Effectiveness of physical counterpressure maneuvers in preventing vasovagal syncope: the Physical Counterpressure Manoeuvres Trial (PC-Trial)

Adult vasovagal syncope with abdominal pain diagnosed by head-up tilt combined with transcranial doppler: a preliminary study

BACKGROUND

Syncope is a common condition that increases the risk of injury and reduces the quality of life. Abdominal pain as a precursor to vasovagal syncope (VVS) in adults is rarely reported and is often misdiagnosed.​.

METHODS

We present three adult patients with VVS and presyncopal abdominal pain diagnosed by synchronous multimodal detection (transcranial Doppler [TCD] with head-up tilt [HUT]) and discuss the relevant literature.

RESULTS

Case 1: A 52-year-old man presented with recurrent decreased consciousness preceded by six months of abdominal pain. Physical examinations were unremarkable. Dynamic electrocardiography, echocardiography, head and neck computed tomography angiography, magnetic resonance imaging (MRI), and video electroencephalogram showed no abnormalities. Case 2: A 57-year-old woman presented with recurrent syncope for 30 + years, accompanied by abdominal pain. Physical examination, electroencephalography, and MRI showed no abnormalities. Echocardiography showed large right-to-left shunts. Case 3: A 30-year-old woman presented with recurrent syncope for 10 + years, with abdominal pain as a precursor. Physical examination, laboratory analysis, head computed tomography, electrocardiography, and echocardiography showed no abnormalities. Syncope secondary to abdominal pain was reproduced during HUT. Further, HUT revealed vasovagal syncope, and synchronous TCD showed decreased cerebral blood flow; the final diagnosis was VVS in all cases.

CONCLUSIONS

Abdominal pain may be a precursor of VVS in adults, and our findings enrich the clinical phenotypic spectrum of VVS. Prompt recognition of syncopal precursors is important to prevent incidents and assist in treatment decision-making. Abdominal pain in VVS may be a sign of sympathetic overdrive. Synchronous multimodal detection can help in diagnosing VVS and understanding hemodynamic mechanisms.

The efficacy of non-pharmacological and non-pacing therapies in preventing vasovagal syncope: Tilt training, physical counter pressure maneuvers, and yoga - A systematic review and meta-analysis

BACKGROUND

Vasovagal syncope (VVS) is a prevalent condition characterized by a sudden drop in blood pressure and heart rate, leading to a brief loss of consciousness and postural control. Recurrent episodes of VVS significantly impact the quality of life and are a common reason for emergency department visits. Non-pharmacological interventions, such as tilt training, physical counter pressure maneuvers, and yoga, have been proposed as potential treatments for VVS. However, their efficacy in preventing VVS remains uncertain.

METHODS

A systematic review and meta-analysis were conducted following PRISMA guidelines. PubMed, Web of Science, and Embase were searched up to March 2023 for randomized controlled trials comparing non-pharmacological interventions with control in preventing VVS recurrence. The primary outcome was the recurrence rate of VVS episodes.

RESULTS

A total of 1130 participants from 18 studies were included in the meta-analysis. The overall mean effect size for non-pharmacological interventions versus control was 0.245 (95 % CI: 0.128-0.471, p-value <0.001). Subgroup analysis showed that yoga had the largest effect size (odds ratio 0.068, 95 % CI: 0.018-0.250), while tilt training had the lowest effect size (odds ratio 0.402, 95 % CI: 0.171-0.946) compared to control. Physical counter pressure maneuvers demonstrated an odds ratio of 0.294 (95 % CI: 0.165-0.524) compared to control.

CONCLUSION

Non-pharmacological interventions show promise in preventing recurrent VVS episodes. Yoga, physical counter pressure maneuvers, and tilt training can be considered as viable treatment options. Further research, including randomized studies comparing pharmacological and non-pharmacological approaches, is needed to evaluate the safety and efficacy of these interventions for VVS treatment.

Characteristics of deceleration capacity and deceleration runs in vasovagal syncope

PURPOSE

Increased vagal activity plays a prominent role in vasovagal syncope (VVS). The aim of this study was to characterize vagal function in VVS by evaluating the heart rate (HR) deceleration capacity (DC) and the HR deceleration runs (DRs) in patients with VVS between attacks.

METHODS

A total of 188 consecutive VVS patients were enrolled in the study, of whom 129 had positive head-up tilt test (HUTT); 132 healthy participants were enrolled as controls. DC, DRs (DR2, i.e., episodes of 2 consecutive beat-to-beat HR decelerations), and the sum of DR8-10 (very long DR [VLDR]) were calculated using 24-h electrograms. Clinical characteristics, DC, and DRs were compared among syncope groups and controls.

RESULTS

Patients with VVS had higher DC (10.63 ± 2.1 vs. 6.58 ± 1.7 ms; P < 0.001) and lower minimum HR and DR6-10 than controls. No significant differences in DC or DR6-10 were found between the patients with positive and those with negative HUTT results. In multivariate logistic regression analysis, minimum HR ≥ 40 bpm (odds ratio [OR] 0.408, 95% confidence interval [CI] 0.167-0.989; P = 0.048), daytime DC ≥ 7.37 ms (OR 3.040, 95% CI 1.220-7.576; P = 0.013), and VLDR ≥ 0.046% (OR 0.306, 95% CI 0.138-0.679; P = 0.004) were demonstrated to be risk factors significantly associated with VVS.

CONCLUSION

Compared to healthy controls, patients with VVS demonstrated distinct HR deceleration profiles between attacks, including overall higher DC and lower DR6-10.

Twenty-five years of research on syncope

Over the last 25 years, the Europace journal has greatly contributed to dissemination of research and knowledge in the field of syncope. More than 400 manuscripts have been published in the journal. They undoubtedly improved our understanding of syncope. This symptom is now clearly differentiated from other forms of transient loss of consciousness. The critical role of vasodepression and/or cardioinhibition as final mechanisms of reflex syncope is emphasized. Current diagnostic approach sharply separates between cardiac and autonomic pathways. Physiologic insights have been translated, through rigorously designed clinical trials, into non-pharmacological or pharmacological interventions and interventional therapies. The following manuscript is intended to give the reader the current state of the art of knowledge of syncope by highlighting landmark contributions of the Europace journal.

