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Heart Rhythm Jan 2024
Topics: Humans; Bradycardia; Syncope, Vasovagal; Atrioventricular Block; Sick Sinus Syndrome; Catheter Ablation
PubMed: 37776935
DOI: 10.1016/j.hrthm.2023.09.023 -
Journal of Cardiovascular... May 2016Humans live primarily in the upright position; as a result, there is a constant struggle between gravity and needed supply of blood flow to the brain. In certain... (Review)
Review
Humans live primarily in the upright position; as a result, there is a constant struggle between gravity and needed supply of blood flow to the brain. In certain circumstances brain blood supply may become temporarily insufficient, resulting in syncope. Among the numerous causes of syncope in humans, vasovagal syncope (VVS) is by far the most common. However, despite intensive research, many aspects of the pathophysiology of VVS remain unknown; among these, one of the least well understood is the basis for why VVS is restricted, among vertebrates, to Homo sapiens. In this manuscript we review proposals that have been offered in an attempt to address the issue of the origin of VVS and, although highly speculative, we suggest a new hypothesis (the "brain theory") to try to address the question of why humans, to the exclusion of other species, remain susceptible to VVS. This theory suggests that VVS evolved to offer protection to the brain's functional integrity under certain conditions of severe threat. Although seemingly a disadvantageous evolutionary adaptation, the faint causes the body to take on a gravitationally neutral position, and thereby provides a better chance of restoring brain blood supply and preserving long-term brain function.
Topics: Animals; Biological Evolution; Brain; Cerebrovascular Circulation; Heart; Hemodynamics; Humans; Posture; Risk Factors; Species Specificity; Syncope, Vasovagal; Tilt-Table Test
PubMed: 26840192
DOI: 10.1111/jce.12945 -
Dental Update May 2006We report the case of a 21-year-old male whose frequent episodes of loss of consciousness in the dental surgery culminated in the postponement of treatment, pending...
UNLABELLED
We report the case of a 21-year-old male whose frequent episodes of loss of consciousness in the dental surgery culminated in the postponement of treatment, pending further investigation. The patient was referred to a cardiologist and submitted to head-up tilt testing, which evoked prolonged asystole, associated with loss of consciousness and mild generalized twitching, confirming a diagnosis of malignant vasovagal syncope. Before dental treatment could be completed, the patient was successfully treated with disopyramide and dual-chamber pacemaker implantation.
CLINICAL RELEVANCE
Dentistry can predispose patients to fainting (syncope or vasovagal episode) owing to fear, pain, unusual sights and smells, anxiety, fatigue and fasting, so knowledge of extreme forms of this response are of relevance.
Topics: Adult; Dental Care; Humans; Male; Pacemaker, Artificial; Syncope, Vasovagal; Tilt-Table Test
PubMed: 16756240
DOI: 10.12968/denu.2006.33.4.246 -
Heart (British Cardiac Society) May 2015For some decades, after the introduction of the head-up tilt test into clinical practice, the clinical presentation of vasovagal syncope (VVS) has been classified as... (Review)
Review
For some decades, after the introduction of the head-up tilt test into clinical practice, the clinical presentation of vasovagal syncope (VVS) has been classified as typical (or classical) and atypical (or non-classical). Some clinical features and recent data suggest that even unexplained falls and syncope during sleeping hours may be possible clinical presentations of VVS. In recent studies, tilt testing and carotid sinus massage by means of the 'method of symptoms' were performed in one group of patients with unexplained falls and in another group with unexplained syncope (presence of prodromal symptoms). Overall, tilt testing and carotid sinus massage displayed a high positivity rate in the group of patients with unexplained falls (about 60%), which was similar to that of the unexplained syncope group. These new data seem to indicate that some unexplained falls could be cases of atypical VVS/carotid sinus syncope with retrograde amnesia. Some clinical features suggest that syncope during sleeping hours is a form of VVS with a different clinical presentation: high prevalence of autonomic prodromes, of diurnal episodes of typical VVS and specific phobias, and of positive tilt testing with severe cardioinhibition.
Topics: Accidental Falls; Adolescent; Adult; Age of Onset; Aged; Humans; Middle Aged; Sleep Wake Disorders; Syncope, Vasovagal; Young Adult
PubMed: 25792719
DOI: 10.1136/heartjnl-2014-307096 -
Transfusion Jun 2021Knowledge translation focuses on the transfer of research findings into policy and practice. To provide insight into the state of knowledge translation in blood donor...
