Syncope and the risk of sudden cardiac death: Evaluation, management, and prevention

The syncope core management process in the emergency department: a consensus statement of the EUSEM syncope group

The European Society of Cardiology issued updated syncope guidelines in 2018 which included recommendations for managing syncope in the emergency department (ED) setting. However, these guidelines lack detailed process-oriented instructions regarding the fact that ED syncope patients initially present with a transient loss of consciousness (TLOC), which can have a broad spectrum of causes. This study aims to establish a European consensus on the general process of the workup and care for patients with suspected syncope and provides rules for sufficient and systematic management of the broad group of syncope (initially presenting as TLOC) patients in the ED. A variety of European diagnostic and therapeutic standards for syncope patients were reviewed and summarized in three rounds of a modified Delphi process by the European Society for Emergency Medicine syncope group. Based on a consensus statement, a detailed process pathway is created. The primary outcome of this work is the presentation of a universal process pathway for the structured management of syncope patients in European EDs. The here presented extended event process chain (eEPC) summarizes and homogenizes the process management of European ED syncope patients. Additionally, an exemplary translation of the eEPC into a practice-based flowchart algorithm, which can be used as an example for practical use in the ED, is provided in this work. Syncope patients, initially presenting with TLOC, are common and pose challenges in the ED. Despite variations in process management across Europe, the development of a universally applicable syncope eEPC in the ED was successfully achieved. Key features of the consensus and eEPC include ruling out life-threatening causes, distinguishing syncope from nonsyncopal TLOCs, employing syncope risk stratification categories and based on this, making informed decisions regarding admission or discharge.

Development and Validation of a Novel Predictive Model for the Early Differentiation of Cardiac and Non-Cardiac Syncope

Background

The diagnosis of cardiac syncope remains a challenge. This study sought to develop and validate a diagnostic model for the early identification of individuals likely to have a cardiac cause.

Methods

877 syncope patients with a determined cause were retrospectively enrolled at a tertiary heart center. They were randomly divided into the training set and validation set at a 7:3 ratio. We analyzed the demographic information, medical history, laboratory tests, electrocardiogram, and echocardiogram by the least absolute shrinkage and selection operator (LASSO) regression for selection of key features. Then a multivariable logistic regression analysis was performed to identify independent predictors and construct a diagnostic model. The receiver operating characteristic curves, area under the curve (AUC), calibration curves, and decision curve analysis were used to evaluate the predictive accuracy and clinical value of this nomogram.

Results

Five independent predictors for cardiac syncope were selected: BMI (OR 1.088; 95% CI 1.022-1.158; P =0.008), chest symptoms preceding syncope (OR 5.251; 95% CI 3.326-8.288; P <0.001), logarithmic NT-proBNP (OR 1.463; 95% CI 1.240-1.727; P <0.001), left ventricular ejection fraction (OR 0.940; 95% CI 0.908-0.973; P <0.001), and abnormal electrocardiogram (OR 6.171; 95% CI 3.966-9.600; P <0.001). Subsequently, a nomogram based on a multivariate logistic regression model was developed and validated, yielding AUC of 0.873 (95% CI 0.845-0.902) and 0.856 (95% CI 0.809-0.903), respectively. The calibration curves showcased the nomogram's reasonable calibration, and the decision curve analysis demonstrated good clinical utility.

Conclusion

A diagnostic tool providing individualized probability predictions for cardiac syncope was developed and validated, which may potentially serve as an effective tool to facilitate early identification of such patients.

Do serial troponins predict the need for cardiac evaluation in trauma patients after ground-level fall?

Purpose

Troponin T levels are routinely checked in trauma patients after experiencing a ground-level fall to identify potential cardiac causes of syncope. An elevated initial troponin prompts serial testing until the level peaks. However, the high sensitivity of the test may lead to repeat testing that is of little clinical value. Here, we examine the role of serial troponins in predicting the need for further cardiac workup in trauma patients after sustaining a fall.

Methods

Retrospective review of all adult trauma activations for ground-level fall from January 1, 2021 to December 31, 2021 in patients who were hemodynamically and neurologically normal at presentation. Outcomes evaluated included need for cardiology consult, admission to cardiology service, outpatient cardiology follow-up, cardiology intervention and in-hospital mortality.

Results

There were 1555 trauma activations for ground-level fall in the study period. The cohort included 560 patients evaluated for a possible syncopal fall, hemodynamically stable, Glasgow Coma Scale score of 15, and with a troponin drawn at presentation. The initial median troponin was 20 ng/L (13-37). Second troponin values were drawn on 58% (median 33 ng/L (22-52)), with 42% of patients having an increase from first to second test. 29% of patients had a third troponin drawn (median 42 ng/L (26-67)). The initial troponin value was significantly associated with undergoing a subsequent echo (p=0.01), cardiology consult (p<0.01), admission for cardiac evaluation (p<0.01), cardiology follow-up (p<0.01), and in-hospital mortality (p=0.01); the initial troponin was not associated with cardiac intervention (p=0.91). An increase from the first to second troponin was not associated with any of outcomes of interest. Analysis was done with cut-off values of 30 ng/L, 50 ng/L, 70 ng/L, and 90 ng/L; a troponin T threshold of 19 ng/L was significant for cardiology consult (p=0.01) and cardiology follow-up (p=0.04). When the threshold was increased to 50 ng/L, it was also significant for admission for cardiac issue (p<0.01). When the threshold was increased to 90 ng/L, it was significant for the same three outcomes and in-hospital mortality (p=0.04).

Conclusion

The initial serum troponin has clinical value in identifying underlying cardiac disease in patients who present after ground-level fall; however, that serial testing is likely of little value. Further, using a cut-off of >50 ng/L as a threshold for further clinical evaluation would improve the utility of the test and likely reduce unnecessary hospital stays and costs for otherwise healthy patients.

Level of evidence

Level III.