A Post-Pandemic Enigma: The Cardiovascular Impact of Post-Acute Sequelae of SARS-CoV-2

COVID-19 has become the first modern-day pandemic of historic proportion, affecting >600 million individuals worldwide and causing >6.5 million deaths. While acute infection has had devastating consequences, postacute sequelae of SARS-CoV-2 infection appears to be a pandemic of its own, impacting up to one-third of survivors and often causing symptoms suggestive of cardiovascular phenomena. This review will highlight the suspected pathophysiology of postacute sequelae of SARS-CoV-2, its influence on the cardiovascular system, and potential treatment strategies.

Pharmacologic prevention of recurrent vasovagal syncope: A systematic review and network meta-analysis of randomized controlled trials

Vasovagal syncope (VVS) is a transient loss of consciousness that currently imposes a high burden on health care systems with limited evidence of the comparative efficacy of available pharmacologic interventions. This study aims to compare all pharmacologic therapies suggested in randomized controlled trials (RCTs) through systematic review and network meta-analysis. A systematic search in PubMed, Embase, Web of Science, and Cochrane Library was conducted to identify RCTs evaluating pharmacologic therapies for patients with VVS. The primary outcome was spontaneous VVS recurrence. The secondary outcome was a positive head-up tilt test (HUTT) after receiving intervention, regarded as a lower level of evidence. Pooled risk ratio (RR) with 95% confidence interval (CI) was calculated using random-effect network meta-analysis. Pairwise meta-analysis for comparison with placebo was also performed when applicable. The surface under the cumulative ranking curve analysis was conducted to rank the treatments for each outcome. Twenty-eight studies with 1744 patients allocated to different medications or placebo were included. Network meta-analysis of the reduction in the primary outcome showed efficacy for midodrine (RR 0.55; 95% CI 0.35-0.85) and fluoxetine (especially in patients with concomitant anxiety) (RR 0.36; 95% CI 0.16-0.84). In addition, midodrine and atomoxetine were superior to other treatment options, considering positive HUTT (RR 0.37; 95% CI 0.23-0.59; and RR 0.49; 95% CI 0.28-0.86, respectively). Overall, midodrine was the only agent shown to reduce spontaneous syncopal events. Fluoxetine also seems to be beneficial but should be studied further in RCTs. Our network meta-analysis did not find evidence of the efficacy of any other medication.

Exaggerated postural sway improves orthostatic cardiovascular and cerebrovascular control

Introduction

Healthy individuals with poor cardiovascular control, but who do not experience syncope (fainting), adopt an innate strategy of increased leg movement in the form of postural sway that is thought to counter orthostatic (gravitational) stress on the cardiovascular system. However, the direct effect of sway on cardiovascular hemodynamics and cerebral perfusion is unknown. If sway produces meaningful cardiovascular responses, it could be exploited clinically to prevent an imminent faint.

Methods

Twenty healthy adults were instrumented with cardiovascular (finger plethysmography, echocardiography, electrocardiogram) and cerebrovascular (transcranial Doppler) monitoring. Following supine rest, participants performed a baseline stand (BL) on a force platform, followed by three trials of exaggerated sway (anterior-posterior, AP; mediolateral, ML; square, SQ) in a randomized order.

Results

All exaggerated postural sway conditions improved systolic arterial pressure (SAP, p = 0.001) responses, while blunting orthostatic reductions in stroke volume (SV, p < 0.01) and cerebral blood flow (CBFv, p < 0.05) compared to BL. Markers of sympathetic activation (power of low-frequency oscillations in SAP, p < 0.001) and maximum transvalvular flow velocity (p < 0.001) were reduced during exaggerated sway conditions. Responses were dose-dependent, with improvements in SAP (p < 0.001), SV (p < 0.001) and CBFv (p = 0.009) all positively correlated with total sway path length. Coherence between postural movements and SAP (p < 0.001), SV (p < 0.001) and CBFv (p = 0.003) also improved during exaggerated sway.

Discussion

Exaggerated sway improves cardiovascular and cerebrovascular control and may supplement cardiovascular reflex responses to orthostatic stress. This movement provides a simple means to boost orthostatic cardiovascular control for individuals with syncope, or those with occupations that require prolonged motionless standing.

Current approach to the treatment of vasovagal syncope in adults

Vasovagal syncope (VVS) is the most common cause of transient loss of consciousness. Although not associated with mortality, it causes injuries, reduces quality of life, and is associated with anxiety and depression. The European and North American cardiac societies recently published syncope clinical practice guidelines. Most patients with VVS do well after specialist evaluation, reassurance and education. Adequate hydration, increased salt intake when not contraindicated, and careful withdrawal of diuretics and specific hypotension-inducing drugs are a reasonable initial strategy. Physical counterpressure maneuvers might be helpful but can be of limited efficacy in older patients and those with short or no prodromes. Orthostatic training lacks long term efficacy and is troubled by non-compliance. Yoga might be helpful, although the biomedical mechanism is unknown. Almost a third of VVS patients continue to faint despite these conservative measures. Metoprolol was not helpful in a pivotal randomized clinical trial. Fludrocortisone and midodrine significantly reduce syncope recurrences with tolerable side effects, when titrated to target doses. Pacing therapy with specialized sensors appears promising in carefully selected population who have not responded conservative measures. Cardioneuroablation may be helpful but has not been studied in a formal clinical trial.

Vasovagal Syncope during Office Hysteroscopy—A Frequently Overlooked Unpleasant Complication

Due to technological advancements in miniaturization of instruments and improved optics, the number of office hysteroscopic procedures has increased over time. Office hysteroscopy is preferred due to avoidance of general anesthesia and decreased overall cost. Vasovagal syncope has been implied as the most common complication. Vasovagal syncope is associated with inappropriate reflex vasodilation and bradycardia in the setting of an acute malfunction between the autonomic nervous system and the cardiovascular system; however, there is no mortality associated with vasovagal syncope. A management strategy for acute vasovagal reflex during office hysteroscopy is proposed in order to manage this common complication.

Counter pressure maneuvers for syncope prevention: A semi-systematic review and meta-analysis

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 (N = 28), the community setting (N = 4), both laboratory and community settings (N = 3), and during blood donation (N = 10). CPM improved standing systolic blood pressure (+ 14.8 ± 0.6 mmHg, p < 0.001) and heart rate (+ 1.4 ± 0.5 bpm, p = 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.

