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Neurologia (Barcelona, Spain) 2016Neurally-mediated syncope (NMS) is defined as a transient loss of consciousness due to an abrupt and intermittent drop in blood pressure (BP). (Review)
Review
INTRODUCTION
Neurally-mediated syncope (NMS) is defined as a transient loss of consciousness due to an abrupt and intermittent drop in blood pressure (BP).
OBJECTIVES
This study describes the putative pathophysiological mechanisms giving rise to NMS, the role of baroreflex (BR), and the interaction of its main haemodynamic variables: heart rate (HR) and BP.
DEVELOPMENT
Episodic dysregulation affects control over the haemodynamic variables (HR and BP) mediated by baroreflex mechanisms. During active standing, individuals experience a profound transient drop in systolic BP due to the effect of gravity on the column of blood and probably also because of reflex vasodilation. Abnormalities in the BR in NMS could be due to a more profound drop in BP upon standing, or to delayed or incomplete vasoconstriction resulting from inhibited or delayed sympathetic activity.
CONCLUSIONS
Sympathetic hyperactivity is present in patients with NMS at rest and before syncope. During active standing or passive tilting, excessive tachycardia may be followed by bradycardia and profound hypotension. Recovery of systolic BP is delayed or incomplete.
Topics: Autonomic Nervous System; Baroreflex; Blood Pressure; Heart Rate; Humans; Posture; Reflex; Syncope
PubMed: 24844455
DOI: 10.1016/j.nrl.2014.04.001 -
The New England Journal of Medicine Oct 2017
Review
Topics: Carotid Sinus; Dizziness; Humans; Massage; Syncope; Tachycardia, Supraventricular
PubMed: 29020587
DOI: 10.1056/NEJMvcm1313338 -
Annals of Clinical and Translational... Oct 2022Vestibular syncope is a condition in which vertigo-induced hemodynamic changes cause syncope. This study investigated the clinical and laboratory findings of vestibular...
BACKGROUND AND OBJECTIVES
Vestibular syncope is a condition in which vertigo-induced hemodynamic changes cause syncope. This study investigated the clinical and laboratory findings of vestibular syncope and tried to refine our knowledge of the mechanism underlying this newly recognized entity.
METHODS
This study retrospectively analyzed 53 patients (33 women, median age = 63 years [interquartile range = 54-71 years]) with vestibular syncope from January 2017 to December 2021. To explain the mechanism of vestibular syncope, we incorporated a velocity-storage model into the dual reflex pathways comprising the vestibulo-sympathetic reflex and baroreflex and predicted the cardiovascular responses.
RESULTS
Twenty (37.7%) patients had multiple episodes of vestibular syncope, and seven (13.2%) had potentially life-threatening injuries. Meniere's disease (20.8%) and benign paroxysmal positional vertigo (9.4%) were the most common underlying vestibular disorders. Abnormal vestibular function tests included impaired cervical vestibular-evoked myogenic potentials (57.5%) and positive head impulse tests (31.0%). Orthostatic hypotension was found in 19.5% of patients. Dyslipidemia (30.2%) and hypertension (28.3%) were common medical comorbidities. The dual reflex pathways incorporating the function of the velocity-storage circuit in the brainstem and cerebellum suggest that vestibular syncope is a neurally mediated reflex syncope associated with a sudden hemodynamic change during vertigo. This change can be arterial hypertension triggered by a false downward inertial cue, as suggested previously, or hypotension driven by a false upward inertial cue.
CONCLUSIONS
Vestibular syncope is associated with various vestibular disorders and requires careful evaluation and intervention to prevent recurrent falls and significant injuries.
Topics: Aged; Female; Humans; Hypertension; Meniere Disease; Middle Aged; Retrospective Studies; Syncope; Vertigo
PubMed: 36056529
DOI: 10.1002/acn3.51661 -
Current Cardiology Reviews 2022Syncope is a common clinical presentation defined as a transient loss of consciousness (TLOC) due to cerebral hypoperfusion, characterized by a rapid onset, short... (Review)
Review
Syncope is a common clinical presentation defined as a transient loss of consciousness (TLOC) due to cerebral hypoperfusion, characterized by a rapid onset, short duration, and spontaneous complete recovery. Different clinical decision rules (CDRs) and risk stratification scores have been developed to predict short- and long-term risks for adverse outcomes after syncope. The central theme of these prediction systems is consistent with the ESC syncope guidelines. Initial assessment according to the ESC guideline is essential until an optimal and well-validated risk score is available. The focus should be accurate risk stratification to allow prevention of adverse outcomes and optimize the use of limited healthcare resources. In this review article, we summarize and critically appraise the evidence regarding the CDRs for patients presenting with syncope.
