-
Journal of the American College of... Aug 2017To determine, using systematic review of the biomedical literature, whether pacing reduces risk of recurrent syncope and relevant clinical outcomes among adult patients... (Review)
Review
Pacing as a Treatment for Reflex-Mediated (Vasovagal, Situational, or Carotid Sinus Hypersensitivity) Syncope: A Systematic Review for the 2017 ACC/AHA/HRS Guideline for the Evaluation and Management of Patients With Syncope: A Report of the American College of Cardiology/American Heart Association...
OBJECTIVES
To determine, using systematic review of the biomedical literature, whether pacing reduces risk of recurrent syncope and relevant clinical outcomes among adult patients with reflex-mediated syncope.
METHODS
MEDLINE (through PubMed), EMBASE, and the Cochrane Central Register of Controlled Trials (through October 7, 2015) were searched for randomized trials and observational studies examining pacing and syncope, and the bibliographies of known systematic reviews were also examined. Studies were rejected for poor-quality study methods and for the lack of the population, intervention, comparator, or outcome(s) of interest.
RESULTS
Of 3,188 citations reviewed, 10 studies met the inclusion criteria for systematic review, including a total of 676 patients. These included 9 randomized trials and 1 observational study. Of the 10 studies, 4 addressed patients with carotid sinus hypersensitivity, and the remaining 6 addressed vasovagal syncope. Among the 6 open-label (unblinded) studies, we found that pacing was associated with a 70% reduction in recurrent syncope (relative risk [RR]: 0.30; 95% confidence interval [CI]: 0.15-0.60). When the 2 analyzable studies with double-blinded methodology were considered separately, there was no clear benefit (RR: 0.73; 95% CI: 0.25-2.1), but confidence intervals were wide. The strongest evidence was from the randomized, double-blinded ISSUE-3 (Third International Study on Syncope of Uncertain Etiology) trial, which demonstrated a benefit of pacing among patients with recurrent syncope and asystole documented by implantable loop recorder.
CONCLUSIONS
There are limited data with substantive evidence of outcome ascertainment bias, and only 2 studies with a double-blinded study design have been conducted. The evidence does not support the use of pacing for reflex-mediated syncope beyond patients with recurrent vasovagal syncope and asystole documented by implantable loop recorder.
Topics: Advisory Committees; American Heart Association; Biomedical Research; Cardiac Pacing, Artificial; Cardiology; Disease Management; Humans; Practice Guidelines as Topic; Societies, Medical; Syncope; United States
PubMed: 28286220
DOI: 10.1016/j.jacc.2017.03.004 -
The Cochrane Database of Systematic... May 2021Orthostatic hypotension is an excessive fall in blood pressure (BP) while standing and is the result of a decrease in cardiac output or defective or inadequate...
BACKGROUND
Orthostatic hypotension is an excessive fall in blood pressure (BP) while standing and is the result of a decrease in cardiac output or defective or inadequate vasoconstrictor mechanisms. Fludrocortisone is a mineralocorticoid that increases blood volume and blood pressure. Fludrocortisone is considered the first- or second-line pharmacological therapy for orthostatic hypotension alongside mechanical and positional measures such as increasing fluid and salt intake and venous compression methods. However, there has been no Cochrane Review of the benefits and harms of this drug for this condition.
OBJECTIVES
To identify and evaluate the benefits and harms of fludrocortisone for orthostatic hypotension.
SEARCH METHODS
We searched the following databases on 11 November 2019: Cochrane Neuromuscular Specialised Register, CENTRAL, MEDLINE, Embase and CINAHL. We also searched trials registries.
SELECTION CRITERIA
We included all studies evaluating the benefits and harms of fludrocortisone compared to placebo, another drug for orthostatic hypotension, or studies without comparators, including randomized controlled trials (RCTs), quasi-RCTs and observational studies. We included studies in people with orthostatic hypotension due to a chronic peripheral neuropathy, a central autonomic neuropathy, or autonomic failure from other causes, but not medication-induced orthostatic hypotension or orthostatic hypotension from acute volume depletion or blood loss.