Orthostatic intolerance in post-concussion patients

Orthostatic intolerance (OI) following pediatric concussion is not well understood. Assessing the prevalence of concussion-related OI and how it compares to non-concussion-related OI will improve care for patients suffering with these symptoms. OBJECTIVE: We set out to describe concussion-related OI in adolescence, with particular emphasis on time to recovery and differences from non-concussion-related OI (including male vs. female prevalence). Retrospective chart reviews were completed on post-concussion patients endorsing symptoms of OI. The patients' sex, sport history, previous concussions, time since injury, and recovery time were analyzed and compared between males and females as well as against general OI statistics. Thirty-nine pediatric patients, representing 8.7% of all new patients referred to a specialized concussion clinic over a 13-month interval, were included in the chart review. Mean age of onset was 15.0 ± 2.5 years and 18 (46%) were males. The median times from evaluation to symptom resolution were 120 days. Of 18 patients who completed head-up tilt table testing, 17 (94%) had orthostatic tachycardic response (>40 bpm heart rate increment). Post-concussive OI differs from other orthostatic intolerance etiologies, lacking a strong female predominance and exhibiting a shorter time course to recovery compared to other etiologies of OI (but longer recovery time compared to concussion patients in general). Clinical orthostatic vital signs may not be sensitive for diagnosing orthostatic intolerance in athletes, likely due to higher vagal tone and more efficient skeletal muscle pump.

Compression stockings for treating vasovagal syncope (COMFORTS-II) trial: Rationale and design of a triple-blind, multi-center, randomized controlled trial

BACKGROUND

Reduced venous return is an important trigger of vasovagal syncope (VVS). Elastic compression stockings (ECS) can modify venous return and be of therapeutic interest; however, evidence for ECS efficacy in VVS is scarce. This randomized controlled trial was designed to address the issue.

METHODS

COMFORTS-II is a multicenter, triple-blind, parallel design, randomized controlled trial aimed to assess the efficacy of ECS in preventing VVS recurrences. Using central online randomization, 268 participants will be allocated to 2 arms (1:1 ratio), wearing intervention ECS (25-30 mm Hg pressure) or sham ECS (≤10 mm Hg pressure). All participants will receive standard VVS treatment in the form of education, and lifestyle modification recommendations (drinking 2-3 l/d of fluids and consuming 10 g/d-roughly half a tablespoon-of table salt). Adherence to ECS treatment will be evaluated through diary sheets, and compared between study arms. Follow-up continues for 1 year, and is conducted via a 24/7 phone line available to patients and trimonthly visits. The co-primary outcomes are proportion of participants with any syncopal recurrence and time to first syncopal episode. Secondary outcomes include frequency of VVS spells, time intervals between recurrences, and incidence of any patient-reported adverse effects.

CONCLUSION

To the best of our knowledge, COMFORTS-II is the first clinical trial to assess ECS efficacy among patients with VVS, addressing an important gap in evidence for VVS treatments.

Neurally Mediated Syncope in Children and Adolescents: An Updated Narrative Review

Syncope presents a proportion of up to 25% among children and adolescents and accounts for 0.9% of emergency room visits. Its most frequent aetiology is neurally mediated syncope, which includes vasovagal syncope and orthostatic hypotension. Up to 70% of the paediatric population with reflex syncope is female. There are usually precipitating factors and prodromes. This mini-review will discuss the particularities of the clinical presentation, diagnosis, modified Calgary score, indications and accuracy of the head-up tilt test, classification, and pathophysiology in four sequential phases. Prognostic data and the non-pharmacological and pharmacological approaches will also be reviewed and differences regarding reflex syncope in adults will be discussed.

Risk stratification of syncope: Current syncope guidelines and beyond

Syncope is an alarming event carrying the possibility of serious outcomes, including sudden cardiac death (SCD). Therefore, immediate risk stratification should be applied whenever syncope occurs, especially in the Emergency Department, where most dramatic presentations occur. It has long been known that short- and long-term syncope prognosis is affected not only by its mechanism but also by presence of concomitant conditions, especially cardiovascular disease. Over the last two decades, several syncope prediction tools have been developed to refine patient stratification and triage patients who need expert in-hospital care from those who may receive nonurgent expert care in the community. However, despite promising results, prognostic tools for syncope remain challenging and often poorly effective. Current European Society of Cardiology syncope guidelines recommend an initial syncope workup based on detailed patient's history, physical examination supine and standing blood pressure, resting ECG, and laboratory tests, including cardiac biomarkers, where appropriate. Subsequent risk stratification based on screening of features aims to identify three groups: high-, intermediate- and low-risk. The first should immediately be hospitalized and appropriately investigated; intermediate group, with recurrent or medium-risk events, requires systematic evaluation by syncope experts; low-risk group, sporadic reflex syncope, merits education about its benign nature, and discharge. Thus, initial syncope risk stratification is crucial as it determines how and by whom syncope patients are managed. This review summarizes the crucial elements of syncope risk stratification, pros and cons of proposed risk evaluation scores, major challenges in initial syncope management, and how risk stratification impacts management of high-risk/recurrent syncope.

Effect of Yoga on Clinical Outcomes and Quality of Life in Patients With Vasovagal Syncope (LIVE-Yoga)

OBJECTIVES

This study aims to determine the impact of yoga as an adjunct to standard therapy versus standard therapy alone on the symptomatic burden in patients with recurrent vasovagal syncope (VVS).

BACKGROUND

There is a significant reduction in the quality of life (QoL) of patients with recurrent VVS. Existing management therapies have been largely ineffective. Recent trials have demonstrated the efficacy of yoga in diseases with autonomic imbalance, suggesting its possible utility in VVS.

METHODS

Patients with recurrent VVS were randomized to receive either a specialized yoga training program in addition to current guideline-based therapy (intervention arm, group 1) or current guideline-based therapy alone (control arm, group 2). The primary outcome was a composite of the number of episodes of syncope and presyncope at 12 months. Secondary outcomes included QoL assessment by World Health Organization Quality of Life Brief Field questionnaire (WHOQoL-BREF) scores and Syncope Functional Status Questionnaire scores at 12 months, head up tilt test, and heart rate variability at 6 weeks.

RESULTS

A total of 55 patients underwent randomization. The mean number of syncopal or presyncopal events at 12 months was 0.7 ± 0.7 in the intervention arm compared to 2.52 ± 1.93 in the control arm (P < 0.01). In the intervention arm, 13 (43.3%) patients remained free of events versus 4 (16.0%) patients in the control arm (P = 0.02). QoL at 12 months showed significant improvement of all Syncope Functional Status Questionnaire scores and 2 domains of WHOQoL-BREF scores (P < 0.05).

