1,721,394 research outputs found
Functional electrical stimulation for chronic heart failure: A meta-analysis
No full textINTRODUCTION:
We conducted a meta-analysis of randomized, controlled trials of combined electrical stimulation versus conventional exercise training or placebo control in heart failure patients.
METHODS:
A systematic search was conducted of Medline (Ovid) (1950-September 2011), Embase.com (1974-September 2011), Cochrane Central Register of Controlled Trials and CINAHL (1981-September 2011). The search strategy included a mix of MeSH and free text terms for the key concepts heart failure, exercise training and functional electrical stimulation (FES).
RESULTS:
FES produced inferior improvements in peak VO2 when compared to cycle training: mean difference (MD) -0.32 ml.kg(-1).min(-1) (95% C.I. -0.63 to -0.02 ml.kg(-1).min(-1), p=0.04), however FES elicited superior improvements in peak VO2: MD 2.30 ml.kg(-1).min(-1) (95% C.I. 1.98 to 2.62 ml.kg(-1).min(-1), p<0.00001); and six minute walk distance to sedentary care or sham FES; MD 46.9 m (95% C.I. 22.5 to 71.3m, p=0.0002). There was no difference in change in quality of life between cycling and FES, but FES elicited significantly larger improvements in Minnesota Living with Heart Failure score than placebo or sham treatment; MD 1.15 (95% C.I. 0.69 to 1.61, p<0.00001). Moreover, the total FES intervention hours were strongly correlated with change in peak VO2, (r=0.80, p=0.02).
CONCLUSIONS:
Passive or active exercise is beneficial for patients with moderate to severe heart failure, but active cycling, or other aerobic/resistance activity is preferred in patients with heart failure who are able to exercise, and FES is the preferred modality in those unable to actively exercise. The benefits of FES may however, be smaller than those observed in conventional exercise training. Aggregate hours of electrical stimulation therapy were associated with larger improvements in cardio-respiratory fitness
Efficacy of inspiratory muscle training in chronic heart failure patients: A systematic review and meta-analysis
No full textINTRODUCTION:
Inspiratory muscle training (IMT) offers an alternative to exercise training (ExT) in the most severely deconditioned heart failure patients who are unable to exercise. We conducted a meta-analysis to determine magnitude of change in peak VO2, six minute walk distance (6MWD), Quality of Life measured by the Minnesota Living with Heart Failure Questionnaire (MLWHFQ), maximal inspiratory pressure (PI max) and ventilatory equivalent for carbon dioxide (VE/VCO2 slope) with IMT.
METHODS:
A systematic search was conducted of randomized, controlled trials of IMT therapy in CHF patients using Medline (Ovid) (1950-February 2012), Embase.com (1974-February 2012), Cochrane Central Register of Controlled Trials and CINAHL (1981-February 2012). The search strategy included a mix of MeSH and free text terms for the key concepts heart failure, inspiratory or respiratory muscle training, exercise training
RESULTS:
The eleven included studies contained data on 287 participants: 148 IMT participants and 139 sham or sedentary control. Compared to control groups, CHF patients undergoing IMT showed a significant improvement in peak VO2 (+1.83 ml kg(-1) min(-1), 95% C.I. 1.33 to 2.32 ml kg(-1) min(-1), p<0.00001); 6 MWD (+34.35 m, 95% C.I. 22.45 to 46.24 m, p<0.00001); MLWHFQ (-12.25, 95% C.I. -17.08 to -7.43, p<0.00001); PImax (+20.01, 95% C.I. 13.96 to 26.06, p<0.00001); and VE/VCO2 slope (-2.28, 95% C.I. -3.25 to -1.30, p<0.00001).
CONCLUSIONS:
IMT improves cardio-respiratory fitness and quality of life to a similar magnitude to conventional exercise training and may provide an initial alternative to the more severely de-conditioned CHF patients who may then transition to conventional ExT
Intermittent versus continuous exercise training in chronic heart failure: A meta-analysis
No full textINTRODUCTION:
We conducted a meta-analysis of randomized, controlled trials of combined strength and intermittent aerobic training, intermittent aerobic training only and continuous exercise training in heart failure patients.
METHODS:
A systematic search was conducted of Medline (Ovid) (1950-September 2011), Embase.com (1974-September 2011), Cochrane Central Register of Controlled Trials and CINAHL (1981-September 19 2011). The search strategy included a mix of MeSH and free text terms for the key concepts heart failure, exercise training, interval training and intermittent exercise training.
