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ESC Heart Failure Feb 2020To retrieve and assess the available data in the literature about the safety and efficacy of baroreflex activation therapy (BAT) in heart failure with reduced ejection... (Review)
Review
To retrieve and assess the available data in the literature about the safety and efficacy of baroreflex activation therapy (BAT) in heart failure with reduced ejection fraction (HFrEF) patients, through a rapid systematic review of clinical studies. Rapid systematic review of literature. Searched electronic databases included PubMed, EMBASE, CENTRAL, Scopus, and Web of Science using Mesh and free terms for heart failure and BAT. No language restriction was used for the searches. We included full peer reviewed publications of clinical studies (randomized or not), including patients with HFrEF undergoing BAT, with or without control group, assessing safety and efficacy outcomes. One reviewer conducted the analysis of the selected abstracts and the full-text articles, performed data extraction, and evaluated the methodological quality of the selected articles. The methodological quality was assessed according to the Cochrane Collaboration instruments. A descriptive summary of the results is provided. Of the 441 citations screened, 10 publications were included (three were only conference abstracts), reporting data from three studies. Only one study was a randomized clinical trial. Two studies reported a 6 month following, and the other study analysed outcomes up to 41 months. The procedure seems to be safe when performed by a well-trained multi-professional team. An 86% rate of system and procedure-related complication-free was reported, with no cranial nerve injuries. Improvements in New York Heart Association class of heart failure, quality of life, 6 min walk test, and hospitalization rates, as well as in muscle sympathetic nerve activity. No meta-analysis was conducted because of the lack of homogeneity across studies; the results from each study are reported individually. BAT procedure seems to be safe if appropriate training is provided. Improvements in clinical outcomes were described in all included studies. However, several limitations do not allow us to make conclusive statements on the efficacy of BAT for HFrEF. New well-designed trials are still needed.
Topics: Baroreflex; Electric Stimulation Therapy; Heart Failure; Humans; Quality of Life; Randomized Controlled Trials as Topic; Stroke Volume
PubMed: 31965746
DOI: 10.1002/ehf2.12543 -
ESC Heart Failure Oct 2023Baroreflex activation therapy (BAT) is a possible adjuvant treatment for patients with heart failure with reduced ejection fraction (HFrEF) who remain symptomatic... (Review)
Review
Baroreflex activation therapy (BAT) is a possible adjuvant treatment for patients with heart failure with reduced ejection fraction (HFrEF) who remain symptomatic despite optimal medical therapy and may be an alternative therapy in patients with contraindications or drug intolerance. Our aim was to evaluate the efficacy and safety of BAT in patients with HFrEF. The protocol for this study was registered with PROSPERO (CRD42022349175). Searches were conducted using MEDLINE, preMedLine (via PubMed), EMBASE, Cochrane Library, Web of Science, Trip Medical Database, WHO International Clinical Trials Registry, and ClinicalTrials.gov. We included randomized controlled trials that compared the effects of BAT with pharmacological treatment. We assessed the risk of bias of each study using the Cochrane RoB2 tool and the certainty of the results using the GRADE approach. We performed a meta-analysis of treatment effects using a fixed-effects or random-effects model, depending on the heterogeneity observed. Two studies were included in the meta-analysis (HOPE4HF and BeAT-HF). The results showed that BAT led to statistically significant improvements in New York Heart Association functional class (relative risk 2.13; 95% confidence interval [CI, 1.65 to 2.76]), quality of life (difference in means -16.97; 95% CI [-21.87 to -12.07]), 6 min walk test (difference in means 56.54; 95% CI [55.67 to 57.41]) and N-terminal probrain natriuretic peptide (difference in means -120.02; 95% CI [-193.58 to -46.45]). The system- and procedure-related complication event-free rate varied from 85.9% to 97%. The results show that BAT is safe and improves functional class, quality of life and congestion in selected patients with HFrEF. Further studies and long-term follow-up are needed to assess efficacy in reducing cardiovascular events and mortality.