Comparison of continuous 24-hour and 14-day ECG monitoring for the detection of cardiac arrhythmias in patients with ischemic stroke or syncope

BACKGROUND

Previous studies show that using 12-lead electrocardiogram (ECG) or 24-h ECG monitor for the detection of cardiac arrhythmia events in patients with stroke or syncope is ineffective.

HYPOTHESIS

The 14-day continuous ECG patch has higher detection rates of arrhythmias compared with conventional 24-h ECG monitoring in patients with ischemic stroke or syncope.

METHODS

This cross-sectional study of patients with newly diagnosed ischemic stroke or syncope received a 24-h ECG monitoring and 14-day continuous cardiac monitoring patch and the arrhythmia events were measured.

RESULTS

This study enrolled 83 patients with ischemic stroke or syncope. The detection rate of composite cardiac arrhythmias was significantly higher for the 14-day ECG patch than 24-h Holter monitor (69.9% vs. 21.7%, p = .006). In patients with ischemic stroke, the detection rates of cardiac arrhythmias were 63.4% for supraventricular tachycardia (SVT), 7% for ventricular tachycardia (VT), 5.6% for atrial fibrillation (AF), 4.2% for atrioventricular block (AVB), and 1.4% for pause by 14-day ECG patch, respectively. The significant difference in arrhythmic detection rates were found for SVT (45.8%), AF (6%), pause (1.2%), AVB (2.4%), and VT (9.6%) by 14-day ECG patch but not by 24-h Holter monitor in patients with ischemic stroke or syncope.

CONCLUSIONS

A 14-day ECG patch can be used on patients with ischemic stroke or syncope for the early detection of AF or other cardiac arrhythmia events. The patch can be helpful for physicians in planning medical or mechanical interventions of patients with ischemic stroke and occult AF.

Recent Advances and Future Directions in Syncope Management: A Comprehensive Narrative Review

Syncope is a highly prevalent clinical condition characterized by a rapid, complete, and brief loss of consciousness, followed by full recovery caused by cerebral hypoperfusion. This symptom carries significance, as its potential underlying causes may involve the heart, blood pressure, or brain, leading to a spectrum of consequences, from sudden death to compromised quality of life. Various factors contribute to syncope, and adhering to a precise diagnostic pathway can enhance diagnostic accuracy and treatment effectiveness. A standardized initial assessment, risk stratification, and appropriate test identification facilitate determining the underlying cause in the majority of cases. New technologies, including artificial intelligence and smart devices, may have the potential to reshape syncope management into a proactive, personalized, and data-centric model, ultimately enhancing patient outcomes and quality of life. This review addresses key aspects of syncope management, including pathogenesis, current diagnostic testing options, treatments, and considerations in the geriatric population.

The influence of extreme thermal stress on the physiological and psychological characteristics of young women who sporadically use the sauna: practical implications for the safe use of the sauna

Background

Many individuals who use the sauna at a temperature of 120°C of higher are not aware of the negative consequences of extreme thermal stress. Despite extensive research into sauna use, the impact of extreme thermal stress on the physiological and psychological characteristics of sauna users have not been examined to date.

Aim

The aim was to determine the effect of 20 min sauna sessions with a temperature of 80°C and 120°C on the physiological and psychological characteristics of women who sporadically visit the sauna.

Methods

The study was conducted on 22 full-time female university students. Physical activity (PA) levels were evaluated with the Polish short version of the International Physical Activity Questionnaire (IPAQ). Anthropometric characteristics were measured before the first sauna session by the InBody270 body composition analyzer. Physiological parameters, including heart, energy expenditure, physical effort, and blood pressure (systolic blood pressure - SBP, and diastolic blood pressure - DBP), were assessed indirectly using Polar V800 heart rate monitors and the Omron M6 Comfort blood pressure monitor. The participants' wellbeing was assessed with the Profile of Mood States (POMS) questionnaire. The presence of significant correlations between heat exhaustion and heat stress variables and syncope during the second sauna session was examined with the use of classification and regression trees (CRT) and the cross-validation technique.

Results

Twenty-minute sauna sessions with a temperature of 80°C and 120°C induced a significant (p < 0.001) decrease in the values of SBP (excluding the temperature of 120°C), DBP, and body mass, as well as a significant increase in HR and forehead temperature. Exposure to a temperature of 80°C led to a significant (p < 0.001) increase in vigor with a simultaneous decrease in tension, depression, anger, fatigue, and confusion. In turn, sauna bathing at a temperature of 120°C had an opposite effect on the above mood parameters. Vomiting and confusion were the main predictors of syncope that occurred in some of the surveyed women.

Conclusion

Excessive air temperature can induce symptoms characteristic of heat exhaustion and heat stress nausea, heavy sweating, fast weak or strong HR, high body temperature, and confusion. Therefore, sauna bathing at a temperature of 80°C can be recommended to women who sporadically use the sauna, whereas exposure to a temperature of 120°C is not advised in this group of sauna users. The present findings provide highly valuable inputs for managing wellness and SPA centers.

Sports Heart Monitors as Reliable Diagnostic Tools for Training Control and Detecting Arrhythmias in Professional and Leisure-Time Endurance Athletes: An Expert Consensus Statement

There are countless types of portable heart rate monitoring medical devices used variously by leisure-time exercisers, professional athletes, and chronically ill patients. Almost all the currently used heart rate monitors are capable of detecting arrhythmias, but this feature is not widely known or used among their millions of consumers. The aims of this paper were as follows: (1) to analyze the currently available sports heart rate monitors and assess their advantages and disadvantage in terms of heart rate and rhythm monitoring in endurance athletes; (2) to discuss what types of currently available commercial heart rate monitors are most convenient/adjustable to the needs of different consumers (including occasionally physically active adults and cardiac patients), bearing in mind the potential health risks, especially heart rhythm disturbances connected with endurance training; (3) to suggest a set of "optimal" design features for next-generation smart wearable devices based on the consensus opinion of an expert panel of athletes, coaches, and sports medicine doctors. Ninety-two experts aged 20 years and over, involved in endurance sports on a daily basis, were invited to participate in consensus-building discussions, including 56 long-distance runners, 18 cyclists, nine coaches, and nine physicians (sports medicine specialists, cardiologists, and family medicine doctors). The overall consensus endorsed by these experts indicates that the "optimal" sports heart rate monitor should be a one-piece device of the smartwatch type (with two or more electrodes), with integrated smartphone features, and able to collect and continually transmit data without exhibiting artifacts. It should continuously record at least a single-lead electrocardiography, send an alert after an unexpected fall, be of reasonable weight, come at an affordable price, and be user friendly.