BACKGROUND
Knowledge translation focuses on the transfer of research findings into policy and practice. To provide insight into the state of knowledge translation in blood donor research, we undertook a rapid review of a key research area in the field with high potential for translation, vasovagal reactions (VVRs). We examined the number and nature of VVR-related studies to determine the availability of research evidence, and mapped the included articles along the research-to-practice trajectory using the Knowledge to Action framework.
STUDY DESIGN AND METHODS
PubMed, PsycINFO, CINAHL, and EMBASE were searched for peer-reviewed journal articles from inception to October 2019 using the terms blood don* AND vasovagal OR faint* OR syncope.
RESULTS
A total of 176 articles met our inclusion criteria. Studies relating to VVRs increased substantially from 1942 to 2019, with 84% published in the last 20 years. Articles were predominately observation (non-intervention) studies (117; 66%), followed by intervention (knowledge inquiry) studies (31; 18%) and review (knowledge synthesis) studies (20; 11%). The evidence from intervention research was limited, with 14 strategies tested in 31 studies and often by the same research groups. Only 5 (3%) implementation and evaluation studies were found; all focused on evaluating the effects of a newly introduced intervention on VVR rates through uncontrolled or cross-sectional study designs.
DISCUSSION
VVR research is in the early stages of knowledge translation. More intervention research is needed to provide a robust evidence base as well as more published implementation research to share knowledge of translating research into policy and practice.
Topics: Blood Donors; Humans; Risk Factors; Syncope, Vasovagal; Translational Research, Biomedical
PubMed: 33797069
DOI: 10.1111/trf.16391 -
Journal of Cardiovascular... Jun 2021Cardioneuroablation (CNA) is an emerging technique being used to treat patients with cardioinhibitory vasovagal syncope (VVS). We describe a case of CNA in targeting...
BACKGROUND
Cardioneuroablation (CNA) is an emerging technique being used to treat patients with cardioinhibitory vasovagal syncope (VVS). We describe a case of CNA in targeting atrial ganglionated plexi (GP) based upon anatomical landmarks and fractionated electrogram (EGM) localization in a patient with cardioinhibitory syncope.
CASE PRESENTATION
A 20-year-old healthy female presented with malignant VVS and symptomatic sinus pauses, with the longest detected at 10 s. She underwent acutely successful CNA with demonstration of vagal response (VR) noted after ablation of left sided GP, and tachycardia noted with right sided GP ablation. All GP sites were defined by anatomical landmarks and EGM analysis. By using the fractionation mapping software of Ensite Precision mapping system with high density mapping, fragmented EGMs were successfully detected in each GP site. One month after vagal denervation, there were no recurrent syncopal episodes or sinus pauses. Longer term follow-up with implantable loop recorder is planned.
CONCLUSION
We performed CNA in a patient with VVS by utilizing a novel approach of combined use of high density mapping and fractionation mapping software. With this approach, we were able to detect fractionation in all GP sites and demonstrate acute VR. This workflow may allow for a new, standardized technique suitable for widespread use.
Topics: Adult; Catheter Ablation; Female; Humans; Syncope, Vasovagal; Vagus Nerve; Young Adult
PubMed: 33855779
DOI: 10.1111/jce.15044 -
Transfusion Sep 2023Vasovagal reactions (VVRs) are one of the primary reasons for people to stop donating blood. The aim of this study was to evaluate the impact of newly developed online... (Randomized Controlled Trial)
Randomized Controlled Trial
BACKGROUND
Vasovagal reactions (VVRs) are one of the primary reasons for people to stop donating blood. The aim of this study was to evaluate the impact of newly developed online communications on the rate of return of whole-blood (WB) and plasma donors who experienced a VVR.
STUDY DESIGN AND METHODS
First-time and experienced WB and plasma donors who had a VVR without a loss of consciousness in the previous 3 days were randomly allocated to receive (a) an SMS sent 1-4 days post-VVR (n = 2303), (b) an email sent 6-10 days post-VVR (n = 2360), (c) both the SMS and the email (n = 2248), or (d) business-as-usual donor retention communications (control; n = 2557). Donation data were extracted to determine subsequent donation attempts.