Topics: Emergency Service, Hospital; Humans; Risk Factors; Syncope
PubMed: 35319380
DOI: 10.2174/1573403X18666220321104129 -
International Journal of Environmental... Nov 2021Syncope and presyncope episodes that occur during work could affect one's safety and impair occupational performance. Few data are available regarding the prevalence of...
Syncope and presyncope episodes that occur during work could affect one's safety and impair occupational performance. Few data are available regarding the prevalence of these events among workers. The possible role of sleep quality, mental stress, and metabolic disorders in promoting syncope, presyncope, and falls in workers is unknown. In the present study, 741 workers (male 35.4%; mean age 47 ± 11 years), employed at different companies, underwent clinical evaluation and blood tests, and completed questionnaires to assess sleep quality, occupational distress, and mental disorders. The occurrence of syncope, presyncope, and unexplained falls during working life was assessed via an ad hoc interview. The prevalence of syncope, presyncope, and falls of unknown origin was 13.9%, 27.0%, and 10.3%, respectively. The occurrence of syncope was associated with an increased risk of occupational distress (adjusted odds ratio aOR: 1.62, confidence intervals at 95%: 1.05-2.52), low sleep quality (aOR: 1.79 CI 95%: 1.16-2.77), and poor mental health (aOR: 2.43 CI 95%: 1.52-3.87). Presyncope was strongly associated with occupational distress (aOR: 1.77 CI 95%: 1.25-2.49), low sleep quality (aOR: 2.95 CI 95%: 2.08-4.18), and poor mental health (aOR: 2.61 CI 95%: 1.78-3.84), while no significant relationship was found between syncope or presyncope and metabolic syndrome. These results suggest that occupational health promotion interventions aimed at improving sleep quality, reducing stressors, and increasing worker resilience might reduce syncope and presyncope events in the working population.
Topics: Adult; Humans; Male; Middle Aged; Occupational Health; Odds Ratio; Prevalence; Sleep Quality; Syncope
PubMed: 34886008
DOI: 10.3390/ijerph182312283 -
Annals of Emergency Medicine Dec 2014There is limited evidence to guide the emergency department (ED) evaluation and management of syncope. The First International Workshop on Syncope Risk Stratification in...
STUDY OBJECTIVES
There is limited evidence to guide the emergency department (ED) evaluation and management of syncope. The First International Workshop on Syncope Risk Stratification in the Emergency Department identified key research questions and methodological standards essential to advancing the science of ED-based syncope research.
METHODS
We recruited a multinational panel of syncope experts. A preconference survey identified research priorities, which were refined during and after the conference through an iterative review process.
RESULTS
There were 31 participants from 7 countries who represented 10 clinical and methodological specialties. High-priority research recommendations were organized around a conceptual model of ED decisionmaking for syncope, and they address definition, cohort selection, risk stratification, and management.
CONCLUSION
We convened a multispecialty group of syncope experts to identify the most pressing knowledge gaps and defined a high-priority research agenda to improve the care of patients with syncope in the ED.
Topics: Biomedical Research; Emergency Medical Services; Humans; Syncope
PubMed: 24882667
DOI: 10.1016/j.annemergmed.2014.04.014 -
World Neurosurgery May 2021The proclivity to atlantoaxial instability (AAI) has been widely reported for conditions such as rheumatoid arthritis and Down syndrome. Similarly, we have found a...
BACKGROUND
The proclivity to atlantoaxial instability (AAI) has been widely reported for conditions such as rheumatoid arthritis and Down syndrome. Similarly, we have found a higher than expected incidence of AAI in hereditary connective tissue disorders. We demonstrate a strong association of AAI with manifestations of dysautonomia, in particular syncope and lightheadedness, and make preliminary observations as to the salutary effect of surgical stabilization of the atlantoaxial motion segment.
METHODS
In an institutional review board-approved retrospective study, 20 subjects (16 women, 4 men) with hereditary connective tissue disorders had AAI diagnosed by computed tomography. Subjects underwent realignment (reduction), stabilization, and fusion of the C1-C2 motion segment. All subjects completed preoperative and postoperative questionnaires in which they were asked about performance, function, and autonomic symptoms, including lightheadedness, presyncope, and syncope.