Comparison of syncope risk scores in predicting the prognosis of patients presenting to the emergency department with syncope

BACKGROUND

Various scores have been derived for the assessment of syncope patients in the emergency department (ED).

AIM

We aimed to compare the effectiveness of Canadian Syncope Risk Scores (CSRS), San Francisco Syncope Rules (SFSR), and Osservatorio Epidemiologico sulla Sincope nel Lazio (OESIL) risk scores in predicting the risk of major adverse cardiac events (MACE) and mortality among syncope patients within 30 days of the initial ED visit.

METHODS

We performed a prospective, observational case series study of adults (≥ 18 years) with unexplained syncope/near-syncope who presented to ED. Demographic characteristics of the patients and clinical and laboratory data were recorded in the standard data collection form of the study. Our primary outcome was a 30-day mortality.

RESULTS

A total of 421 patients (mean age 50.9 ± 20.8, 51.5% male) were enrolled. The rate of MACE development in the 30-day follow-up of the patients was 12.8% (n = 54). While 20.2% (n = 85) of the patients were hospitalized, two of the patients died in the emergency room and the 30-day mortality was 5.5% (n = 23). CSRS was found to have the highest predictive power of mortality (AUC: 0.869, 95% CI 0.799-0.939, p < 0.001). If the cut-off value of CSRS was 0.5, the sensitivity was found to be 82.6% and the specificity was 81.9%. Also CSRS (OR: 1.402, 95% CI: 1.053-1.867, p = 0.021) was found to be an independent predictor of the 30-day mortality.

CONCLUSION

The CSRS may be used as a safety risk score for a 30-day risk of MACE and mortality after discharge from the emergency department.

Diagnostic accuracy of high sensitivity troponin and association of electrocardiogram findings for mortality in syncope patients: A retrospective cohort study

High-sensitivity cardiac troponin-T (hs-cTnT) and electrocardiogram (ECG) are commonly ordered in daily practice in emergency medicine but their value on long term mortality in syncope patients is unclear. Our aim is to determine the diagnostic accuracy of hs-cTnT and association of ECG findings for 1-year mortality in patients presenting with syncope. In this retrospective cohort study, we included patients presenting with syncope to the emergency department (ED) between May 2020 and May 2021. Patient demographics, vital parameters on admission, ECG findings, hs-cTnT level at admission and 1-year mortality status were recorded. The study included 417 patients (62.4% women) with a mean age of 41.51 (standard deviation [SD] 17.1), 21 of whom were deceased within 1 year after syncope attack (5%). Patients with an abnormal QTc, T-Axis or frontal QRS-T angle had significantly higher 1-year mortality (OR: 9.26, 95% CI: 1.64-52.31; OR: 5.82, 95% CI: 1.69-20.1; 4.94, 95% CI: 1.45-16.84, respectively). The hs-cTnT level was 21.92 pg/mL (95% CI: 3.35-40.51 pg/mL) higher in the mortality group (P = .023). An abnormal QTc, T-Axis and frontal QRS-T angle are associated with a higher 1-year mortality rate and hs-cTnT has good diagnostic accuracy in detecting 1-year mortality for patients presenting with syncope.

Investigation of High-Risk Electrocardiographic Markers as Predictors of Major Arrhythmic Events in Brugada Syndrome: A Systematic Review and Meta-analysis

INTRODUCTION

Numerous studies have demonstrated that a type I Brugada electrocardiographic (ECG) pattern, history of syncope, prior sudden cardiac arrest, and previously documented ventricular tachyarrhythmias are still insufficient to stratify the risk of sudden cardiac death in Brugada syndrome (BrS). Several auxiliary risk stratification parameters are pursued to yield a better prognostic model. Our aim was to assess the association between several ECG markers (wide QRS, fragmented QRS, S-wave in lead I, aVR sign, early repolarization pattern in inferolateral leads, and repolarization dispersion pattern) with the risk of developing poor outcomes in BrS.

METHODS

A systematic literature search from several databases was conducted from database inception until August 17^th, 2022. Studies were eligible if it investigated the relationship between the ECG markers with the likelihood of acquiring major arrhythmic events (MAE).

RESULTS

This meta-analysis comprised 27 studies with a total of 6552 participants. Our study revealed that wide QRS, fragmented QRS, S-wave in lead I, aVR sign, early repolarization pattern in inferolateral leads, and repolarization dispersion ECG pattern were associated with the incremental risk of syncope, ventricular tachyarrhythmias, implantable cardioverter-defibrillator shock, and sudden cardiac death in the future, with the risk ratios ranging from 1.41 to 2.00. Moreover, diagnostic test accuracy meta-analysis indicated that the repolarization dispersion ECG pattern had the highest overall area under curve (AUC) value amid other ECG markers regarding our outcomes of interest.

CONCLUSION

A multivariable risk assessment approach based on the prior mentioned ECG markers potentially improves the current risk stratification models in BrS patients.

Trauma and syncope: looking beyond the injury

Background

42% of the population experience syncope by the age of 70, accounting for up to 6% of hospital admissions that frequently present as falls. The etiologies of some falls are benign, and others, such as cardiac syncope, are associated with a greater mortality and must be identified.

Methods

This review article aims to bridge the literature gap by providing a comprehensive practice review and critical summary of the current syncope guidance relating to the trauma patient.

