Personal and public safety issues related to arrhythmias that may affect consciousness: implications for regulation and physician recommendations. A medical/scientific statement from the American Heart Association and the North American Society of Pacing and Electrophysiology

Vasovagal Syncope at Work: A Narrative Review for an Occupational Management Proposal

Syncope is a complex clinical manifestation that presents considerable diagnostic difficulties and, consequently, numerous critical issues regarding fitness for work, especially for high-risk tasks. To date, it is impossible to quantify the exact impact of syncope on work and public safety since it is highly improbable to identify loss of consciousness as the fundamental cause of work or driving-related accidents, especially fatal injuries. Working at high-risk jobs such as public transport operators, in high elevations, or with exposure to moving parts, construction equipment, fireworks, or explosives demand attention and total awareness. Currently, no validated criteria or indicators are available for occupational risk stratification of a patient with reflex syncope to return to work. By drawing inspiration from the updated literature, this narrative review intends to summarise the leading knowledge required regarding the return to work for subjects affected by syncope. According to the available data, the authors highlighted some key findings, summarised in macro-items, such as defined risk stratification for vasovagal accidents, return to work after a critical event, and a focus on pacemaker (PM) implementation. Lastly, the authors proposed a flowchart for occupational physicians to help them manage the cases of workers affected by syncope and exposed to levels of risk that could represent a danger to the workers' health.

Sudden Cardiac Arrest in the Paediatric Population

Sudden cardiac arrest in the young is a rare event with a range of potential causes including cardiomyopathies, ion channelopathies, and autonomic nervous system dysfunction. Investigations into the cause involve a multidisciplinary team, including cardiologists, geneticists, and psychologists. In addition to a detailed medical history, family history and circumstances surrounding the event are important in determining the cause. Clinical investigations including an electrocardiogram are fundamental in diagnosis and should be interpreted cautiously because some children may have atypical presentations and an evolving phenotype. The potential for misdiagnosis exists that could lead to incorrect long-term management strategies. If an inherited condition is suspected, genetic testing of the patient and cascade screening of family members is recommended with genetic counselling and psychological support. Medical management is left to the treating physician acknowledging that a clear diagnosis cannot be made in approximately half of cases. Secondary prevention implantable defibrillators are widely deployed but can be associated with complications in young patients. A plan for safe return to activity is recommended along with a proper transition of care into adulthood. Broad screening of the general population for arrhythmia syndromes is not recommended; preventative measures include screening paediatric patients for risk factors by their primary care physician. Several milestone events or activities that take place in youth could be used as opportunities to promote safety. Further work into risk stratification of this paediatric population through patient registries and greater awareness of cardiopulmonary resuscitation and automated external defibrillator use in saving lives is warranted.

The impact of age, type 2 diabetes and hypertension on heart rate variability during rest and exercise at increasing levels of heat stress

PURPOSE

In older adults with type 2 diabetes (T2D) and hypertension (HTN), cardiac autonomic modulation is markedly attenuated during exercise-heat stress. However, the extent to which this impairment is evident under increasing levels of heat stress remains unknown.

METHODS

We examined heart rate variability (HRV), a surrogate of cardiac autonomic modulation, during incremental exercise-heat stress exposures in young (20-30 years) and middle-aged-to-older individuals (50-70 years) without and with T2D and HTN. Thirteen young and healthy (Young, n = 13) and 37 older men without (Older, n = 14) and with HTN (n = 13) or T2D (n = 10) performed 180-min treadmill walking at a fixed metabolic rate (~ 200 W/m²; ~ 3.5 METs) in a differing wet-bulb globe temperature (WBGT; 16 °C, 24 °C, 28 °C, and 32 °C). Electrocardiogram (ECG) and core temperature measurements were recorded throughout. Data were analysed using 5-min averaged epochs following 60-min exercise, which represented the last common timepoint across groups and conditions.

RESULTS

Ageing did not significantly reduce HRV during increasing exercise-heat stress (all p > 0.050). However, T2D and HTN modified HRV during exercise-heat stress such that Detrended Fluctuation Analysis (DFA) α₁ (p = 0.012) and the cardiac sympathetic index (p = 0.037) were decreased compared to Older in all except the warmest WBGT condition (32 °C).

CONCLUSION

Our unique observations indicate that, relative to their younger counterparts, HRV in healthy older individuals is not perturbed during exercise heat-stress. However, relative to their age-matched healthy counterparts, HRV is reduced during exercise-heat stress in individuals with age-associated chronic conditions, indicative of cardiac autonomic dysfunction.