PubMed: 37522644
DOI: 10.1002/ehf2.14473 -
Frontiers in Neuroscience 2023The number of randomized controlled trials using auricular stimulation (AS) such as transauricular vagus nerve stimulation, or other auricular electrostimulation or...
BACKGROUND
The number of randomized controlled trials using auricular stimulation (AS) such as transauricular vagus nerve stimulation, or other auricular electrostimulation or auricular acupuncture or acupressure, in experimental and clinical settings, has increased markedly over the last three decades. This systematic review focusses on cardiovascular effects of auricular stimulation.
METHODS AND ANALYSIS
The following databases were searched: MEDLINE (PubMed), EMBASE, Cochrane Central Register of Controlled Trials (CENTRAL), ISI Web of Science, and Scopus Database. RCTs were reviewed that had been published in English and European languages. Data collection and analysis was conducted by two reviewers independently. Quality and risk assessment of included studies was performed and the meta-analysis of the effect of the most frequently assessed biomarkers.
RESULTS
Altogether, 78 trials were included. 38 studies assessed heart rate (HR), 19 studies analyzed heart rate variability (HRV), 31 studies analyzed blood pressure (BP) and 7 studies were identified that measured oxygen saturation (O2), 2 studies on baroreflex sensitivity and 2 studies on skin conductance were evaluated in this review. 26 studies contained continuous data and were eligible for meta-analysis, 50 trials reported non continuous data and were evaluated descriptively. The overall quality of the studies was moderate to low. AS leads to a significant reduction of HR, the changes though were not considered an adverse reaction. Furthermore, when looking at HRV, AS was able to reduce the LF/HF ratio significantly compared to control procedures. No other cardiovascular parameters (blood pressure, oxygen saturation, baroreflex sensitivity) were changed significantly. AS produced only minor side effects in all trials.
CONCLUSION
AS can lead to clinically safe reduction of HR and changes in the LF/HF ratio of the HRV, which is presumably via an increase in vagal activity. More research is needed to clarify whether AS can be used to modulate tachycardia or indications with autonomic imbalance.
SYSTEMATIC REVIEW REGISTRATION
https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=231885 PROSPERO, ID CRD42021231885.
PubMed: 37727325
DOI: 10.3389/fnins.2023.1227858 -
Applied Psychophysiology and Biofeedback Sep 2023Heart Rate Variability Biofeedback (HRVB) has been widely used to improve cardiovascular health and well-being. HRVB is based on breathing at an individual's resonance... (Review)
Review
Heart Rate Variability Biofeedback (HRVB) has been widely used to improve cardiovascular health and well-being. HRVB is based on breathing at an individual's resonance frequency, which stimulates respiratory sinus arrhythmia (RSA) and the baroreflex. There is, however, no methodological consensus on how to apply HRVB, while details about the protocol used are often not well reported. Thus, the objectives of this systematic review are to describe the different HRVB protocols and detect methodological concerns. PsycINFO, CINALH, Medline and Web of Science were searched between 2000 and April 2021. Data extraction and quality assessment were based on PRISMA guidelines. A total of 143 studies were finally included from any scientific field and any type of sample. Three protocols for HRVB were found: (i) "Optimal RF" (n = 37), each participant breathes at their previously detected RF; (ii) "Individual RF" (n = 48), each participant follows a biofeedback device that shows the optimal breathing rate based on cardiovascular data in real time, and (iii) "Preset-pace RF" (n = 51), all participants breathe at the same rate rate, usually 6 breaths/minute. In addition, we found several methodological differences for applying HRVB in terms of number of weeks, duration of breathing or combination of laboratory and home sessions. Remarkably, almost 2/3 of the studies did not report enough information to replicate the HRVB protocol in terms of breathing duration, inhalation/exhalation ratio, breathing control or body position. Methodological guidelines and a checklist are proposed to enhance the methodological quality of future HRVB studies and increase the information reported.