Results

The National Institute for Health and Care Excellence, the American College of Cardiology, and European Society of Cardiology published syncope risk stratification guidance. The inclusion of certain high-risk features represented in all three guidelines suggests their significance to identify cardiac syncope including heart failure, abnormal vital signs, syncope during exercise with little to no prodrome, family history of sudden cardiac death, and ECG abnormalities. Of 11 syncope risk stratification scoring systems based on these guidelines, only 2 are externally validated in the emergency department, neither of which are validated for major trauma use. Adherence to thorough history-taking, examination, orthostatic blood pressure recording, and an ECG can diagnose the cause of syncope in up to 50% of patients. ECG findings are 95% to 98% sensitive in the detection of serious adverse outcomes after cardiac syncope and should form part of a standardized syncope trauma assessment. Routine blood testing in trauma is often performed despite evidence that it is neither useful nor cost effective, where the screening of cardiac enzymes and D-dimer rarely influences management.

Discussion

In the absence of a gold-standard clinical test to identify the cause of a syncopal episode, standardized syncope guidelines as described in this review could be incorporated into trauma protocols to analyze high-risk etiologies, improve diagnostic accuracy, reduce unnecessary investigations, and develop an effective and safer management strategy.

Evaluation of the Patient With Paroxysmal Spells Mimicking Epileptic Seizures

BACKGROUND

The diagnostic issue of paroxysmal spells, including epileptic seizure (ES) mimics, is one that neurologists frequently encounter. This review provides an up-to-date overview of the most common causes of ES mimics encountered in the outpatient setting.

REVIEW SUMMARY

Paroxysmal spells are characterized by changes in awareness, attention, perception, or abnormal movements. These can be broadly classified as ES and nonepileptic spells (NES). NES mimics ES but are distinguished by their symptomatology and lack of epileptiform activity on electroencephalography. NES may have psychological or physiological underpinnings. Psychogenic non-ES are the most common mimics of ES. Physiological causes of NES include syncope, cerebrovascular, movement, and sleep-related disorders.

CONCLUSIONS

Distinguishing NES from ES at times may be challenging even to the most experienced clinicians. However, detailed history with an emphasis on the clinical clues, including taking a moment-by-moment history of the event from the patient and observers and physical examination, helps create an appropriate differential diagnosis to guide further diagnostic testing. An accurate diagnosis of NES prevents iatrogenic harm, including unnecessary exposure to antiseizure medications and overuse of health care resources. It also allows for the correct specialist referral and appropriate treatment.

Cardiac and Vascular Causes of Syncope and Atherosclerosis

PURPOSE OF REVIEW

Among the most common causes of cardiac syncope are arrhythmias and ischemic heart disease, both of which can coexist. The purpose of this review is to discuss the main causes of cardiac and vascular syncope related to atherosclerosis, its epidemiological and clinical aspects, warning signs, and initial approach.

RECENT FINDINGS

Cardiac syncope may have a frequency of up to 34% in elderly people. Atherosclerosis-related causes of cardiac and vascular syncope may be due to cardiac arrhythmia and/or structural impairment of the heart or arteries. Late ventricular tachycardia and late-onset high-grade atrioventricular block associated with myocardial ischemia may occur with syncope, which is related to higher mortality. Besides ventricular dysfunction, concentric remodeling is also a prognostic factor. In calcific degenerative aortic stenosis, syncope carries a worse prognosis than the other cardinal signs. Cardiac syncope has a high recurrence and mortality rate. There are red flag alerts that must be considered in risk stratification.

Frailty on the acute medical take

Frailty is a prevalent condition in urgent care settings associated with an increased risk of adverse events. Frailty commonly presents on the acute medical take in the form of geriatric syndromes, which include falls, delirium and immobility. Comprehensive geriatric assessment is the evidence-based holistic approach to assessing and managing people with frailty. This multidimensional and interdisciplinary process is generally specialist led, however, acute medical teams can make important contributions through early identification and grading of frailty, and proactive management of geriatric syndromes.

Assessment of Canadian Syncope Risk Score in the prediction of outcomes of patients with syncope at the Emergency Department of Suez Canal University: STROBE compliant

Syncope is a temporary loss of consciousness usually related to insufficient blood flow to the brain. It's also called fainting or "passing out." Syncope is responsible for 3% to 5% of emergency department visits, with a hospitalization rate in about 40% of cases, with an average stay of 5.5 days. The Canadian Syncope Risk Score showed good discrimination and calibration for 30-day risk of serious adverse events after disposition from the emergency department.The aim was to assess Canadian Syncope Risk Score in predicting outcomes and mortality at the emergency department of Suez Canal University Hospitals.A prospective observational cohort study was carried out in emergency department in Suez Canal University Hospital. After approval by the Ethical and Research Committee of Faculty of Medicine, Suez Canal University, 60 patients with syncope attending to emergency department were included to this study. All included participants were assessed by history taking and they also assessed by the Canadian Syncope Risk Score.The Canadian Syncope Risk Score's mean of the study group was 4.9 and the range of the scores was from -2 to 11. The mean of the percentage of risk of serious events at 30 days in the study group was 29.17% and it ranged from 0.7% to 83.6%.There was a statistically significant difference between means Canadian Syncope Risk Score's score regarding complication occurrence. Cases which showed complications had a mean score of 7.33 compared to a mean score of 1.25 in case of no complication occurrence P-value <.001. At a cut-off point of more than 3 for the Canadian Syncope Risk Score's, sensitivity of that score in complication's occurrence prediction was 100% and the specificity was 87.5% P-value <.001.The Canadian Syncope Risk Score's is strong predictor for risk of serious adverse events and a good indicator for admission, with 100% sensitivity and 87.5% specificity at cut off point more than 3.

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.

Appropriate use of transthoracic echocardiography in the investigation of general medicine patients presenting with syncope or presyncope

STUDY PURPOSE

Routine transthoracic echocardiography (TTE) in patients with syncope or presyncope is resource-intensive. We assessed if risk thresholds defined by a validated risk score may identify patients at low risk of cardiac abnormality in whom TTE is unnecessary.