RESULTS:
The included studies contained an aggregate of 446 patients, 212 completed intermittent exercise training, 66 only continuous exercise training, 59 completed combined intermittent and strength training and 109 sedentary controls. Weighted mean difference (MD) in Peak VO2 was 1.04mlkg(-1)min(-1) and (95% C.I.) was 0.42-1.66 (p=0.0009) in intermittent versus continuous exercise training respectively. Weighted mean difference in Peak VO2 was -1.10mlkg(-1)min(-1) (95% C.I.) was -1.83-0.37 p=0.003 for intermittent only versus intermittent and strength (combined) training respectively. In studies reporting VE/VCO2 for intermittent versus control groups, MD was -1.50 [(95% C.I. -2.64, -0.37), p=0.01] and for intermittent versus continuous exercise training MD was -1.35 [(95% C.I. -2.15, -0.55), p=0.001]. Change in peak VO2 was positively correlated with weekly exercise energy expenditure for intermittent exercise groups (r=0.48, p=0.05).
CONCLUSIONS:
Combined strength and intermittent exercise appears superior for peak VO2 changes when compared to intermittent exercise of similar exercise energy expenditure
Clinical outcomes and cardiovascular responses to exercise training in heart failure patients with preserved ejection fraction: A systematic review and meta-analysis
No full textExercise training induces physical adaptations for heart failure patients with systolic dysfunction, but less is known about those patients with preserved ejection fraction. To establish whether exercise training produces changes in peak V̇o2 and related measures, quality of life, general health, and diastolic function in heart failure patients with preserved ejection fraction. We conducted a MEDLINE search (1985 to October 10, 2014), for exercise-based rehabilitation trials in heart failure, using search terms "exercise training, heart failure with preserved ejection fraction, heart failure with normal ejection fraction, peak V̇o2, and diastolic heart dysfunction". Seven intervention studies were included providing a total of 144 exercising subjects and 114 control subjects, a total of 258 participants. Peak V̇o2 increased by a mean difference (MD) 2.13 ml·kg(-1)·min(-1) [95% confidence interval (CI) 1.54 to 2.71, P < 0.00001] in exercise training vs. sedentary control, equating to a 17% improvement from baseline. The corresponding data are provided for the following exercise test variables: V̇e/V̇co2 slope, MD 0.85 ml·kg(-1)·min(-1) (95% CI 0.05 to 1.65, P = 0.04); maximum heart rate, MD 5.60 beats per minute (95% CI 3.95 to 7.25, P < 0.00001); Six-Minute Walk Test, MD 32.1 m (95% CI 17.2 to 47.1, P < 0.0001); and indices of diastolic function: E/A ratio, MD 0.07 (95% CI 0.02 to 0.12, P = 0.005); E/E' ratio MD -2.31 (95% CI -3.44 to -1.19, P < 0.0001); deceleration time (DT), MD -13.2 ms (95% CI -19.8 to -6.5, P = 0.0001); and quality of life: Minnesota Living with Heart Failure Questionnaire, MD -6.50 (95% CI -9.47 to -3.53, P < 0.0001); and short form-36 health survey (physical dimension), MD 15.6 (95% CI 7.4 to 23.8, P = 0.0002). In 3,744 h patient-hours of training, not one death was directly attributable to exercise. Exercise training appears to effect several health-related improvements in people with heart failure and preserved ejection fraction
Resistance training and sarcopenia
Full text linkAging is inexorably accompanied by a progressive decline of muscle mass, quality and strength. The resulting condition has been termed sarcopenia. Age-related sarcopenia can be accelerated by a variety of factors including changes in the hormonal milieu, inactivity, poor nutrition, chronic illness, and loss of integrity and function in the peripheral and central nervous systems. The downstream mechanisms by which these risk factors cause sarcopenia are not completely understood. Exercise training (particularly resistance training) has long been identified as the most promising method for increasing muscle mass and strength among older people. New interventions aimed at preventing muscle atrophy, promoting muscle growth and ultimately, maintaining muscle functions during aging are discussed. Understanding how age affects muscle-related gene expression, protein recycling and resynthesis, post-translational modification and turnover will be crucial to identify new treatment options
Exercise training modalities in chronic heart failure: Does high intensity aerobic interval training make the difference?