CONCLUSIONS

Yoga as adjunctive therapy is superior to standard therapy alone in reducing the symptomatic burden and improving QoL in patients with recurrent VVS.

Management of vasovagal syncope

Vasovagal syncope (VVS) is a very common form of fainting. Treatment begins with patient education about the mechanism of fainting, and the non-lethal nature of vasovagal syncope. In this article, we review several non-pharmacological approaches that form the foundation of our current treatments. These include increases in dietary salt and water intake, the use of compression garments, physical counter-maneuvers and tilt-training. When these approaches are inadequate, medications can sometimes be effective. While the evidence base for the pharmacological treatment of VVS is modest, recent trial data have found drugs to be useful in placebo-controlled randomized trials. For select patients, and those patients more refractory to medications, procedural treatments may be an option. In this review, we discuss the current state of evidence for the non-pharmacological and pharmacological treatments for VVS, as well as some novel, emerging therapies for VVS.

Management strategies for vasovagal syncope

Vasovagal syncope (VVS) (or neurocardiogenic syncope) is a common clinical condition that is challenging to both physicians and patients alike. Severe episodes of recurrent syncope can result in physical injury as well as psychological distress. This article provides a brief overview of current management strategies and a detailed overview of therapeutic modalities such as closed loop stimulation (CLS) and cardioneuroablation (CNA).

Midodrine for the Prevention of Vasovagal Syncope : A Randomized Clinical Trial

BACKGROUND

Recurrent vasovagal syncope is common, responds poorly to treatment, and causes physical trauma and poor quality of life. Midodrine prevents hypotension and syncope during tilt tests in patients with vasovagal syncope.

OBJECTIVE

To determine whether midodrine can prevent vasovagal syncope in usual clinical conditions.

DESIGN

Randomized, double-blind, placebo-controlled clinical trial. (ClinicalTrials.gov: NCT01456481).

SETTING

25 university hospitals in Canada, the United States, Mexico, and the United Kingdom.

PATIENTS

Patients with recurrent vasovagal syncope and no serious comorbid conditions.

INTERVENTION

Patients were randomly assigned 1:1 to placebo or midodrine and followed for 12 months.

MEASUREMENTS

The primary outcome measure was the proportion of patients with at least 1 syncope episode during follow-up.

RESULTS

The study included 133 patients who had had a median of 6 syncope episodes in the prior year (median age, 32 years; 73% female). Compared with patients receiving placebo, fewer patients receiving midodrine had at least 1 syncope episode (28 of 66 [42%] vs. 41 of 67 [61%]). The relative risk was 0.69 (95% CI, 0.49 to 0.97; P = 0.035). The absolute risk reduction was 19 percentage points (CI, 2 to 36 percentage points), and the number needed to treat to prevent 1 patient from having syncope was 5.3 (CI, 2.8 to 47.6). The time to first syncope was longer with midodrine (hazard ratio, 0.59 [CI, 0.37 to 0.96]; P = 0.035; log-rank P = 0.031). Adverse effects were similar in both groups.

LIMITATION

Small study size, young and healthy patients, relatively short observation period, and high proportion of patients from 1 center.

CONCLUSION

Midodrine can reduce the recurrence of syncope in healthy, younger patients with a high syncope burden.

PRIMARY FUNDING SOURCE

The Canadian Institutes of Health Research.

Syncope in Dental Practices: A Systematic Review on Aetiology and Management

INTRODUCTION

This systematic review aimed to give an overview of the current evidence surrounding the aetiology and management in terms of treatment and prevention of syncope in dental practices. Alongside the occurrence, the practitioner's competence, and the association between syncope and local anaesthetics were discussed.

METHODS

An electronic search in EMBASE, Web of Science, PubMed, Cochrane databases and a hand search were performed by 2 independent reviewers to identify studies up to November 2019. Eligibility criteria were applied and relevant data was extracted. Inclusion criteria covered all types of dental treatment under local anaesthesia or conscious sedation performed by a wide range of oral health care workers in their practices. Risk of bias of the included studies was assessed using the methodological tools recommend by Zeng et al.¹ No restrictions were made to exclude papers from qualitive analysis based on risk of bias assessment.

RESULTS

The search yielded a total of 18 studies for qualitative analysis. With the exception of one prospective cohort study, all articles were considered having a high risk of bias. Meta-analysis showed that dentists encountered on average 1.2 cases of syncope per year. The male gender (RR = 2.69 [1.03, 7.02]), dental fear (RR = 3.55 [2.22, 5.70]), refusal of local anaesthesia in non-acute situations (OR = 12.9) and the use of premedication (RR = 4.70, [1.30, 16.90]) increased the risk for syncope. Treatment and prevention were underreported as both were solely discussed in one study. The supine recovery position with raised legs and oxygen administration (15l/min) was presented as an effective treatment. The Medical Risk-Related History (MRRH) system was proposed as prevention protocol, yet this protocol was ineffective in reducing incidence rates (p = 0.27). The majority of dentists (79.2%) were able to diagnose syncope, yet most (86%) lacked the skills for appropriate treatment. Only 57,6% of dental practices were equipped with an oxygen cylinder.

CONCLUSIONS

Syncope is the most common emergency in dental practices. Nonetheless, the vast majority of dentists do not seem competent nor prepared to manage this emergency. Psychogenic factors seem to play an important role in provoking syncope. Placing the patient in a supine reclined position with raised legs in combination with the administration of oxygen seems effective for regaining consciousness. Although valuable in many aspects, risk assessment by medical history taking is not proven to result in fewer episodes. The strength of these conclusions is low based on GRADE guidelines.².

Diagnostic yield and accuracy in a tertiary referral syncope unit validating the ESC guideline on syncope: a prospective cohort study

Aims 

To assess in patients with transient loss of consciousness the diagnostic yield, accuracy, and safety of the structured approach as described in the ESC guidelines in a tertiary referral syncope unit.