DATA COLLECTION AND ANALYSIS
We used Cochrane methodological procedures for most of the review. We developed and used a tool to prioritize observational studies that offered the best available evidence where there are gaps in the evidence from RCTs. We assessed the certainty of evidence for fludrocortisone versus placebo using GRADE.
MAIN RESULTS
We included 13 studies of 513 participants, including three cross-over RCTs and 10 observational studies (three cohort studies, six case series and one case-control study). The included RCTs were small (total of 28 participants in RCTs), short term (two to three weeks), only examined fludrocortisone for orthostatic hypotension in people with two conditions (diabetes and Parkinson disease), and had variable risk of bias (two had unclear risk of bias and one had low risk of bias). Heterogeneity in participant populations, comparators and outcome assessment methods prevented meta-analyses of the RCTs. We found very low-certainty evidence about the effects of fludrocortisone versus placebo on drop in BP in people with diabetes (-26 mmHg versus -39 mmHg systolic; -7 mmHg versus -11 mmHg diastolic; 1 cross-over study, 6 participants). For people with Parkinson disease, we found very-low certainty evidence about the effects of fludrocortisone on drop in BP compared to pyridostigmine (-14 mmHg versus -22.1 mmHg diastolic; P = 0.036; 1 cross-over study, 9 participants) and domperidone (no change after treatment in either group; 1 cross-over study, 13 participants). For orthostatic symptoms, we found very low-certainty evidence for fludrocortisone versus placebo in people with diabetes (4 out of 5 analyzed participants had improvements in orthostatic symptoms, 1 cross-over study, 6 participants), for fludrocortisone versus pyridostigmine in people with Parkinson disease (orthostatic symptoms unchanged; 1 cross-over study, 9 participants) or fludrocortisone versus domperidone (improvement to 6 for both interventions on the Composite Autonomic Symptom Scale-Orthostatic Domain (COMPASS-OD); 1 cross-over study, 13 participants). Evidence on adverse events was also very low-certainty in both populations, but indicated side effects were minimal. Observational studies filled some gaps in evidence by examining the effects in larger groups of participants, with more diverse conditions, over longer periods of time. One cohort study (341 people studied retrospectively) found fludrocortisone may not be harmful in the long term for familial dysautonomia. However, it is unclear if this translates to long-term improvements in BP drop or a meaningful improvement in orthostatic symptoms.
AUTHORS' CONCLUSIONS
The evidence is very uncertain about the effects of fludrocortisone on blood pressure, orthostatic symptoms or adverse events in people with orthostatic hypotension and diabetes or Parkinson disease. There is a lack of information on long-term treatment and treatment of orthostatic hypotension in other disease states. There is a need for standardized reporting of outcomes and for standardization of measurements of blood pressure in orthostatic hypotension.
Topics: Bias; Diabetes Mellitus; Domperidone; Dysautonomia, Familial; Fludrocortisone; Humans; Hypotension, Orthostatic; Observational Studies as Topic; Parkinson Disease; Pyridostigmine Bromide; Randomized Controlled Trials as Topic
PubMed: 34000076
DOI: 10.1002/14651858.CD012868.pub2 -
Clinical Autonomic Research : Official... Jun 2022Orthostatic syncope (transient loss of conscious when standing-fainting) is common and negatively impacts quality of life. Many patients with syncope report experiencing... (Review)
Review
BACKGROUND
Orthostatic syncope (transient loss of conscious when standing-fainting) is common and negatively impacts quality of life. Many patients with syncope report experiencing fatigue, sometimes with "brain fog", which may further impact their quality of life, but the incidence and severity of fatigue in patients with syncope remain unclear. In this systematic review, we report evidence on the associations between fatigue and conditions of orthostatic syncope.
METHODS
We performed a comprehensive literature search of four academic databases to identify articles that evaluated the association between orthostatic syncope [postural orthostatic tachycardia syndrome (POTS), vasovagal syncope (VVS), orthostatic hypotension (OH)] and fatigue. Studies were independently screened using a multi-stage approach by two researchers to maintain consistency and limit bias.