Driver Cardiovascular Disease Detection Using Seismocardiogram

This article deals with the treatment and application of cardiac biosignals, an excited accelerometer, and a gyroscope in the prevention of accidents on the road. Previously conducted studies say that the seismocardiogram is a measure of cardiac microvibration signals that allows for detecting rhythms, heart valve opening and closing disorders, and monitoring of patients' breathing. This article refers to the seismocardiogram hypothesis that the measurements of a seismocardiogram could be used to identify drivers' heart problems before they reach a critical condition and safely stop the vehicle by informing the relevant departments in a nonclinical manner. The proposed system works without an electrocardiogram, which helps to detect heart rhythms more easily. The estimation of the heart rate (HR) is calculated through automatically detected aortic valve opening (AO) peaks. The system is composed of two micro-electromechanical systems (MEMSs) to evaluate physiological parameters and eliminate the effects of external interference on the entire system. The few digital filtering methods are discussed and benchmarked to increase seismocardiogram efficiency. As a result, the fourth adaptive filter obtains the estimated HR = 65 beats per min (bmp) in a still noisy signal (SNR = −11.32 dB). In contrast with the low processing benefit (3.39 dB), 27 AO peaks were detected with a 917.56-ms peak interval mean over 1.11 s, and the calculated root mean square error (RMSE) was 0.1942 m/s2 when the adaptive filter order is 50 and the adaptation step is equal to 0.933.

Management of cardiac conduction abnormalities and arrhythmia in aircrew

Cardiovascular diseasesⁱ are the most common cause of loss of flying licence globally, and cardiac arrhythmia is the main disqualifier in a substantial proportion of aircrew. Aircrewⁱⁱ often operate within a demanding physiological environment, that potentially includes exposure to sustained acceleration (usually resulting in a positive gravitational force, from head to feet (+Gz)) in high performance aircraft. Aeromedical assessment is complicated further when trying to discriminate between benign and potentially significant rhythm abnormalities in aircrew, many of whom are young and fit, have a resultant high vagal tone, and among whom underlying cardiac disease has a low prevalence. In cases where a significant underlying aetiology is plausible, extensive investigation is often required and where appropriate should include review by an electrophysiologist. The decision regarding restriction of flying activity will be dependent on several factors including the underlying arrhythmia, associated pathology, risk of incapacitation and/or distraction, the type of aircraft operated, and the specific flight or mission criticality of the role performed by the individual aircrew.

A Review of Driving Restrictions in Patients at Risk of Syncope and Cardiac Arrhythmias Associated with Sudden Incapacity: Differing Global Approaches to Regulation and Risk

The ability to drive is a highly valued freedom in the developed world. Sudden incapacitation while driving can result in injury or death for the driver and passengers or bystanders. Cardiovascular conditions are a primary cause for sudden incapacitation and regulations have long existed to restrict driving for patients with cardiac conditions at high risk of sudden incapacitation. Significant variation occurs between these rules in different countries and legislatures. Quantification of the potential risk of harm associated with various categories of drivers has attempted to make these regulations more objective. The assumptions on which these calculations are based are now old and less likely to reflect the reality of modern driving. Ultimately, a more individual assessment of risk with a combined assessment of the medical condition and the patient's driving behaviour may be appropriate. The development of driverless technologies may also have an impact on decision making in this field.

The importance of return to work: How to achieve optimal reintegration in ACS patients

The vocational reintegration of patients after an acute coronary syndrome is a crucial step towards complete convalescence from the social as well as the individual point of view. Return to work rates are determined by medical parameters such as left ventricular function, residual ischaemia and heart rhythm stability, as well as by occupational requirement profile such as blue or white collar work, night shifts and the ability to commute (which is, in part, determined by physical fitness). Psychosocial factors including depression, self-perceived health situation and pre-existing cognitive impairment determine the reintegration rate to a significant extent. Patients at risk of poor vocational outcomes should be identified in the early period of rehabilitation to avoid a reintegration failure and to prevent socio-professional exclusion with adverse psychological and financial consequences. A comprehensive healthcare pathway of acute coronary syndrome patients is initiated by cardiac rehabilitation, which includes specific algorithms and assessment tools for risk stratification and occupational restitution. As the first in its kind, this review addresses determinants and legal aspects of reintegration of patients experiencing an acute coronary syndrome, and offers practical advice on reintegration strategies particularly for vulnerable patients. It presents different approaches and scientific findings in the European countries and serves as a recommendation for action.

Inappropriate implantable cardioverter defibrillator shocks-incidence, effect, and implications for driver licensing

Purpose

Patients with implantable cardioverter defibrillators (ICDs) have an ongoing risk of sudden incapacitation that may cause traffic accidents. However, there are limited data on the magnitude of this risk after inappropriate ICD therapies. We studied the rate of syncope associated with inappropriate ICD therapies to provide a scientific basis for formulating driving restrictions.