Methods and results 

Prospective cohort study including 264 consecutive patients (≥18 years) referred with at least one self-reported episode of transient loss of consciousness and presenting to the syncope unit between October 2012 and February 2015. The study consisted of three phases: history taking (Phase 1), autonomic function tests (AFTs) (Phase 2), and after 1.5-year follow-up with assessment by a multidisciplinary committee (Phase 3). Diagnostic yield was assessed after Phases 1 and 2. Empirical diagnostic accuracy was measured for diagnoses according to the ESC guidelines after Phase 3. The diagnostic yield after Phase 1 (history taking) was 94.7% (95% CI: 91.1–97.0%, 250/264 patients) and increased to 97.0% (93.9–98.6%, 256/264 patients) after Phase 2. The overall diagnostic accuracy (as established in Phase 3) of the Phases 1 and 2 diagnoses was 90.6% (95% CI: 86.2–93.8%, 232/256 patients). No life-threatening conditions were missed. Three patients died, two unrelated to the cause of transient loss of consciousness, and one whom remained undiagnosed.

Conclusion 

A clinical work-up at a tertiary syncope unit using the ESC guidelines has a high diagnostic yield, accuracy, and safety. History taking (Phase 1) is the most important diagnostic tool. Autonomic function tests never changed the Phase 1 diagnosis but helped to increase the certainty of the Phase 1 diagnosis in many patients and yield additional diagnoses in patients who remained undiagnosed after Phase 1. Diagnoses were inaccurate in 9.4%, but no serious conditions were missed. This is adequate for clinical practice.

Syncope in Commercial Pilots and New Regulatory Guidance

INTRODUCTION: Syncope is both incapacitating and unpredictable, presenting a significant challenge in aircrew assessment. Previous UK Civil Aviation Authority (CAA) guidance lacked transparency and relied heavily on specialist in-house cardiology and neurology opinion. A new algorithm was developed which elaborated and formalized the decision-making process. An analysis of its impact on historic cases was undertaken to ensure it aligned with previous certificatory outcomes.METHODS: The medical literature on syncope and the approaches of other national aviation authorities were reviewed to help inform the development of a new algorithm. Using syncope cases in the CAA database, regulatory outcomes generated using the new algorithm were compared with previous decisions in terms of time off from flying (TOF) and Operational Multi-Crew Limitation (OML) duration.RESULTS: There were 40 historic syncope cases (25 existing certificate holders,15 initial applicants) which were reassessed using the new algorithm. The mean TOF for existing pilots using the new algorithm was 7.1 9.8 (mean SD) vs. 4.2 3.5 mo under the old guidance with an OML duration of 21.4 34.9 vs. 24.5 25.2 mo. One less initial applicant experienced a delay to certification. Four cases with underlying pathology were detected using old and new guidance.DISCUSSION: The reassessment of cases showed no statistically significant difference in TOF and OML duration; this is a positive finding from a regulatory perspective, enabling algorithm-led decision-making with less reliance on in-house expertise. A similar approach may be useful in future updates to other areas of regulatory practice.Anderton RA, Mitchell SJ, ONunain SS. Syncope in commercial pilots and new regulatory guidance. Aerosp Med Hum Perform. 2021; 92(8):642649.

Comparison of Outcomes with Midodrine and Fludrocortisone for Objective Recurrence in Treating Syncope (COMFORTS trial): Rationale and design for a multi-center randomized controlled trial

BACKGROUND

The cornerstone of the treatment of vasovagal syncope (VVS) is lifestyle modifications; however, some patients incur life-disturbing attacks despite compliance with these treatments which underscores the importance of pharmacological interventions.

METHODS

In this open-label multi-center randomized controlled trial, we are going to randomize 1375 patients with VVS who had ≥2 syncopal episodes in the last year into three parallel arms with a 2:2:1 ratio to receive midodrine, fludrocortisone, or no medication. All patients will be recommended to drink 2 to 3 liters of fluids per day, consume 10 grams of NaCl per day, and practice counter-pressure maneuvers. In medication arms, patients will start on 5 mg of midodrine TDS or 0.05 mg of fludrocortisone BD. After one week the dosage will be up-titrated to midodrine 30 mg/day and fludrocortisone 0.2 mg/day. Patient tolerance will be the principal guide to dosage adjustments. We will follow-up the patients on 3, 6, 9, and 12 months after randomization. The primary outcome is the time to first syncopal episode. Secondary outcomes include the recurrence rate of VVS, time interval between first and second episodes, changes in quality of life (QoL), and major and minor adverse drug reactions. QoL will be examined by the 36-Item Short Form Survey questionnaire at enrollment and 12 months after randomization.

CONCLUSION

The COMFORTS trial is the first study that aims to make a head-to-head comparison between midodrine and fludrocortisone, against a background of lifestyle modifications for preventing recurrences of VVS and improving QoL in patients with VVS.

Atomoxetine as an adjunct to nonpharmacological treatments for preventing vasovagal attacks in patients with recurrent vasovagal syncope: A pilot randomized-controlled trial

BACKGROUND

Despite the reduced quality of life in patients with recurrent vasovagal syncope (VVS), pharmacologic treatment options remain limited. Studies indicate that norepinephrine reuptake inhibition reduces tilt-induced syncope/pre-syncope. This study aimed to evaluate the effects of atomoxetine on syncopal/pre-syncopal episodes in patients with recurrent VVS.

METHODS

In a placebo-controlled trial, we randomized patients with newly diagnosed VVS who experienced ≥3 syncopal episodes in the past three months to receive either atomoxetine (20 mg daily for two weeks followed by 40 mg daily for two weeks) or placebo. The primary endpoint was the combined number of syncopal and pre-syncopal episodes.

RESULTS

Among 843 patients initially screened, 46 were randomized (N = 23 in each group) and reevaluated at one and three months. Compared to placebo, atomoxetine significantly reduced the primary endpoint after three months (P < 0.001). In the atomoxetine arm, the median time to first pre-syncopal episode was 55 days (95% confidence interval (CI): 41.21-68.79), while this was 27 days (95% CI: 14.48-39.52) for the placebo group (P < 0.001). In a subgroup analysis of patients with systolic blood pressure < 110 mmHg, atomoxetine reduced the primary endpoint, and the number of syncopal and pre-syncopal episodes after one and three months. In this subgroup, the median time to first pre-syncopal attack was 56 days in the atomoxetine group as opposed to 9 days in the placebo group.

CONCLUSIONS

In this pilot study, the promising effects of atomoxetine in reducing syncopal/pre-syncopal episodes in recurrent VVS, especially with low blood pressure phenotype, warrant the conduction of future randomized trials.

Tilt testing remains a valuable asset

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.