STUDY DESIGN

We conducted a retrospective study of all general medicine patients with syncope/presyncope presenting to a tertiary hospital between July 2016 and September 2020 and who underwent TTE. The Canadian Syncope Risk Score (CSRS) was used to categorise patients as low to very low risk (score -3 to 0) or moderate to high risk (score ≥1) for serious adverse events at 30 days. A cut-point of 0 was used to calculate the sensitivity, specificity, positive and negative predictive values (PPV and NPV) for CSRS and the odds ratio (OR) of a clinically significant finding on TTE in patients with CSRS ≥1 compared with all patients.

RESULTS

Among 157 patients, the CSRS categorised 69 (44%) as very low to low risk in whom TTE was normal. In 88 patients deemed moderate to high risk, TTE detected a cardiac abnormality in 24 (27%). A CSRS ≥1 yielded a sensitivity of 100% (95% CI 85.7% to 100%), specificity of 51.1% (95% CI 42.3% to 59.8%), PPV of 26.5% (95% CI 26.3% to 30.1%) and NPV of 100% (95% CI 92.5% to 100%) for cardiac abnormalities and doubled the odds of an abnormality (OR=2.05, 95% CI 1.08 to 3.87, p=0.028).

CONCLUSION

In general medicine patients with syncope/presyncope, using the CSRS to stratify risk of a cardiac abnormality on TTE can almost halve TTE use.

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.

Current best practices in emergency evaluation and management of syncope

ABSTRACT

Syncope is a common medical presentation that can cost the US healthcare system up to $2.4 billion dollars annually. Much of this cost can be mitigated with proper evaluation and management in the urgent care setting, as well as appropriate use of a risk stratification system.

Cardiac Biomarkers and Autoantibodies in Endurance Athletes: Potential Similarities with Arrhythmogenic Cardiomyopathy Pathogenic Mechanisms

The “Extreme Exercise Hypothesis” states that when individuals perform training beyond the ideal exercise dose, a decline in the beneficial effects of physical activity occurs. This is due to significant changes in myocardial structure and function, such as hemodynamic alterations, cardiac chamber enlargement and hypertrophy, myocardial inflammation, oxidative stress, fibrosis, and conduction changes. In addition, an increased amount of circulating biomarkers of exercise-induced damage has been reported. Although these changes are often reversible, long-lasting cardiac damage may develop after years of intense physical exercise. Since several features of the athlete’s heart overlap with arrhythmogenic cardiomyopathy (ACM), the syndrome of “exercise-induced ACM” has been postulated. Thus, the distinction between ACM and the athlete’s heart may be challenging. Recently, an autoimmune mechanism has been discovered in ACM patients linked to their characteristic junctional impairment. Since cardiac junctions are similarly impaired by intense physical activity due to the strong myocardial stretching, we propose in the present work the novel hypothesis of an autoimmune response in endurance athletes. This investigation may deepen the knowledge about the pathological remodeling and relative activated mechanisms induced by intense endurance exercise, potentially improving the early recognition of whom is actually at risk.

Clinical Predictors of Occurrence of Ventricular Tachyarrhythmias in Patients with Reduced Left Ventricle Ejection Fraction. Results of Single-Center Prospective Study

Aim      To evaluate the diagnostic significance of clinical and demographic parameters for predicting a 2-year probability of ventricular tachyarrhythmias (VT) in patients with chronic heart failure and reduced left ventricular ejection fraction (CHFrLVEF).Material and methods  This single-center, prospective cohort study included 175 patients with CHFrLVEF who were implanted with a cardioverter defibrillator (CD). The endpoint was a CD-detected episode of VT. Patients were followed up for 2 years with visits at 3, 12, and 24 months after CD implantation.Results The primary endpoint was observed in 43 (24.4 %) patients at an average of 20.9 months (95 % confidence interval (CI), 20-21.9). The 2-year risk of fatal ventricular arrhythmias increased with detection of unstable VT (one-factor analysis, odds ratio (OR), 4.2; 95 % CI, 1.1-16.5; р=0.041; multifactor analysis, OR, 6.3; 95 % CI, 1.5-26.3; р=0.012) and with ischemic CHFrLVEF origin (one-factor analysis, OR, 2.2; 95 % CI, 1.1-4.5; p=0.021; multifactor analysis, OR, 2.5; 95 % CI, 1.2-5.1; р=0.018). In the presence of any type of atrial fibrillation (AF) in patients with non-ischemic CHFrLVEF, the probability of VT increased threefold (one-factor analysis, OR, 2.97; 95 % CI, 1.02-8.8; р=0.047; multifactor analysis, OR, 3.5; 95 % CI, 1.1-10.9; р=0.032).Conclusion      The presence of ischemic heart disease and unstable VT paroxysms can be included in the number of important clinical predictors of VT in patients with CHFrLVEF. In patients with non-ischemic CHF, the presence of AF is associated with a high risk of VT.

Genetic Determinants and Genotype-Phenotype Correlations in Vietnamese Patients With Dilated Cardiomyopathy

BACKGROUND

Dilated cardiomyopathy (DCM) is an important cause of heart failure and cardiac transplantation. This study determined the prevalence of DCM-associated genes and evaluated the genotype-phenotype correlation in Vietnamese patients.Methods and Results:This study analyzed 58 genes from 230 patients. The study cohort consisted of 64.3% men; age at diagnosis 47.9±13.7 years; familial (10.9%) and sporadic DCM (82.2%). The diagnostic yield was 23.5%, 44.0% in familial and 19.6% in sporadic DCM.TTNtruncating variants (TTNtv) were predominant (46.4%), followed byTPM1,DSP,LMNA,MYBPC3,MYH6,MYH7,DES,TNNT2,ACTC1,ACTN2,BAG3,DMD,FKTN,PLN,TBX5,RBM20,TCAP(2-6%). Familial DCM, genotype-positive andTTNtv-positive patients were younger than those with genotype-negative and sporadic DCM. Genotype-positive patients displayed a decreased systolic blood pressure and left ventricular wall thickness compared to genotype-negative patients. Genotype-positive patients, particularly those withTTNtv, had a family history of DCM, higher left atrial volume index and body mass index, and lower right ventricle-fractional area change than genotype-negative patients. Genotype-positive patients reached the combined outcomes more frequently and at a younger age than genotype-negative patients. Major cardiac events occurred more frequently in patients positive with genes other thanTTNtv.