Full text linkExercise training (ET) is strongly recommended in patients with chronic heart failure (CHF). Moderate-intensity aerobic continuous ET is the best established training modality in CHF patients. In the last decade, however, high-intensity interval exercise training (HIIT) has aroused considerable interest in cardiac rehabilitation community. Basically, HIIT consists of repeated bouts of high-intensity exercise alternated with recovery periods. In CHF patients, HIIT exerts larger improvements in exercise capacity compared to moderate-continuous ET. These results are intriguing, mostly considering that better functional capacity translates into an improvement of symptoms and quality of life. Notably, HIIT did not reveal major safety issues; although CHF patients should be clinically stable, have had recent exposure to at least regular moderate-intensity exercise, and appropriate supervision and monitoring during and after the exercise session are mandatory. The impact of HIIT on cardiac dimensions and function and on endothelial function remains uncertain. HIIT should not replace other training modalities in heart failure but should rather complement them. Combining and tailoring different ET modalities according to each patient's baseline clinical characteristics (i.e. exercise capacity, personal needs, preferences and goals) seem the most astute approach to exercise prescription
Exercise training in heart failure patients with preserved ejection fraction: a systematic review and meta-analysis
Full text linkGriffith Health, School of Medical ScienceFull Tex
Comparison of Medical Research Abstracts Written by Surgical Trainees and Senior Surgeons or Generated by Large Language Models
No full textImportance: Artificial intelligence (AI) has permeated academia, especially OpenAI Chat Generative Pretrained Transformer (ChatGPT), a large language model. However, little has been reported on its use in medical research. Objective: To assess a chatbot's capability to generate and grade medical research abstracts. Design, Setting, and Participants: In this cross-sectional study, ChatGPT versions 3.5 and 4.0 (referred to as chatbot 1 and chatbot 2) were coached to generate 10 abstracts by providing background literature, prompts, analyzed data for each topic, and 10 previously presented, unassociated abstracts to serve as models. The study was conducted between August 2023 and February 2024 (including data analysis). Exposure: Abstract versions utilizing the same topic and data were written by a surgical trainee or a senior physician or generated by chatbot 1 and chatbot 2 for comparison. The 10 training abstracts were written by 8 surgical residents or fellows, edited by the same senior surgeon, at a high-volume hospital in the Southeastern US with an emphasis on outcomes-based research. Abstract comparison was then based on 10 abstracts written by 5 surgical trainees within the first 6 months of their research year, edited by the same senior author. Main Outcomes and Measures: The primary outcome measurements were the abstract grades using 10- and 20-point scales and ranks (first to fourth). Abstract versions by chatbot 1, chatbot 2, junior residents, and the senior author were compared and judged by blinded surgeon-reviewers as well as both chatbot models. Five academic attending surgeons from Denmark, the UK, and the US, with extensive experience in surgical organizations, research, and abstract evaluation served as reviewers. Results: Surgeon-reviewers were unable to differentiate between abstract versions. Each reviewer ranked an AI-generated version first at least once. Abstracts demonstrated no difference in their median (IQR) 10-point scores (resident, 7.0 [6.0-8.0]; senior author, 7.0 [6.0-8.0]; chatbot 1, 7.0 [6.0-8.0]; chatbot 2, 7.0 [6.0-8.0]; P = .61), 20-point scores (resident, 14.0 [12.0-7.0]; senior author, 15.0 [13.0-17.0]; chatbot 1, 14.0 [12.0-16.0]; chatbot 2, 14.0 [13.0-16.0]; P = .50), or rank (resident, 3.0 [1.0-4.0]; senior author, 2.0 [1.0-4.0]; chatbot 1, 3.0 [2.0-4.0]; chatbot 2, 2.0 [1.0-3.0]; P = .14). The abstract grades given by chatbot 1 were comparable to the surgeon-reviewers' grades. However, chatbot 2 graded more favorably than the surgeon-reviewers and chatbot 1. Median (IQR) chatbot 2-reviewer grades were higher than surgeon-reviewer grades of all 4 abstract versions (resident, 14.0 [12.0-17.0] vs 16.9 [16.0-17.5]; P = .02; senior author, 15.0 [13.0-17.0] vs 17.0 [16.5-18.0]; P = .03; chatbot 1, 14.0 [12.0-16.0] vs 17.8 [17.5-18.5]; P = .002; chatbot 2, 14.0 [13.0-16.0] vs 16.8 [14.5-18.0]; P = .04). When comparing the grades of the 2 chatbots, chatbot 2 gave higher median (IQR) grades for abstracts than chatbot 1 (resident, 14.0 [13.0-15.0] vs 16.9 [16.0-17.5]; P = .003; senior author, 13.5 [13.0-15.5] vs 17.0 [16.5-18.0]; P = .004; chatbot 1, 14.5 [13.0-15.0] vs 17.8 [17.5-18.5]; P = .003; chatbot 2, 14.0 [13.0-15.0] vs 16.8 [14.5-18.0]; P = .01). Conclusions and Relevance: In this cross-sectional study, trained chatbots generated convincing medical abstracts, undifferentiable from resident or senior author drafts. Chatbot 1 graded abstracts similarly to surgeon-reviewers, while chatbot 2 was less stringent. These findings may assist surgeon-scientists in successfully implementing AI in medical research.</p
Bucindolol: A Pharmacogenomic Perspective on Its Use in Chronic Heart Failure
No full textBucindolol is a non-selective ߭adrenergic receptor blocker with a-1 blocker properties and mild intrinsic sympatholytic activity. The Beta-Blocker Evaluation of Survival Trial (BEST), which is the largest clinical trial of bucindolol in patients with heart failure, was terminated prematurely and failed to show an overall mortality benefit. However, benefits on cardiac mortality and re- hospitalization rates were observed in the BEST trial. Bucindolol has not shown benefits in African Americans, those with significantly low ejection fraction and those in NYHA class IV heart failure. These observations could be due to the exaggerated sympatholytic response to bucindolol in these sub-groups that may be mediated by genetic polymorphisms or changes in gene regulation.Full Tex
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