Treatment of Vasovagal Syncope Associated with Asystole: Literature Review and Case Report of Long-term Follow-up

Vasovagal syncope (VVS) can occur in every third of human population. Clinical symptoms of VVS areas a result of arterial hypotension with critical global cerebral hypoperfusion due to vasodilatation and bradicardia. Bradicardia is manifested as sinus node dysfunction and atrioventricular conduction disturbances due to activation of nervus vagus. Asystole can take place in some cases. Lack of efficacy of permanent pacemaker founds in patients to prevent of VVS. The results of double blind placebo controlled studies, European and American expert's opinions, probable causes of lack of efficacy of pacemakers in such category of patients and way of solution of this problem are discussed in the review. Syncope recurrences in spite of pacemaker implantation, risk of surgery complications and good life prognosis are arguments for therapeutic approach, now suitable for the most of patients with VVS. Case report (VVS with asystole but without of pacemaker implantation) with successful follow-up is analyzed in the article.

Midodrine treatment in children with recurrent vasovagal syncope

BACKGROUND

Vasovagal syncope is the most common cause of syncope in childhood and its treatment is not at a satisfactory level yet. We aimed to investigate patients who were diagnosed with vasovagal syncope, did not benefit from conventional treatment, received midodrine treatment, and to evaluate their response to midodrine treatment.

METHODS

Files of 24 patients who were diagnosed with recurrent vasovagal syncope, did not benefit from non-pharmacological treatments, and received midodrine treatment during June 2017-October 2019 were retrospectively analysed.

RESULTS

In total, 24 patients received a treatment dose of midodrine at 5 mg/day (2.5 mg BID) included in the study. The mean number of syncope was 5.75 ± 2.67 prior to treatment. Following treatment, the mean number of syncope was 0.42 ± 0.89. It was observed that syncope episodes did not recur in 17 patients, but it recurred in 4 out of 7 patients in the first 3 months of the treatment and did not recur in the following months. The episodes improved in two patients with an increase in the treatment dose, but the syncope episodes continued in only one patient.

CONCLUSION

It was concluded that midodrine treatment was effective and safe in adolescents with recurrent vasovagal syncope.

European Resuscitation Council Guidelines 2021: First aid

The European Resuscitation Council has produced these first aid guidelines, which are based on the 2020 International Consensus on Cardiopulmonary Resuscitation Science with Treatment Recommendations. The topics include the first aid management of emergency medicine and trauma. For medical emergencies the following content is covered: recovery position, optimal positioning for shock, bronchodilator administration for asthma, recognition of stroke, early aspirin for chest pain, second dose of adrenaline for anaphylaxis, management of hypoglycaemia, oral rehydration solutions for treating exertion-related dehydration, management of heat stroke by cooling, supplemental oxygen in acute stroke, and presyncope. For trauma related emergencies the following topics are covered: control of life-threatening bleeding, management of open chest wounds, cervical spine motion restriction and stabilisation, recognition of concussion, cooling of thermal burns, dental avulsion, compression wrap for closed extremity joint injuries, straightening an angulated fracture, and eye injury from chemical exposure.

Recommendations for tilt table testing and other provocative cardiovascular autonomic tests in conditions that may cause transient loss of consciousness : Consensus statement of the European Federation of Autonomic Societies (EFAS) endorsed by the American Autonomic Society (AAS) and the European Academy of Neurology (EAN)

An expert committee was formed to reach consensus on the use of Tilt Table Testing (TTT) in the diagnosis of disorders that may cause transient loss of consciousness (TLOC) and to outline when other provocative cardiovascular autonomic tests are needed. While TTT adds to history taking, it cannot be a substitute for it. An abnormal TTT result is most meaningful if the provoked event is recognised by patients or eyewitnesses as similar to spontaneous ones. The minimum requirements to perform TTT are a tilt table, a continuous beat-to-beat blood pressure monitor, at least one ECG lead, protocols for the indications stated below and trained staff. This basic equipment lends itself to perform (1) additional provocation tests, such as the active standing test carotid sinus massage and autonomic function tests; (2) additional measurements, such as video, EEG, transcranial Doppler, NIRS, end-tidal CO₂ or neuro-endocrine tests; (3) tailor-made provocation procedures in those with a specific and consistent trigger of TLOC. TTT and other provocative cardiovascular autonomic tests are indicated if the initial evaluation does not yield a definite or highly likely diagnosis, but raises a suspicion of (1) reflex syncope, (2) the three forms of orthostatic hypotension (OH), i.e. initial, classic and delayed OH, as well as delayed orthostatic blood pressure recovery, (3) postural orthostatic tachycardia syndrome or (4) psychogenic pseudosyncope. A therapeutic indication for TTT is to teach patients with reflex syncope and OH to recognise hypotensive symptoms and to perform physical counter manoeuvres.

Recommendations for tilt table testing and other provocative cardiovascular autonomic tests in conditions that may cause transient loss of consciousness : Consensus statement of the European Federation of Autonomic Societies (EFAS) endorsed by the American Autonomic Society (AAS) and the European Academy of Neurology (EAN)

An expert committee was formed to reach consensus on the use of tilt table testing (TTT) in the diagnosis of disorders that may cause transient loss of consciousness (TLOC) and to outline when other provocative cardiovascular autonomic tests are needed. While TTT adds to history taking, it cannot be a substitute for it. An abnormal TTT result is most meaningful if the provoked event is recognised by patients or eyewitnesses as similar to spontaneous events. The minimum requirements to perform TTT are a tilt table, a continuous beat-to-beat blood pressure monitor, at least one ECG lead, protocols for the indications stated below and trained staff. This basic equipment lends itself to the performance of (1) additional provocation tests, such as the active standing test, carotid sinus massage and autonomic function tests; (2) additional measurements, such as video, EEG, transcranial Doppler, NIRS, end-tidal CO₂ or neuro-endocrine tests; and (3) tailor-made provocation procedures in those with a specific and consistent trigger of TLOC. TTT and other provocative cardiovascular autonomic tests are indicated if the initial evaluation does not yield a definite or highly likely diagnosis, but raises a suspicion of (1) reflex syncope, (2) the three forms of orthostatic hypotension (OH), i.e. initial, classic and delayed OH, as well as delayed orthostatic blood pressure recovery, (3) postural orthostatic tachycardia syndrome or (4) psychogenic pseudosyncope. A therapeutic indication for TTT is to teach patients with reflex syncope and OH to recognise hypotensive symptoms and to perform physical counter manoeuvres.

Permanent pacing for recurrent vasovagal syncope: New answers or just more questions?