Topics: Humans; Heart Rate; Biofeedback, Psychology; Exhalation; Respiratory Rate; Respiratory Sinus Arrhythmia
PubMed: 36917418
DOI: 10.1007/s10484-023-09582-6 -
Healthcare (Basel, Switzerland) Oct 2023Diabetic neuropathy, including autonomic neuropathy, is a severe complication in patients with poorly controlled diabetes. Specifically, cardiovascular autonomic... (Review)
Review
BACKGROUND
Diabetic neuropathy, including autonomic neuropathy, is a severe complication in patients with poorly controlled diabetes. Specifically, cardiovascular autonomic neuropathy (CAN) plays a significant prognostic role in cardiovascular morbidity and mortality. Exercise, an essential component of diabetes treatment, may have a therapeutic effect on patients with diabetes complicated by CAN. However, it remains unclear whether exercise has a therapeutic or protective effect in diabetes patients with CAN.
METHODS
The author conducted a systematic search of PubMed/MEDLINE, Embase, and The Cochrane Library, resulting in the identification of eight eligible randomized controlled trials for this review.
RESULTS
Exercise, including aerobic exercise combined with resistance training (RT), high-intensity interval training, and progressive RT, has shown a beneficial effect on cardiac autonomic function (CAF) in patients with type 2 diabetes, as measured by heart rate variability, heart rate recovery, and baroreflex sensitivity. However, most studies had low quality. Moreover, there were no relevant studies examining the effect of exercise on CAF in older patients, patients with poorly controlled diabetes, and patients with type 1 diabetes.
CONCLUSIONS
Exercise has the potential to manage patients with CAN by balancing sympathetic and parasympathetic nervous system functions; however, further studies are warranted in the future.
PubMed: 37830705
DOI: 10.3390/healthcare11192668 -
Frontiers in Physiology 2021Heart rate variability (HRV), the beat-to-beat variation of adjacent heartbeats, is an indicator of the function of the autonomic nervous system (ANS). Increased HRV...
Heart rate variability (HRV), the beat-to-beat variation of adjacent heartbeats, is an indicator of the function of the autonomic nervous system (ANS). Increased HRV reflects well-functioning of autonomic control mechanism and cardiovascular health. The aim of this systematic review is to provide a systematic overview of the effects of different physical training modalities on resting HRV and cardiovascular health and risk factors (i.e., baroreflex sensitivity, body fat, body mass, body mass index, blood pressure, heart rate recovery, VO max, and VO peak) in young and middle-aged (mean age of the studies samples up to 44 years), healthy adults. A systematic review in accordance with the PRISMA guidelines was performed. Studies investigating the effects of different physical interventions (endurance, resistance, high-intensity, coordinative, or multimodal training) on HRV were included. Trials were considered eligible if the intervention lasted for at least 4 weeks and participants were regarded as general healthy. Five electronic databases were searched from 2005 to September 8th, 2020. The methodological quality of eligible studies was assessed by two study quality and reporting assessment scales (TESTEX and STARD). PROSPERO registration number: CRD42020206606. Of 3,991 retrieved records, 26 were considered eligible and analyzed. Twelve studies used an endurance training (of which three included high-intensity sessions), six studies resistance training, four studies coordinative training, two studies high-intensity training, and two studies used a multimodal intervention. Overall, the results showed for all types of intervention an improvement in linear and non-linear HRV parameters and cardiovascular health and risk factors. However, quality assessment revealed some methodological and reporting deficits. This systematic review highlights the benefits of different types of physical training interventions on autonomic function and health parameters in young and middle-aged, healthy adults. In conclusion, higher training intensities and frequencies are more likely to improve HRV. For future studies, we recommend adhering to the criteria of methodological standards of exercise interventions and HRV measurements and encourage the use of non-linear HRV parameters.