RESULTS
Our initial search identified 2797 articles, of which 13 met our inclusion criteria (POTS n = 10; VVS n = 1; OH n = 1; VVS and POTS n = 1). Fatigue scores were significantly higher in patients with orthostatic syncope than healthy controls, and were particularly severe in those with POTS. Fatigue associated with orthostatic syncope disorders spanned multiple domains, with each dimension contributing equally to increased fatigue. "Brain fog" was an important symptom of POTS, negatively affecting productivity and cognition. Finally, fatigue was negatively associated with mental health in patients with POTS.
CONCLUSION
In conditions of orthostatic syncope, fatigue is prevalent and debilitating, especially in patients with POTS. The consideration of fatigue in patients with orthostatic disorders is essential to improve diagnosis and management of symptoms, thus improving quality of life for affected individuals.
Topics: Fatigue; Humans; Hypotension, Orthostatic; Postural Orthostatic Tachycardia Syndrome; Quality of Life; Syncope; Syncope, Vasovagal; Tilt-Table Test
PubMed: 35689118
DOI: 10.1007/s10286-022-00868-z -
JACC. Clinical Electrophysiology Apr 2017The aims of this study were to quantify the degree of improvement in vasovagal syncope after assessment and to identify predictive factors. (Meta-Analysis)
Meta-Analysis
OBJECTIVES
The aims of this study were to quantify the degree of improvement in vasovagal syncope after assessment and to identify predictive factors.
BACKGROUND
No treatments for vasovagal syncope have been proved effective, but patients in all prospective studies appear to show a reduction in the likelihood of fainting.
METHODS
A systematic review and meta-analysis was performed of studies published from 1993 through 2013. Inclusion criteria were: 1) vasovagal syncope frequency in the preceding 1 to 2 years; and 2) the proportion of subjects with syncope in at least the first follow-up year. Random-effects methods were used.
RESULTS
Of 338 screened studies, 17 were analyzed, with a mean of 112 subjects (range 9 to 511 subjects). In the preceding epoch, 97% of subjects fainted, with 2.6 ± 1.0 syncopal spells per year. In the follow-up year, the proportion of patients with ≥1 syncope recurrence was 677 of 1,912 (35.4%), and in the meta-analysis, the proportion of subjects fainting was only 0.44 (95% confidence interval: 0.41 to 0.46; p < 0.001). Subjects in larger studies were less likely to faint than those in randomized trials (relative risk: 0.35 vs. 0.55; p = 0.004). The probabilities of ≥1 syncope recurrence in the observational versus randomized studies were 0.30 (95% confidence interval: 0.24 to 0.37) and 0.54 (95% confidence interval: 0.46 to 0.62), respectively (p < 0.001). None of the degree of blinding, type of intervention, age, sex, and number of recent faints predicted the probability of syncope recurrence. Heterogeneity was very high in all analyses (I = 60% to 96%).
CONCLUSIONS
The spontaneous remission rate in highly symptomatic syncope patients is high, and remission occurs in all types of studies. Improvement was more likely in larger and observational studies.
Topics: Adult; Aged; Female; Humans; Male; Middle Aged; Observational Studies as Topic; Randomized Controlled Trials as Topic; Remission, Spontaneous; Syncope, Vasovagal
PubMed: 29759452
DOI: 10.1016/j.jacep.2016.10.012 -
Heart Rhythm Jul 2020Vasovagal syncope (VVS) significantly reduces quality of life, yet lacks effective medical therapies. Pharmacological norepinephrine transporter (NET) inhibition... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Vasovagal syncope (VVS) significantly reduces quality of life, yet lacks effective medical therapies. Pharmacological norepinephrine transporter (NET) inhibition increases synaptic norepinephrine reuptake, which may be able to prevent hypotension, bradycardia, and syncope.
OBJECTIVE
The objective of this systematic review was to evaluate the ability of 3 NET inhibitors-reboxetine, sibutramine, and atomoxetine-to prevent head-up tilt-induced vasovagal outcomes in healthy participants and patients with VVS.