Vasovagal syncope (VVS) is a clinical condition related to bradycardia (cardioinhibitory response) and/or hypotension (vasodepressor response), likely mediated by parasympathetic overactivity and sympathetic withdrawal. Although clinical presentation is usually related to a self-limited event, frequent episodes or events without prodrome might be debilitating. There are limited medical therapies proven effective in randomized clinical trials. In patients not responsive to standard therapy, permanent pacemaker therapy may be suggested. However, the role of cardiac pacing for the prevention of syncope recurrences remains controversial due to difficulties to exclude potential role of the vasodepressor component during the episode.

Orthostatic hypotension: a pragmatic guide to diagnosis and treatment

Topics for DTB review articles are selected by DTB's editorial board to provide concise overviews of medicines and other treatments to help patients get the best care. Articles include a summary of key points and a brief overview for patients. Articles may also have a series of multiple choice CME questions.

Impact of Yoga on Cardiac Autonomic Function and Arrhythmias

With the expanding integration of complementary and alternative medicine (CAM) practices in conjunction with modern medicine, yoga has quickly risen to being one of the most common CAM practices across the world. Despite widespread use of yoga, limited studies are available, particularly in the setting of dysrhythmia. Preliminary studies demonstrate promising results from integration of yoga as an adjunct to medical therapy for management of dysrhythmias. In this review, we discuss the role of autonomic nervous system in cardiac arrhythmia,interaction of yoga with autonomic tone and its subsequent impact on these disease states. The role of yoga in specific disease states, and potential future direction for studies assessing the role of yoga in dysrhythmia.

Non-Pharmacological and Pharmacological Management of Cardiac Dysautonomia Syndromes

Vasovagal syncope, postural orthostatic tachycardia syndrome, and inappropriate sinus tachycardia comprise a heterogenous group of common autonomic disorders that are associated with significant symptoms that impair quality of life. Clinical management of these disorders should prioritize conservative non-pharmacological therapies and consider incorporating pharmacological agents for recurrences. The selection and titration of medications may be complicated by the occurrence of potentially overlapping pathophysiological variants, differences in specific clinical presentations, and commonly associated comorbidities. However, with appropriate long-term management and specialist input, most patients note both symptomatic improvement and functional restoration over time.

The Differences in the Diagnostic Profile in Children with Vasovagal Syncope between the Result of Head-Up Tilt Table Test

(1) Background: The features characterizing vasovagal syncope (VVS) are an important factor in the correct evaluation of diagnostic risk stratification in children and adolescents. The aim of the study was to determine the value of identifying the clinical characteristics in children with VVS. (2) Methods: We made a retrospective analysis of the medical records of 109 children with diagnosed VVS. We investigated the specific characteristics of syncope in children with VVS including the positive VVS (+) and negative VVS (−) result of the Head-Up Tilt Table Test (HUTT). (3) Results: We did not observe significant differences in the prodromal symptoms of VVS with HUTT response. In addition to typical prodromal symptoms, no difference in statistically reported palpitations (35/109 or 32.1%) and chest discomfort (27/109 or 27.7%) were recorded. Fear–pain–stress emotions as circumstances of syncope were more often reported by children with a negative HUTT (p = 0.02). Cramps–contractures (p = 0.016) and speech disorders (p = 0.038) were significantly higher in the group with negative HUTT. (4) Conclusions: There is a close relationship in the diagnostic profile between the negative and positive results of head-up tilt table test in children with vasovagal syncope.

Todd's paresis following vasovagal syncope provoked by tilt-table testing

A 38-year-old woman presented with a history of recurrent episodes of transient loss of consciousness (TLOC) with seizure-like activity and post-TLOC left sided paresis. Electroencephalogram and MRI of the brain were normal, and events were not controlled by anti-convulsant therapy. Tilt testing produced reflex mixed pattern vasovagal syncope, with exact symptom reproduction, including bilateral upper and lower limb myoclonic movements and post-TLOC left hemiparesis that persisted for 27 min. A witness for the tilt event confirmed reproduction of patients 'typical' TLOC event. Syncope is the most frequent cause of TLOC. Myoclonic movements during syncope are not uncommon and can be misdiagnosed as epilepsy. It is rare to experience paresis after syncope, which in this case, lead to misdiagnosis and unnecessary anti-convulsant treatment.

Video education to improve clinical skills in the prevention of and response to vasovagal syncopal episodes

Background

Objective

Methods

Results

Conclusion

A case report of one vasovagal syncope patient with third-degree atrioventricular block caused by SCN5A gene mutation and literature review

BACKGROUND

Vasovagal syncope (VVS) is common in children and significantly affects their quality of life. To our knowledge, this the first case report of SCN5A gene mutation associated with VVS and third-degree atrioventricular block (atrioventricular block, AVB), which could help pediatricians aware that VVS is not always a benign condition and help to identify VVS children at the risk of sudden death.

CASE PRESENTATION

A twelve-year-old male child was admitted to Beijing Children's Hospital of Capital Medical University for chest tightness for 9 days and syncope in July 2018. The child was diagnosed as VVS with third-degree AVB after complete investagations. A heterozygous mutation in the exon coding region of the SCN5A gene, C. 5851G > T (coding region 5551 nucleotide changed from G to T), was detected in the peripheral blood of the child. Electrophysiological examination and modified vagal ganglion radiofrequency ablation were performed in the child. The ECG playback was normal on the second day after operation. Holter showed no abnormality and no chest tightness or syncope occurred after 3 months and 1 year follow-up.

CONCLUSIONS

Our case report firstly reported that SCN5A mutation contributed to the pathogenesis of VVS with third-degree AVB. Vagal ganglion modified ablation have obtained good therapeutic effect. Gene analysis was of great value to the accurate diagnosis and treatment of VVS children.