CONCLUSIONS

The study findings provided an overview of Vietnamese DCM patients' genetic profile and suggested that management of environmental factors may be beneficial for DCM patients.

Frequency of syncope as a presenting symptom in channelopathies diagnosed in childhood. Can the multivariable EGSYS score unmask these children?

Pediatric syncope raises cardiac etiology concern as it might be the first sign of life-threatening arrhythmia syndromes. Our aim was to study the incidence of syncope as the presenting symptom in children with arrhythmia syndromes, and if known, warning signs are helpful to reveal the arrhythmic origin. All data on children with channelopathy was followed by a tertiary pediatric cardiac center between 2000 and 2018 and data were reviewed retrospectively. Forty-eight patients were enrolled, representing long QT syndrome (n = 39), catecholaminergic polymorphic ventricular tachycardia (n = 5), and Brugada syndrome (n = 4). Presenting symptoms were syncope in 13 cases [27%] (including 7 initially mislabeled as epilepsy) and sudden cardiac arrest (SCA) in 9 cases [19%]. In the rest of the group, the concern for arrhythmic etiology was raised by either an abnormal ECG during sports medicine screening (n = 13) [27%] or a positive family history of channelopathy (n = 13) [27%]. None of the patients presenting with SCA had a prior syncopal history. Six patients presenting with syncope and afterward treated with ICD had an appropriate shock. Description of witnessed syncope was available in eight out of thirteen children presenting with syncope. Multivariable EGSYS score suggested cardiac origin (≥ 3 points) in 7 out of 8 (88%) patients.Conclusions: Syncope was a relatively uncommon presenting symptom of channelopathies in this sample and did not always precede sudden cardiac arrests. However, we found that multivariable EGSYS score can identify syncope of arrhythmic origin, raising suspicion for pediatric channelopathies even in patients previously misdiagnosed with epilepsy. What is known: • Cardiac syncope is rare in children but can be the first sign of a potentially fatal primary arrhythmia syndrome and is frequently misdiagnosed as atypical/therapy-resistant epilepsy. • Multivariate EGSYS score is effective to diagnose cardiac syncope in adults. What is new: • Cardiac syncope as a presenting symptom is not common in children with cardiac channelopathies and is not often present before sudden cardiac arrest. • Multivariable EGSYS score might identify cardiac syncope in children with a hereditary and secondary channelopathy.

Association of variants in MYH7, MYBPC3 and TNNT2 with sudden cardiac death-related risk factors in Brazilian patients with hypertrophic cardiomyopathy

Hypertrophic cardiomyopathy (HCM) is characterized by unexplained left ventricular hypertrophy (LVH) and is one of the major causes of sudden cardiac death (SCD). An exon-targeted gene sequencing strategy was used to investigate the association of functional variants in sarcomeric genes (MYBPC3, MYH7 and TNNT2) with severe LVH and other SCD-related risk factors in Brazilian HCM patients. Clinical data of 55 HCM patients attending a Cardiology Hospital (Sao Paulo city, Brazil) were recorded. Severe LVH, aborted SCD, family history of SCD, syncope, non-sustained ventricular tachycardia and abnormal blood pressure in response to exercise were evaluated as SCD risk factors. Blood samples were obtained for genomic DNA extraction and the exons and untranslated regions of the MYH7, MYBPC3 and TNNT2 were sequenced using Nextera® and MiSEq® reagents. Variants were identified and annotated using in silico tools, and further classified as pathogenic or benign according to the American College of Medical Genetics and Genomics guidelines. Variants with functional effects were identified in MYBPC3 (n = 9), MYH7 (n = 6) and TNNT2 (n = 4). The benign variants MYBPC3 p.Val158Met and TNNT2 p.Lys263Arg were associated with severe LVH (p < 0.05), and the MYH7 p.Val320Met (pathogenic) was associated with family history of SCD (p = 0.037). Increased risk for severe LVH was found in carriers of MYBPC3 Met158 (c.472 A allele, OR = 13.5, 95% CI = 1.80-101.12, p = 0.011) or combined variants (MYBPC3, MYH7 and TNNT2: OR = 12.39, 95% CI = 2.14-60.39, p = 0.004). Carriers of TNNT2 p.Lys263Arg and combined variants had higher values of septum thickness than non-carriers (p < 0.05). Molecular modeling analysis showed that MYBPC3 158Met reduces the interaction of cardiac myosin-binding protein C (cMyBP-C) RASK domain (amino acids Arg215-Ala216-Ser217-Lys218) with tropomyosin. In conclusion, the variants MYBPC3 p.Val158Met, TNNT2 p.Lys263Arg and MYH7 p.Val320Met individually or combined contribute to the risk of sudden cardiac death and other outcomes of hypertrophic cardiomyopathy.

Syncope in the Emergency Department: A Guide for Clinicians

Syncope is a common presenting symptom to emergency departments, but its evaluation and initial management can be challenging for ED practitioners and particularly urgent in the presence of high-risk features that increase the likelihood of cardiac etiology. Even after thorough clinical evaluation, syncope may remain unexplained. In such instances, practitioners' clinical judgment and risk assessments are critical to guide further management. In this article, evidence-informed strategies are outlined to approach the diagnosis of syncope and provide an overview of syncope clinical decision rules and shared decision-making. By incorporating risk stratification and shared decision-making into syncope care, practitioners can more confidently engage patients and families in disposition decisions to organize appropriate outpatient and follow-up care, observation, or admission.