RESULTS
All patients with AAI reported lightheadedness, and 15 had refractory syncope or presyncope despite maximal medical management and physical therapy. Postoperatively, subjects reported a statistically significant improvement in lightheadedness (P = 0.003), presyncope (P = 0.006), and syncope (P = 0.03), and in the frequency (P < 0.05) of other symptoms related to autonomic function, such as nausea, exercise intolerance, palpitations, tremors, heat intolerance, gastroesophageal reflux, and sleep apnea.
CONCLUSIONS
This study draws attention to the potential for AAI to present with syncope or presyncope that is refractory to medical management, and for surgical stabilization of AAI to lead to improvement of these and other autonomic symptoms.
Topics: Adolescent; Adult; Atlanto-Axial Joint; Female; Humans; Incidence; Joint Instability; Male; Middle Aged; Retrospective Studies; Spinal Diseases; Syncope; Tomography, X-Ray Computed; Young Adult
PubMed: 33540088
DOI: 10.1016/j.wneu.2021.01.084 -
European Heart Journal May 2021Head-up tilt test (TT) has been used for >50 years to study heart rate/blood pressure adaptation to positional changes, to model responses to haemorrhage, to assess...
Head-up tilt test (TT) has been used for >50 years to study heart rate/blood pressure adaptation to positional changes, to model responses to haemorrhage, to assess orthostatic hypotension, and to evaluate haemodynamic and neuroendocrine responses in congestive heart failure, autonomic dysfunction, and hypertension. During these studies, some subjects experienced syncope due to vasovagal reflex. As a result, tilt testing was incorporated into clinical assessment of syncope when the origin was unknown. Subsequently, clinical experience supports the diagnostic value of TT. This is highlighted in evidence-based professional practice guidelines, which provide advice for TT methodology and interpretation, while concurrently identifying its limitations. Thus, TT remains a valuable clinical asset, one that has added importantly to the appreciation of pathophysiology of syncope/collapse and, thereby, has improved care of syncopal patients.
Topics: Autonomic Nervous System Diseases; Heart Rate; Humans; Hypotension, Orthostatic; Syncope; Tilt-Table Test
PubMed: 33624801
DOI: 10.1093/eurheartj/ehab084 -
Praxis 2018
Topics: Adult; Anxiety Disorders; Emotions; Helplessness, Learned; Humans; Male; Middle Aged; Parent-Child Relations; Physician-Patient Relations; Psychoanalytic Interpretation; Somatoform Disorders; Syncope
PubMed: 30326813
DOI: 10.1024/1661-8157/a003083 -
European Heart Journal Jun 2022Unexplained syncope is an important clinical challenge. The influence of age at first syncope on the final syncope diagnosis is not well studied.
AIMS
Unexplained syncope is an important clinical challenge. The influence of age at first syncope on the final syncope diagnosis is not well studied.
METHODS AND RESULTS
Consecutive head-up tilt patients (n = 1928) evaluated for unexplained syncope were stratified into age groups <30, 30-59, and ≥60 years based on age at first syncope. Clinical characteristics and final syncope diagnosis were analysed in relation to age at first syncope and age at investigation. The age at first syncope had a bimodal distribution with peaks at 15 and 70 years. Prodromes (64 vs. 26%, P < 0.001) and vasovagal syncope (VVS, 59 vs. 19%, P < 0.001) were more common in early-onset (<30 years) compared with late-onset (≥60 years) syncope. Orthostatic hypotension (OH, 3 vs. 23%, P < 0.001), carotid sinus syndrome (CSS, 0.6 vs. 9%, P < 0.001), and complex syncope (>1 concurrent diagnosis; 14 vs. 26%, P < 0.001) were more common in late-onset syncope. In patients aged ≥60 years, 12% had early-onset and 70% had late-onset syncope; older age at first syncope was associated with higher odds of OH (+31% per 10-year increase, P < 0.001) and CSS (+26%, P = 0.004). Younger age at first syncope was associated with the presence of prodromes (+23%, P < 0.001) and the diagnoses of VVS (+22%, P < 0.001) and complex syncope (+9%, P = 0.018).
CONCLUSION
In patients with unexplained syncope, first-ever syncope incidence has a bimodal lifetime pattern with peaks at 15 and 70 years. The majority of older patients present only recent syncope; OH and CSS are more common in this group. In patients with early-onset syncope, prodromes, VVS, and complex syncope are more common.
Topics: Humans; Hypotension, Orthostatic; Incidence; Syncope; Syncope, Vasovagal; Tilt-Table Test
PubMed: 35139180
DOI: 10.1093/eurheartj/ehac017