Methods

Inappropriate ICD therapy event data between 1997 and 2014 from 50 Japanese institutions were analyzed retrospectively. The annual risk of harm (RH) to others posed by a driver with an ICD was calculated for private driving habits. We used a commonly employed annual RH to others of 5 in 100,000 (0.005%) as an acceptable risk threshold.

Results

Of the 4089 patients, 772 inappropriate ICD therapies occurred in 417 patients (age 61 ± 15 years, 74% male, and 65% secondary prevention). Patients experiencing inappropriate therapies had a mean number of 1.8 ± 1.5 therapy episodes during a median follow-up period of 3.9 years. No significant differences were found in the age, sex, or number of inappropriate therapies between patients receiving ICDs for primary or secondary prevention. Only three patients (0.7%) experienced syncope associated with inappropriate therapies. The maximum annual RH to others after the first therapy in primary and secondary prevention patients was calculated to be 0.11 in 100,000 and 0.12 in 100,000, respectively.

Conclusions

We found that the annual RH from driving was far below the commonly cited acceptable risk threshold. Our data provide useful information to supplement current recommendations on driving restrictions in ICD patients with private driving habits.

Electronic supplementary material

The online version of this article (doi:10.1007/s10840-017-0272-4) contains supplementary material, which is available to authorized users.

Driving restrictions in patients with implantable cardioverter defibrillators and pacemakers

Implantable cardioverter-defibrillators (ICDs) improve the survival in patients at risk of sudden cardiac death. However, these patients have an ongoing risk of sudden incapacitation that may cause harm to individuals and others when driving. Considerable disagreement exists about whether and when these patients should be allowed to resume driving after ICD therapies. This information is critical for the management decisions to avoid future potentially lethal incidents and unnecessary restrictions for ICD patients. The cardiac implantable device committee of the Japanese Heart Rhythm Society reassessed the risk of driving for ICD patients based on the literature and domestic data. We reviewed the driving restrictions of ICD patients in various regions and here present updated Japanese driving restrictions.

Sports and Driving With an Implantable Cardioverter-Defibrillator

Many patients with implantable cardioverter-defibrillators (ICD) want to participate in sports and many need or wish to operate a personal motor vehicle. Healthcare providers need to advise patients regarding restrictions related to these activities in the context of the clinical indication for the ICD. Ethical considerations need to be considered when advising ICD patients of restrictions to reduce risk of injury to themselves and to others when participating in either sports or driving. Shared decision-making is necessary to have ICD patients understand and comply with recommended restrictions. Guidelines have been developed based on available studies; however, studies assessing the need for ICD patients to restrict these activities are observational and often out of date. More recent studies challenge driving and sports restrictions that are recommended by the guidelines. Recommendations to ICD patients must be individualized yet be compliant with the guidelines, and need to adapt to changes in a patients' condition.

Clinician Effectiveness in Assessing Fitness to Drive of Medically At-Risk Older Adults

OBJECTIVES

To model the relative contributions of driver data and clinical judgments to clinical ratings of driver capability for a state licensing authority and to compare ratings with on-road test results.

DESIGN

Retrospective, logistic regression.

SETTING

Missouri Driver License Bureau.

PARTICIPANTS

Adults aged 60 and older (N = 652; 52% male) evaluated by a physician of their choosing and a portion subsequently road tested (n = 286).

MEASUREMENTS

Clinical data from an evidence-based physician statement (Form 1528). A three-level rating (likely capable, unclear, not capable) was collapsed into two outcomes (0 likely capable; 1 unclear, not capable) as the dependent variable. Independent variables (predictors) were age, sex, driving exposure, recent crash or police action, number of medical conditions, medication side effects, driver insight, and disease functional severity rating for driving.

RESULTS

Three variables in the model (Nagelkerke coefficient of determination = 0.64; P < .001) were significant in the expected direction: disease functional severity for driving (odds ratio (OR = 6.65), insight (OR = 2.35), and age (OR = 1.06). Proportionately more drivers rated likely capable (73%) passed the road test than those rated unclear or not capable (62%).

CONCLUSION

Judgments of disease severity, decrements in driver insight, and older age influenced clinician ratings of driving capability. Correspondence of physician ratings to on-road test outcomes was imperfect, highlighting the complexities in translation of clinical judgments to on-road performance. Both means of assessment have important and additive roles in driver licensing.

Syncope and Driving

The occurrence of syncope while driving has obvious implications for personal and public safety. Neurally mediated syncope is the most common type of syncope in general and, thereby, also while driving. The presence of structural heart disease (reduced ejection fraction, previous myocardial infarction, significant congenital heart disease) potentially leads to high risk and should determine driving restrictions pending clarification of underlying heart disease and etiology of syncope. The clinical approach to syncope evaluation and recommendations for driving should not differ, whether or not the syncopal spell occurred while driving.

