTRAL) in The Cochrane Library (2007, Issue 4), MEDLINE, EMBASE and CINAHL from 2001 to January 2008. We checked reference lists and sought advice from experts. No language restrictions were applied. Selection criteria-Randomised controlled trials (RCTs) that compared centre-based cardiac rehabilitation (e.g. hospital, gymnasium, sports centre) with home-based programmes, in adults with myocardial infarction, angina, heart failure or who had undergone revascularisation.

Background Uncontrolled studies suggested that aerosolized iloprost, a stable analogue of prostacyclin, causes selective pulmonary vasodilatation and improves hemodynamics and exercise capacity in patients with pulmonary hypertension. We compared repeated daily inhalations of 2.5 or 5.0 µg of iloprost (six or nine times per day; median inhaled dose, 30 µg per day) with inhalation of placebo. A total of 203 patients with selected forms of severe pulmonary arterial hypertension and chronic thromboembolic pulmonary hypertension (New York Heart Association [NYHA] functional class III or IV) were included. The primary end point was met if, after week 12, the NYHA class and distance walked in six minutes were improved by at least one class and at least 10 percent, respectively, in the absence of clinical deterioration according to predefined criteria and death. The combined clinical end point was met by 16.8 percent of the patients receiving iloprost, as compared with 4.9 percent of the patients receiving placebo (P=0.007). There were increases in the distance walked in six minutes of 36.4 m in the iloprost group as a whole (P=0.004) and of 58.8 m in the subgroup of patients with primary pulmonary hypertension. Overall, 4.0 percent of patients in the iloprost group (including one who died) and 13.7 percent of those in the placebo group (including four who died) did not complete the study (P=0.024); the most common reason for withdrawal was clinical deterioration. As compared with base-line values, hemodynamic values were significantly improved at 12 weeks when measured after iloprost inhalation (P<0.001), were largely unchanged when measured before iloprost inhalation, and were significantly worse in the placebo group. Further significant beneficial effects of iloprost treatment included an improvement in the NYHA class (P=0.03), dyspnea (P=0.015), and quality of life (P= 0.026). Syncope occurred with similar frequency in the two groups but was more frequently rated as serious in the iloprost group, although this adverse effect was not associated with clinical deterioration. Inhaled iloprost is an effective thera- py for patients with severe pulmonary hypertension.

Increased plasma nitrate concentrations from dietary sources of nitrate have proven to benefit exercise performance. Beetroot (BR) contains relatively high levels of nitrate (NO3−), which increases nitric oxide stores. This study investigated whether dietary nitrate supplementation, in the form of a BR beverage, would improve rowing performance during ergometer repetitions. In a randomized crossover design, 14 well-trained junior male rowers consumed 500 ml of either BR or placebo (PL) daily for 6 d. After supplementation, rowers completed 6 maximal 500-m ergometer repetitions and times were recorded. A 7-d washout period separated the 2 trials. Blood pressure, oxygen saturation, maximum heart rate, urine (specific gravity, pH, and nitrites), and lactates were collected for analysis at baseline and pre- and postperformance. Changes in the mean with 95% confidence limits were calculated. There was a likely benefit to average repetition time in the BR condition, compared with PL (0.4%...