METHODS
Relevant studies were identified from Medical Literature Analysis and Retrieval System Online, Excerpta Medica Database, Cochrane Central Register of Controlled Trials, and Cumulative Index to Nursing and Allied Health Literature without language restriction from database inception to August 2019. All randomized controlled trials comparing the benefit of a NET inhibitor vs placebo in adult populations were selected for review and meta-analysis.
RESULTS
Four studies (101 participants) met inclusion criteria. The mean study size was 25 (range 11-56) participants. NET inhibition reduced the likelihood of vasovagal reactions marked by hypotension and bradycardia in healthy participants during head-up tilt testing (relative risk 0.15; 95% confidence interval 0.04-0.52; P = .003). This relative risk reduction also occurred in patients with VVS during head-up tilt when given atomoxetine (relative risk 0.49; 95% confidence interval 0.28-0.86; P = .01). This was achieved through heart rate compensation with NET inhibition toward the end of tilt testing (106 ± 32 beats/min vs 60 ± 22 beats/min; P < .001), which in turn preserved cardiac output and mean arterial pressure (71 ± 20 mm Hg vs 43 ± 13 mm Hg; P < .001) in the absence of significantly increased systemic vascular resistance.
CONCLUSION
NET inhibition prevents severe vasovagal reactions and syncope induced by head-up tilt testing in both healthy participants and patients with VVS. Pharmacological NET inhibition is a promising potential treatment of recurrent syncope.
Topics: Adult; Cardiac Output; Heart Rate; Humans; Norepinephrine Plasma Membrane Transport Proteins; Quality of Life; Reboxetine; Syncope, Vasovagal; Young Adult
PubMed: 32151742
DOI: 10.1016/j.hrthm.2020.02.033 -
Journal of Arrhythmia Oct 2018Vasovagal syncope (VVS) is defined by transient loss of consciousness with spontaneous rapid recovery. Recently, a closed-loop stimulation pacing system (CLS) has shown...
BACKGROUND
Vasovagal syncope (VVS) is defined by transient loss of consciousness with spontaneous rapid recovery. Recently, a closed-loop stimulation pacing system (CLS) has shown superior effectiveness to conventional pacing in refractory VVS. However, systematic review and meta-analysis has not been performed. We assessed the impact of CLS implantation and reduction in recurrent VVS events by a systematic review and a meta-analysis.
METHODS
We comprehensively searched the databases of MEDLINE and EMBASE from inception to September 2017. Included studies were published prospective or retrospective cohort, randomized controlled trial, and case-control studies that compared VVS events between recurrent, severe, or refractory cardioinhibitory VVS patient implanted with CLS and conventional pacing. Data from each study were combined using the random-effects, generic inverse variance method of DerSimonian and Laird to calculate odds ratios and 95% confidence intervals.
RESULTS
Six studies from November 2004 to October 2017 were included in this meta-analysis involving 224 recurrent, severe, or refractory cardioinhibitory VVS patients implanted with CLS and 163 recurrent, severe, or refractory VVS patients implanted with conventional pacing. CLS significantly reduced recurrent VVS events compared to conventional pacing (pooled odds ratio = 0.23, 95% confidence interval: 0.13-0.39, = 0.000, = 36.5%) as well as subgroup of four randomized controlled trial studies (pooled odds ratio = 0.28, 95% confidence interval: 0.17-0.44, = 0.000, = 39.2%).
CONCLUSION
Closed-loop stimulation significantly reduced recurrent VVS events up to 80% when compared to conventional pacing. Our study suggests that CLS is an effective tool for preventing syncope recurrences in patients with recurrent, severe, or refractory cardioinhibitory VVS.