Cardiogenic vertigo: characteristics and proposed diagnostic criteria

Early identification of cardiogenic vertigo (CV) is necessary to prevent serious complications of cardiovascular diseases. However, the literature is limited to case reports without detailed clinical features or diagnostic criteria. The aim of this study was to define characteristics of CV and propose diagnostic criteria. This study included patients with CV diagnosed at Pusan National University and Keimyung University Hospitals. Demographic, clinical, laboratory, and treatment data were analyzed. Of 72 patients with clinically suspicious CV, 27 were finally included. The age ranged from 63 to 88 years (75.1 ± 7.2 years). Recurrent vertigo occurred without syncopal attacks in 52% [95% CI, 32-71], while it preceded (37% [19-58]) or followed (11% [2-29]) syncope. The patients with recurrent isolated vertigo had suffered from symptoms from 15 days to 5 years until final diagnosis (median 122 days). The vertigo lasted only for a few seconds (93% [76-99]) or a few minutes (7% [1-24]). Fourteen patients presented with spinning vertigo, and one of them showed spontaneous downbeat nystagmus during the attack. Accompanying symptoms including chest discomfort, palpitation, headache, arm twitching, and lightheadedness were found in 70% [50-86]. Between patients with and without syncope, there was no difference in clinical parameters and results of cardiac function tests. The most common cardiac abnormality during the attacks of vertigo was bradyarrhythmia (89% [71-98]). Cardiovascular diseases can develop recurrent isolated vertigo without or preceding syncope. Onset age, duration of vertigo, accompanying symptoms, and underlying cardiac diseases can aid in differentiation from other vestibular disorders. Early identification of CV would reduce morbidity and mortality associated with cardiac syncope.

Contemporary management of patients with syncope in clinical practice: an EHRA physician-based survey

Syncope is a heterogeneous syndrome encompassing a large spectrum of mechanisms and outcomes. The European Society of Cardiology published an update of the Syncope Guidelines in 2018. The aim of the present survey was to capture contemporary management of syncope and guideline implementation among European physicians. A 23-item questionnaire was presented to 2588 European Heart Rhythm Association (EHRA) members from 32 European countries. The response rate was 48%, but only complete responses (n = 161) were included in this study. The questionnaire contained specific items regarding syncope facilities, diagnostic definitions, diagnostic tools, follow-up, and therapy. The survey revealed that many respondents did not have syncope units (88%) or dedicated management algorithms (44%) at their institutions, and 45% of the respondents reported syncope-related hospitalization rates &gt;25%, whereas most (95%) employed close monitoring and hospitalization in syncope patients with structural heart disease. Carotid sinus massage, autonomic testing, and tilt-table testing were inconsistently used. Indications were heterogeneous for implanted loop recorders (79% considered them for recurrent syncope in high-risk patients) or electrophysiological studies (67% considered them in bifascicular block and inconclusive non-invasive testing). Non-pharmacological therapy was consistently considered by 68% of respondents; however, there was important variation regarding the choice of drug and device therapy. While revealing an increased awareness of syncope and good practice, our study identified important unmet needs regarding the optimal management of syncope and variable syncope guideline implementation.

Circumstances and causes of death of hikers at different altitudes: A retrospective analysis of hiking fatalities from 2003-2018

INTRODUCTION

The number of hikers and the popularity of hiking in the Alpine region is great. Inevitably linked to this, natural deaths as well as fatal and non-fatal accidents occur. Nevertheless, there is little data available on hiking accidents in particular. This study examines the circumstances of accidents and the causes of death of hikers who have suffered fatal accidents.

METHODS

Retrospectively, the police files and forensic medical reports of hiking fatalities in the Canton of Berne (Switzerland) from 2003 to 2018 were analyzed. In this process 25 predefined parameters were collected (e.g. manner of death, causes of death, height of fall). Subsequently, all fatal hiking accidents were evaluated and compared by altitude (<1800 m vs. >1800 m).

RESULTS

77 fatal hiking accidents were recorded in the given period, all of which were caused by a fall. Over 1800 m significantly more traumatic brain injuries occurred than under 1800 m (85 vs. 62.2 %, p = 0.022). Besides, significantly more accidents occurred during descent in the group above 1800 m than below 1800 m (60.9 vs. 84.8 %, p = 0.041). A large share of accidents occurred off official hiking trails (45.9 vs. 32.5 %). Significantly more equipment shortages were found in the group below 1800 m (32.4 vs. 12.5 %, p = 0.035). The accident victims with equipment shortages were on average 10.35 years younger.

CONCLUSION

Causes and circumstances of death of hikers differ in some points significantly at different altitudes. Prevention in the form of education about the dangers of hiking off the official hiking trails and equipment shortages could prevent deaths in the future. The education should primarily be aimed at foreign, young and inexperienced hikers.

Screening Pediatric Patients in New-Onset Syncope (SPINS) Study

Objectives. The primary objective is to determine the frequency of history findings associated with cardiac syncope. Second, to determine the frequency of abnormal electrocardiograms (EKG) in patients presenting with typical vasovagal syncope. Methods. Retrospective chart review from January 2006 to April 2017 of children aged 5 to 18 years presenting to the emergency department with a chief complaint of syncope. Target population was all patients with first episode of syncope and a documented EKG. Excluded patients were those with head trauma, drug intoxication, current pregnancy, seizure, and any endocrine problem. Patients with cardiac causes of syncope were identified by an abnormal EKG or echocardiogram. Specific history findings (past cardiac history, chest pain, palpitations, syncope with exercise, absence of prodrome with syncope) were compared with those with and without cardiac etiology of syncope. The possibility of missing a patient with cardiac cause of syncope based on specific history findings was identified. Results. Of the total 4115 visits of patients with chief complaints of syncope, 2293 patients (55.7%) met the inclusion criteria. Nine patients (0.39%) were identified with cardiac etiology of syncope. The remaining were determined to be of vasovagal origin. All patients with cardiac etiology of syncope were found to have one positive specific history findings. A total of 1972 patients were identified with absence of specific history findings; no patient had a cardiac etiology of syncope. Conclusions. This study identifies screening questions to identify cardiac syncope. Implementing these standard questions could potentially decrease resource utilization and time for evaluation as well as guide follow-up.