Neuro-arrhythmology: a challenging field of action and research: a review from the Task Force of Neuro-arrhythmology of Italian Association of Arrhythmias and Cardiac Pacing

: There is a growing interest in the study of the mechanisms of heart and brain interactions with the aim to improve the management of high-impact cardiac rhythm disorders, first of all atrial fibrillation. However, there are several topics to which the scientific interests of cardiologists and neurologists converge constituting the basis for enhancing the development of neuro-arrhythmology. This multidisciplinary field should cover a wide spectrum of diseases, even beyond the classical framework corresponding to stroke and atrial fibrillation and include the complex issues of seizures as well as loss of consciousness and syncope. The implications of a more focused interaction between neurologists and cardiologists in the field of neuro-arrhythmology should include in perspective the institution of research networks specifically devoted to investigate 'from bench to bedside' the complex pathophysiological links of the abovementioned diseases, with involvement of scientists in the field of biochemistry, genetics, molecular medicine, physiology, pathology and bioengineering. An investment in the field could have important implications in the perspectives of a more personalized approach to patients and diseases, in the context of 'precision'medicine. Large datasets and electronic medical records, with the approach typical of 'big data' could enhance the possibility of new findings with potentially important clinical implications. Finally, the interaction between neurologists and cardiologists involved in arrythmia management should have some organizational implications, with new models of healthcare delivery based on multidisciplinary assistance, similarly to that applied in the case of syncope units.

[Lifestyle Modification as a Method of Treatment of Vasovagal Syncope]

Vasovagal syncope is the most common cause for loss of consciousness. The need for treatment of this condition is warranted by impaired quality of life and a risk of trauma due to the fall. At present, there are no medications with proven preventive effectiveness for vasovagal syncope as demonstrated by large randomized, placebo-controlled studies.  At the same time, information about the pathogenesis of vasovagal reaction and provoking factors allows effective use of non-drug methods (such as patient education, physical exercise, maneuvers) in the management of patients with vasovagal syncope.

Intermittent Calf Compression Delays the Onset of Presyncope in Young Healthy Individuals

Orthostatic fluid shifts reduce the effective circulating volume and thus contribute to syncope susceptibility. Recurrent syncope has a devastating impact on quality of life and is challenging to manage effectively. To blunt orthostatic fluid shifts, static calf compression garments are often prescribed to patients with syncope, but have questionable efficacy. Intermittent calf compression, which mimics the skeletal muscle pump to minimize pooling and filtration, holds promise for the management of syncope. We aimed to evaluate the effectiveness of intermittent calf compression for increasing orthostatic tolerance (OT; time to presyncope). We conducted a randomized single-blind crossover study, in which participants (n = 21) underwent three graded 60° head-up-tilt tests to presyncope with combined lower body negative pressure on separate days. Low frequency intermittent calf compression (ICLF; 4 s on and 11 s off) at 0-30 and 0-60 mmHg was applied during two tests and compared to a placebo condition where the garment was fitted, but no compression applied. We measured continuous leg circumference changes (strain gauge plethysmography), cardiovascular responses (finger plethysmography; Finometer Pro), end tidal gases (nasal cannula), and cerebral blood flow velocity (CBFv, transcranial Doppler). The 0-60 mmHg ICLF increased OT (33 ± 2.2 min) compared to both placebo (26 ± 2.4 min; p < 0.001) and 0-30 mmHg ICLF (25 ± 2.7 min; p < 0.001). Throughout testing 0-60 mmHg ICLF reduced orthostatic fluid shifts compared to both placebo and 0-30 mmHg ICLF (p < 0.001), with an associated improvement in stroke volume (p < 0.001), allowing blood pressure to be maintained at a reduced heart rate (p < 0.001). In addition, CBFv was higher with 0-60 mmHg ICLF than 0-30 mmHg ICLF and placebo (p < 0.001). Intermittent calf compression is a promising novel intervention for the management of orthostatic intolerance, which may provide affected individuals renewed independence and improved quality of life.

Diagnostic and therapeutic approach to cardioinhibitory reflex syncope: A complex and controversial issue

Syncope is defined as a transient loss of consciousness due to global cerebral hypoperfusion and is one of the leading causes of emergency department admission. The initial approach should focus on excluding non-syncopal causes for loss of consciousness and risk stratification for cardiac cause, in order to ensure an appropriate etiological investigation and therapeutic approach. Vasovagal syncope (VVS), the most common type of syncope, should be assumed once other causes are excluded. Pathophysiologically, the vasovagal reflex is the result of a paradoxical autonomic response, leading to hypotension and/or bradycardia. VVS has not been shown to affect mortality, but morbidity may be considerable in those with recurrent syncopal episodes. The management of VVS includes both non-pharmacological and pharmacological measures that act on various levels of the reflex arc that triggers the syncopal episode. However, most are of uncertain benefit given the scarcity of high-quality supporting evidence. Pacemaker therapy may be considered in recurrent refractory cardioinhibitory reflex syncope, for which it is currently considered a robust intervention, as noted in the European guidelines. Non-randomized and unblinded studies have shown a potential benefit of pacing in recurrent VVS, but double-blinded randomized controlled trials have not consistently demonstrated positive results. We performed a comprehensive review of the current literature and recent advances in cardiac pacing and pacing algorithms in VVS, and discuss the diagnostic and therapeutic approach to the complex patient with recurrent VVS and reduced quality of life.

Hemodynamic differences in isometric counter-pressure maneuvers and their efficacy in vasovagal syncope

Background

Isometric counter-pressure maneuvers (ICM) were proposed as first-line treatment in patients with vasovagal syncope (VVS). The aim was to study hemodynamic mechanisms and effectiveness of ICM in prevention of head-up tilt (HUT)-induced and spontaneous VVS.

Methods

In 38 patients with VVS (9 men, 28 women, mean age 35.82 ± 15.2 years), following ICM were performed—squatting (SQ), leg crossing with muscle tensing (LCMT), whole-body tensing (WBT), heel raises (HeR), toe extension (TE), and unilateral handgrip (HG). Hemodynamic parameters were recorded during ICM using photopletysmographic principle: blood pressure, heart rate, cardiac output, stroke volume, and total peripheral resistance. Clinical efficacy of ICM was assessed during HUT-induced presyncope. The recurrence of syncope and quality of life were also evaluated during 26 ± 7 month follow-up period.

Results

All maneuvers increased mean arterial pressure. The hemodynamic background of ICM was not uniform. In most ICM (LCMT, WBT, HeR, and TE), an increase in CO due to simultaneous increase in HR and SV was observed. In SQ, the underlying mechanism was augmentation of stroke volume by increased venous return. In unilateral HG, a rise in peripheral resistance was the principal mechanism. ICM were able to prevent syncope in 47% of patients during HUT-induced presyncope and in 71% of patients during spontaneous presyncope. Quality of life improved in all patients.

Conclusions

ICM increase blood pressure by variable hemodynamic mechanisms. ICM effectively counteract the HUT-induced and spontaneous vasovagal syncope and improve quality of life.