PubMed: 33981251
DOI: 10.3389/fphys.2021.657274 -
Neurology International Sep 2023The aim of this systematic review with meta-analysis was to determine differences in cardiovascular autonomic parameters between patients with myasthenia gravis (MG) and... (Review)
Review
The aim of this systematic review with meta-analysis was to determine differences in cardiovascular autonomic parameters between patients with myasthenia gravis (MG) and healthy controls (HCs). Two reviewers searched four electronic databases, namely PubMed, Web of Science, EMBASE, and SCOPUS, from database inception to 7 July 2023 for studies investigating cardiovascular autonomic parameters in MG vs. HCs. A random-effects meta-analysis was performed to compute Hedges' g ± 95% confidence intervals (CI). Out of a total of 2200 records, 8 observational studies with a sample size of 301 patients with MG and 454 HCs were included in the systematic review. Meta-analysis revealed lower values of expiration/inspiration ratio (g = -0.45, I = 74.7), baroreflex sensitivity (g = -0.56, 95%CI -0.80, -0.33; I = 0.3), percentage of adjacent NN intervals differing by more than 50 ms (g = -1.2, I = 82.8), square root of the mean of squared differences between successive beat intervals (g = -1.94, I = 95.1), mean of the standard deviations of all NN intervals (g = -0.83, 95%CI -1.37, -0.28; I = 55.5), and high frequency of HRV during tilt (g = -0.75, 95%CI -0.11, -0.39; I = 0). MG patients vs. HCs had higher systolic blood pressure (g = 0.39; I = 56.1), sympathovagal balance at rest/during tilt (LF/HF-RRI, g = 0.44; I = 0; LF/HF-RRI, g = 0.86; I = 0; LF/HF, g = 0.40; I = 0). As a group, MG patients have altered cardiac autonomic function, including decreased parasympathetic function, lower baroreflex sensitivity, and higher sympathovagal balance at rest and during orthostatic challenges.
PubMed: 37755362
DOI: 10.3390/neurolint15030071 -
Annals of Medicine and Surgery (2012) Mar 2014Greater sympathetic drive has been established in the early stages of essential hypertension, suggesting that neurohormonal dysregulation may be key to its aetiology and... (Review)
Review
INTRODUCTION
Greater sympathetic drive has been established in the early stages of essential hypertension, suggesting that neurohormonal dysregulation may be key to its aetiology and progression. The aims of this review are to discuss evidence of the role of autonomic dysfunction in essential hypertension and proposed mechanisms, and also some applications of this knowledge to current management strategies of essential hypertension.
METHODS
A computer search was performed using the PUBMED database for peer reviewed original articles comparing autonomic function tested via heart rate variability (HRV), muscle sympathetic nerve activity (MSNA) or plasma noradrenaline levels in normotensive (mean blood pressure (BP) of ≤140/90 mmHg or ≤135/85 mmHg if measured via home BP measurements) and hypertensive groups (mean resting BP of ≥140/90 mmHg (or ≥135/85 mmHg if measured via home BP measurements). Subjects were excluded with secondary causes of hypertension or autonomic dysfunction.
RESULTS
A total of 17 studies were included for discussion. The main findings of this study include that of reduced baroreflex sensitivity, believed to be secondary to increased arterial stiffness, is hypothesised to be implicated in the pathogenesis of essential hypertension. Also, angiotensin converting enzyme inhibitors were not as effective on markers of autonomic control of blood pressure when compared with alternative anti-hypertensive drugs.
CONCLUSIONS
Consistent research is needed to establish the effectiveness of pharmacotherapies at each of stage of hypertension, and on markers of autonomic dysfunction. Consistent study designs will enable more accurate accumulation of data across multiple studies, and appropriate application of such data into clinical practice.