PubMed: 30327702
DOI: 10.1002/joa3.12102 -
Frontiers in Cardiovascular Medicine 2022Physical counter pressure maneuvers (CPM) are movements that are recommended to delay or prevent syncope (fainting) by recruiting the skeletal muscle pump to augment... (Review)
Review
Physical counter pressure maneuvers (CPM) are movements that are recommended to delay or prevent syncope (fainting) by recruiting the skeletal muscle pump to augment cardiovascular control. However, these recommendations are largely based on theoretical benefit, with limited data evaluating the efficacy of CPM to prevent syncope in the real-world setting. We conducted a semi-systematic literature review and meta-analysis to assess CPM efficacy, identify literature gaps, and highlight future research needs. Articles were identified through a literature search (PubMed, April 2022) of peer-reviewed publications evaluating the use of counter pressure or other lower body maneuvers to prevent syncope. Two team members independently screened records for inclusion and extracted data. From 476 unique records identified by the search, 45 met inclusion criteria. Articles considered various syncopal conditions (vasovagal = 12, orthostatic hypotension = 8, postural orthostatic tachycardia syndrome = 1, familial dysautonomia = 2, spinal cord injury = 1, blood donation = 10, healthy controls = 11). Maneuvers assessed included hand gripping, leg fidgeting, stepping, tiptoeing, marching, calf raises, postural sway, tensing (upper, lower, whole body), leg crossing, squatting, "crash" position, and bending foreword. CPM were assessed in laboratory-based studies ( = 28), the community setting ( = 4), both laboratory and community settings ( = 3), and during blood donation ( = 10). CPM improved standing systolic blood pressure (+ 14.8 ± 0.6 mmHg, < 0.001) and heart rate (+ 1.4 ± 0.5 bpm, = 0.006), however, responses of total peripheral resistance, stroke volume, or cerebral blood flow were not widely documented. Most patients experienced symptom improvement following CPM use (laboratory: 60 ± 4%, community: 72 ± 9%). The most prominent barrier to employing CPM in daily living was the inability to recognize an impending faint. Patterns of postural sway may also recruit the skeletal muscle pump to enhance cardiovascular control, and its potential as a discrete, proactive CPM needs further evaluation. Physical CPM were successful in improving syncopal symptoms and producing cardiovascular responses that may bolster against syncope; however, practical limitations may restrict applicability for use in daily living.
PubMed: 36312294
DOI: 10.3389/fcvm.2022.1016420 -
Frontiers in Cardiovascular Medicine 2022Syncope (transient loss of consciousness and postural tone) and presyncope are common manifestations of autonomic dysfunction that are usually triggered by orthostasis....
PURPOSE
Syncope (transient loss of consciousness and postural tone) and presyncope are common manifestations of autonomic dysfunction that are usually triggered by orthostasis. The global impact of syncope on quality of life (QoL) is unclear. In this systematic review, we report evidence on the impact of syncope and presyncope on QoL and QoL domains, identify key factors influencing QoL in patients with syncopal disorders, and combine available data to compare QoL between syncopal disorders and to population normative data.
METHODS
A comprehensive literature search of academic databases (MEDLINE (PubMed), Web of Science, CINAHL, PsycINFO, and Embase) was conducted (February 2021) to identify peer-reviewed publications that evaluated the impact of vasovagal syncope (VVS), postural orthostatic tachycardia syndrome (POTS), or orthostatic hypotension (OH) on QoL. Two team members independently screened records for inclusion and extracted data relevant to the study objectives.
RESULTS
From 12,258 unique records identified by the search, 36 studies met the inclusion criteria (VVS: = 20; POTS: = 13; VVS and POTS: = 1; OH: = 2); 12 distinct QoL instruments were used. Comparisons of QoL scores between patients with syncope/presyncope and a control group were performed in 16 studies; significant QoL impairments in patients with syncope/presyncope were observed in all studies. Increased syncopal event frequency, increased autonomic symptom severity, and the presence of mental health disorders and/or comorbidities were associated with lower QoL scores.
CONCLUSION
This review synthesizes the negative impact of syncope/presyncope on QoL and identifies research priorities to reduce the burden of these debilitating disorders and improve patient QoL.