RESULTS
For return within 3 months, WB donors in the Email Only condition had significantly increased odds of returning (OR: 1.26, 95%CI: 1.01-1.56). Subgroup analysis within WB donors showed increased odds of return for women sent the SMS and Email (OR: 1.50, 95%CI: 1.14-1.96) or the Email Only (OR: 1.44, 95%CI: 1.10-1.89), and for first-time donors sent the Email Only (OR: 1.48, 95%CI: 1.07-2.05). At 6 months, only first-time WB donors in the Email Only condition had significantly increased odds of returning (OR: 1.30, 95%CI: 1.01-1.69). No significant effects of the intervention were found for immediate or intermediate return for plasma donors.
DISCUSSION
Sending an email addressing common donor concerns regarding VVRs increases WB donor retention, but additional strategies are needed for the effects to last and to retain plasma donors.
Topics: Humans; Female; Blood Donors; Syncope, Vasovagal; Communication
PubMed: 37493388
DOI: 10.1111/trf.17494 -
Scientific Reports Jun 2023Around one-third of adults are scared of needles, which can result in adverse emotional and physical responses such as dizziness and fainting (e.g. vasovagal reactions;...
Around one-third of adults are scared of needles, which can result in adverse emotional and physical responses such as dizziness and fainting (e.g. vasovagal reactions; VVR) and consequently, avoidance of healthcare, treatments, and immunizations. Unfortunately, most people are not aware of vasovagal reactions until they escalate, at which time it is too late to intervene. This study aims to investigate whether facial temperature profiles measured in the waiting room, prior to a blood donation, can be used to classify who will and will not experience VVR during the donation. Average temperature profiles from six facial regions were extracted from pre-donation recordings of 193 blood donors, and machine learning was used to classify whether a donor would experience low or high levels of VVR during the donation. An XGBoost classifier was able to classify vasovagal groups from an adverse reaction during a blood donation based on this early facial temperature data, with a sensitivity of 0.87, specificity of 0.84, F1 score of 0.86, and PR-AUC of 0.93. Temperature fluctuations in the area under the nose, chin and forehead have the highest predictive value. This study is the first to demonstrate that it is possible to classify vasovagal responses during a blood donation using temperature profiles.
Topics: Adult; Humans; Needles; Temperature; Syncope, Vasovagal; Syncope; Vertigo
PubMed: 37316637
DOI: 10.1038/s41598-023-36207-z -
Transfusion Nov 2013There is a paucity of studies on the magnitude of reduction of vasovagal reaction by reduced collection volume. This study was thus conducted to determine the difference...
BACKGROUND
There is a paucity of studies on the magnitude of reduction of vasovagal reaction by reduced collection volume. This study was thus conducted to determine the difference in reaction rates between two collection volumes among the young first-time donors who are at particular risk of reaction.
STUDY DESIGN AND METHODS
This retrospective study analyzed 38,436 whole blood donations made by young (aged 16 to 18 years) first-time donors. The effect of collection volume on vasovagal reaction was compared among different weight subgroups for both sexes by chi-square test.
RESULTS
For females in all weight subgroups and two of the male lower-weight subgroups, the reduction percentages ranged from 35% to 58% (p < 0.05). It was also noted that, among the females, a higher weight was associated with a higher percent reduction in the reaction rate.
CONCLUSION
With reduced collection volume, this study detected large and significant reduction in reaction rates among all females, as well as lower-weight males.
Topics: Adolescent; Blood Donors; Blood Specimen Collection; Female; Humans; Male; Retrospective Studies; Syncope, Vasovagal
PubMed: 23451762
DOI: 10.1111/trf.12134 -
Critical Pathways in Cardiology Sep 2023Vasovagal syncope (VVS) is largely a benign condition focused on patient education, lifestyle modification, and avoidance of triggers. However, a subset of patients may... (Review)
Review
Vasovagal syncope (VVS) is largely a benign condition focused on patient education, lifestyle modification, and avoidance of triggers. However, a subset of patients may benefit from permanent pacemaker placement. Commonly, patients with VVS are younger and those requiring pacing have symptoms associated with severe cardioinhibitory syncope. With the advent of leadless pacemaker systems, a lot of the risks associated with traditional transvenous pacemaker systems are mitigated. In this article, we provide a comprehensive review of the data available for the treatment of cardioinhibitory vasovagal syncope using leadless pacemaker systems.
Topics: Humans; Syncope, Vasovagal; Cardiac Pacing, Artificial; Pacemaker, Artificial
PubMed: 37249900
DOI: 10.1097/HPC.0000000000000325