PubMed: 25568776
DOI: 10.1016/j.amsu.2013.11.002 -
Neurology Jul 2021To describe the natural history of afferent baroreflex failure (ABF) based on systematic review of clinical and laboratory data in patients with a diagnosis of ABF at...
OBJECTIVE
To describe the natural history of afferent baroreflex failure (ABF) based on systematic review of clinical and laboratory data in patients with a diagnosis of ABF at Mayo Clinic Rochester.
METHODS
We performed a retrospective chart review of all patients who underwent standardized autonomic reflex testing between 2000 and 2020 and had confirmation of the diagnosis of ABF by an autonomic disorders specialist. Patients were identified using a data repository of medical records. Variables included demographic, all-cause mortality, medications, ABF manifestations, comorbidities, and laboratory (autonomic testing, blood pressure monitoring, echocardiogram, brain imaging, plasma catecholamines, serum sodium level, and kidney function tests).
RESULTS
A total of 104 patients with ABF were identified. Head and neck radiation was the most common etiology (86.5%), followed by neck surgery (5.8%) and other causes (7.7%). The most common findings were hypertension (87.5%), fluctuating blood pressure (78.8%), orthostatic hypotension (91.3%), syncope (58.6%), headache (22.1%), and tachycardia (20.2%). Patients commonly received antihypertensives (66.3%), pressor agents (41.3%), or a combination of both (19.2%). The median latency from completion of radiation to ABF was longer compared to the latency in the surgery group ( < 0.0001). Comorbidities, including complications from neck radiation, were frequently seen and all-cause mortality was 39.4% over a 20-year period.
CONCLUSIONS
ABF should be suspected in patients with prior head and neck cancer treated by radiation or surgery who present with labile hypertension and orthostatic hypotension. Management may require both antihypertensive and pressor medications. The morbidity and mortality in ABF are high.
Topics: Afferent Pathways; Autonomic Nervous System Diseases; Baroreflex; Blood Pressure; Blood Pressure Determination; Humans; Hypertension; Retrospective Studies
PubMed: 33947784
DOI: 10.1212/WNL.0000000000012149 -
Frontiers in Physiology 2020The aim of this review is to demonstrate the effects of cardiovascular interval training (IT) on healthy elderly subjects. We used the recommendations of the Preferred...
The aim of this review is to demonstrate the effects of cardiovascular interval training (IT) on healthy elderly subjects. We used the recommendations of the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines. The following variables were observed: resting heart rate (HR), systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MBP), heart rate variability (HRV), baroreflex activity (BA), and maximal oxygen uptake (VO). Studies were searched for in the MedLine, PubMed, and Sport Discus databases considering publications between 1990 and 2019. To find the studies, the keywords used were "Interval and Elderly Training" or "Interval Training and Baroreflex Sensing" or "Interval Training and Aging and Pressure Arterial and Blood Pressure Training" or "Interval Training and Variation in Aging and Heart Rate" or "Interval Training and Sensitivity to the Elderly and Baroreflex" or "Interval Training and Variability in the Elderly and Heart Rate." The systematic search identified 1,140 hits. The analysis of the study was performed through a critical review of the content. One thousand one hundred forty articles were identified. Of these, 1,108 articles were excluded by checking the articles and abstracts. Finally, 32 studies were selected for full reading while 26 studies were eliminated because they did not contain a methodology according to the purpose of this review. Thus, six studies were included for the final analysis. The PEDro score was used for analyzing the study quality and found 4,8 ± 1,3 points (range: 3-6). Positive results were found with the different IT protocols in the observed variables. Results show that IT protocols can be an efficient method for functional improvement of cardiovascular and cardiorespiratory variables in the healthy elderly, especially HR, SBP, DBP, MAP, HRV, BA, and VO. However, this method can be included in the prescription of aerobic training for the elderly to obtain conditional improvements in the cardiovascular system, thus being an important clinical intervention for the public.
PubMed: 32848808
DOI: 10.3389/fphys.2020.00739