PubMed: 35224062
DOI: 10.3389/fcvm.2022.834879 -
Diagnostics (Basel, Switzerland) Nov 2023The objective of this study was to compare the outcomes of the ultrasound- and fluoroscopy-guided techniques in the management of back pain. Using PubMed, Scopus, and... (Review)
Review
The objective of this study was to compare the outcomes of the ultrasound- and fluoroscopy-guided techniques in the management of back pain. Using PubMed, Scopus, and the Cochrane Library, we searched randomized controlled trials (RCTs) published before May 2023, which reported relevant data on the topic. The effectiveness of the ultrasound-guided (US-guided) and fluoroscopy-guided (FL-guided) approaches for back pain management was compared in terms of postoperative pain intensity, postoperative functional outcomes, and postoperative complications. Subgroup analyses were conducted for different postoperative periods. Eight studies were included in the analysis. There was no significant difference in post-procedural pain relief at one week, two weeks, one month, two months, and three months between the US-guided and FL-guided interventions for back pain management (SMD with 95% CI is -0.01 [-0.11, 0.10]), = 0.91, I = 0%). In terms of the postoperative functional outcomes assessed by the "Oswestry Disability Index" (ODI) functionality score, the model tends to favor the FL-guided injections over the US-guided injections (SMD with 95% CI: 0.13 [-0.00, 0.25], = 0.05, I = 0). Finally, the US-guided and FL-guided injections did not show significantly different results in terms of postoperative complications (RR with 95% CI is 0.99 [0.49, 1.99], = 0.97, I = 0). The subgroup analysis also did not demonstrate differences between the US-guided and FL-guided techniques in the following outcomes: vasovagal reaction, transient headache, and facial flushing. There was no significant difference between the US-guided and FL-guided injections for treating back pain in terms of postoperative pain intensity and complications. Still, the model tends to favor the FL-guided injections over the US-guided injections in terms of functionality.
PubMed: 37998610
DOI: 10.3390/diagnostics13223474 -
PloS One 2019To summarize the best available evidence on the effectiveness of physical counterpressure manoeuvers (PCM) for vasovagal syncope management compared to a control... (Meta-Analysis)
Meta-Analysis
AIMS
To summarize the best available evidence on the effectiveness of physical counterpressure manoeuvers (PCM) for vasovagal syncope management compared to a control intervention. Control interventions included either a PCM, no intervention, or other interventions feasible in a lay setting.
METHODS
A systematic literature search (March 21st 2018) was performed in the Cochrane Central Register of Controlled Trials, MEDLINE, and Embase. PCM were subdivided into 1) PCM decreasing orthostatic load (PCMOL), 2) PCM shortening the hydrostatic column between heart and brain (PCMHC), 3) PCM using mechanical compression of the veins (PCMMC). The primary outcome was syncope, secondary outcomes included systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP), heart rate (HR), stroke volume (SV), cardiac output (CO), and total peripheral resistance (TPR). When possible, a random effects meta-analysis was performed. Odds ratios (OR) with 95% confidence intervals (CI) were calculated for dichotomous outcomes, and mean differences (MD) or standardized mean differences (SMD) were calculated for continuous outcomes. Heterogeneity was assessed by means of the I2 statistic. The total body of evidence was evaluated by means of the GRADE methodology.
RESULTS
Eleven trials involving 688 people with vasovagal syncope were included. Risk of bias was high in all included studies. The total body of evidence (GRADE) was considered to be low or very low. PCM were found to improve syncope as compared to control (OR: 0.52, 95% CI [0.33;0.81], p = 0.004). Similarly, before-and-after studies without a control group showed a significant reduction in syncope following PCM (OR: 0.01, 95%CI [0.00;0.01], p<0.001). No studies investigated PCMOL. PCMHC increased SBP, DBP, MAP, SV, and CO, and decreased HR. PCMMC increased SBP, DBP, and MAP.
CONCLUSION
PCM may reduce syncope and increase SBP, DBP, and MAP. The effects on other outcomes are less clear. Additional high-quality studies are needed.
Topics: Bias; Blood Pressure; Female; Humans; Male; Motor Activity; Non-Randomized Controlled Trials as Topic; Randomized Controlled Trials as Topic; Syncope, Vasovagal; Treatment Outcome
PubMed: 30818337
DOI: 10.1371/journal.pone.0212012