Predictors of the development of non-cardiogenic syncopal conditions at a young age

Aim. Syncopal condition in young people are a relatively frequent and poorly understood medical problem. Non-cardiogenic syncope is not sufficiently studied because often they are not raise fears among doctors or patients, and at the same time their causes are associated with many complex medical and diagnostic aspects. The aim of the presented work is to identify the most significant risk factors in the development of non-cardiogenic syncopal conditions, identify triggers and assess the relationship between these factors, the lifestyle and development of syncope.

Material and methods. The article presents the results of a descriptive research, including 1031 young people with a history of syncope episodes. The study took into account the presence of chronic diseases which could become a syncope trigger. External triggers (prolonged upright staying, stuffy room, and so on) were also determined.

Results. In a multifactor survey of students living in Russia and abroad, the more frequent occurrence of non-cardiogenic syncopal episodes in young girls compared with young men was found. The effect of longterm upright and oxygen corporal were most likely risk factors for syncope.

Conclusion. A significant correlation was found between the onset of reflex syncope and the presence of anemia and autonomic dysfunction syndrome. We proved the absence of a correlation between the level of daily load and the frequency of syncope conditions.

Ethnic differences in lifetime cumulative incidence of syncope: the Malaysian elders longitudinal research (MELoR) study

PURPOSE

To determine the lifetime cumulative incidence of syncope, potential ethnic differences and factors associated with syncope using the Malaysian elders longitudinal research (MELoR) study first wave dataset.

METHODS

The MELoR study recruited community-dwelling adults aged 55 years and over, selected through stratified random sampling from three parliamentary constituencies. The baseline data collected during the first wave was obtained through face-to-face interviews in participants' homes using computer-assisted questionnaires. During their baseline assessments, participants were asked whether they had ever experienced a blackout in their lifetime and if they had experienced a blackout in the preceding 12 months.

RESULTS

Information on blackouts and ethnicity were available for 1530 participants. The weight-adjusted lifetime cumulative incidence of syncope for the overall population aged 55 years and above was 27.7%. The estimated lifetime cumulative incidence according to ethnic groups was 34.6% for Malays, 27.8% for Indians and 23.7% for Chinese. The estimated 12-month incidence of syncope was 6.1% overall, equating to 11.7% for Malays, 8.7 % for Indians and 2.3% for Chinese. Both Malay [odds ratio (OR) 1.46; 95% confidence interval (CI) 1.10-1.95 and OR 3.62, 95% CI 1.96-6.68] and Indian (OR 1.34; 95% CI 1.01-1.80 and OR 3.31, 1.78-6.15) ethnicities were independently associated with lifetime and 12-month cumulative incidence of syncope, respectively, together with falls, dizziness and myocardial infarction.

CONCLUSION

Ethnic differences exist for lifetime cumulative incidence of syncope in community-dwelling individuals aged 55 years and over in an urban area in Southeast Asia. Future studies should now seek to determine potential genetic, cultural and lifestyle differences which may predispose to syncope.

Early Proteome Shift and Serum Bioactivity Precede Diesel Exhaust-induced Impairment of Cardiovascular Recovery in Spontaneously Hypertensive Rats

Single circulating factors are often investigated to explain air pollution-induced cardiovascular dysfunction, yet broader examinations of the identity and bioactivity of the entire circulating milieu remain understudied. The purpose of this study was to determine if exposure-induced cardiovascular dysfunction can be coupled with alterations in both serum bioactivity and the circulating proteome. Two cohorts of Spontaneously Hypertensive Rats (SHRs) were exposed to 150 or 500 μg/m³ diesel exhaust (DE) or filtered air (FA). In Cohort 1, we collected serum 1 hour after exposure for proteomics analysis and bioactivity measurements in rat aortic endothelial cells (RAECs). In Cohort 2, we assessed left ventricular pressure (LVP) during stimulation and recovery from the sympathomimetic dobutamine HCl, one day after exposure. Serum from DE-exposed rats had significant changes in 66 serum proteins and caused decreased NOS activity and increased VCAM-1 expression in RAECs. While rats exposed to DE demonstrated increased heart rate at the start of LVP assessments, heart rate, systolic pressure, and double product fell below baseline in DE-exposed rats compared to FA during recovery from dobutamine, indicating dysregulation of post-exertional cardiovascular function. Taken together, a complex and bioactive circulating milieu may underlie air pollution-induced cardiovascular dysfunction.

Sudden Unexpected Death and the Mammalian Dive Response: Catastrophic Failure of a Complex Tightly Coupled System

In tightly coupled complex systems, when two or more factors or events interact in unanticipated ways, catastrophic failures of high-risk technical systems happen rarely, but quickly. Safety features are commonly built into complex systems to avoid disasters but are often part of the problem. The human body may be considered as a complex tightly coupled system at risk of rare catastrophic failure (sudden unexpected death, SUD) when certain factors or events interact. The mammalian dive response (MDR) is a built-in safety feature of the body that normally conserves oxygen during acute hypoxia. Activation of the MDR is the final pathway to sudden cardiac (SCD) in some cases of sudden infant death syndrome (SIDS), sudden unexpected death in epilepsy (SUDEP), and sudden cardiac death in water (SCDIW, fatal drowning). There is no single cause in any of these death scenarios, but an array of, unanticipated, often unknown, factors or events that activate or interact with the mammalian dive reflex. In any particular case, the relevant risk factors or events might include a combination of genetic, developmental, metabolic, disease, environmental, or operational influences. Determination of a single cause in any of these death scenarios is unlikely. The common thread among these seemingly different death scenarios is activation of the mammalian dive response. The human body is a complex tightly coupled system at risk of rare catastrophic failure when that "safety feature" is activated.