ED evaluation and management of implantable cardiac defibrillator electrical shocks

Patients with implantable cardiac defibrillators not infrequently present to the emergency department after experiencing an implantable cardiac defibrillator shock. This review considers the management of such patients in the emergency department, including appropriate, inappropriate, and phantom shocks as well as electrical storm.

Bias in counseling of seizure patients following a transient impairment of consciousness: differential adherence to driver fitness guidelines

PURPOSE

To determine primary care physicians' counseling as well as patients' driving behaviors following seizure and non-seizure events impairing consciousness in the community.

METHODS

Patients attending a rapid-referral first seizure clinic were entered into the study if they were deemed medically-unfit to drive according to national guidelines for driving licensure: had experienced a seizure or an unexplained episode of lost consciousness, and had a valid driver's license at the time of their index event. Risk of physician counseling in the community regarding driving cessation in the interval between initial primary care assessment and neurological consultation was examined as a primary outcome, and patient driving cessation was examined as a secondary outcome.

RESULTS

106 of 192 (55%) patients attending clinic met guideline criteria requiring driver fitness counseling in the primary care community, and 89 patients (46%) were deemed medically-unfit to drive following the initial specialist consultation appointment. Among medically unfit driver cases, 73% were ultimately deemed to have experienced a seizure and 27% had experienced a non-seizure event (e.g. syncope, PNES). Driver fitness counseling was more likely for seizure than non-seizure cases (unadjusted odds ratio: 4.14, p<0.05), as was patient driving cessation (5.10, p<0.05).

CONCLUSION

Physician compliance with clinical practice guidelines appears strongly biased when counseling about driving following an episode of transient impairment in consciousness. The failure of the primary care medical community to apply driver fitness counseling equitably to both seizure and non-seizure drivers may have ramifications upon public safety or conversely disease-related quality-of-life.

[The electrophysiology of Wolff-Parkinson-White in the asymptomatic patient with activity or with high professional risk]

OBJECTIVE

Describe the electrophysiological characteristics in subjects with asymptomatic Wolff-Parkinson-White with sports activities or high professional responsibility.

METHODS

Nineteen subjects, mean age 33 ± 13 years (group A). The electrophysiological characteristics were compared with a matched group with symptomatic WPW (group B).

RESULTS

At baseline the anterograde refractory period and the anterograde conduction 1:1 over the accessory pathway were longer in group A (300 ± 48 ms vs 262 ± 32 ms, p < 0.05 and 355 ± 108 ms vs 307 ± 86 ms, p < 0.05), respectively. None of group A had a anterograde refractory period< 250 ms and 58% showed absence of retrograde conduction over the accessory pathway vs 4% of group B (p < 0.001). Induction of tachycardia was significantly less in group A (5%) than in group B (92%) (p < 0.001). Atrial fibrillation was induced in only one of group A vs 32% of group B (p < 0.001).

CONCLUSION

We confirm the benign electrophysiological characteristics in asymptomatic compared to symptomatic subjects. Poor anterograde conduction along with absence of retrograde conduction explains the low frequency of tachyarrhythmias and would not support the routine investigation of all asymptomatic subjects. But, due to possible consequences, remains the systematic indication for preventive ablation in the subgroup of asymptomatic subjects with sporting activities or high professional responsibility.

Cardiac Resynchronization Therapy With and Without Defibrillator in a Commercial Truck Driver with Ischemic Cardiomyopathy and New York Heart Association Class III Heart Failure

Commercial drivers warrant tighter restrictions to their driving privileges than private drivers. Patients with cardiac disease who are at risk of consciousness-impairing arrhythmias are not allowed to drive commercially. Patients with left ventricular systolic dysfunction and/or heart failure symptoms are permanently disqualified from commercial driving. A biventricular pacemaker without defibrillator can improve symptoms and mortality in selected patients with heart failure. Biventricular pacing may have antiarrhythmic effects that may reduce the added benefit of a defibrillator. Motor vehicle collisions resulting from arrhythmic events are infrequent. The interests of public safety must outweigh individual liberties when driving safety is in question.

Evaluation and management of arrhythmia in the athletic patient

Athletes may present with palpitations, syncope, or arrest resulting in the diagnosis of arrhythmia, or screening may result in diagnosis of conditions with predisposition to arrhythmia. This chapter focuses on 3 common arrhythmic conditions in athletes-atrial fibrillation, premature ventricular contractions (PVCs), and the athlete with an implanted device. (1) Atrial fibrillation: most studies show that atrial fibrillation is more common in competitive athletes, particularly those participating in long-term endurance sports. Postulated mechanisms include morphologic changes such as atrial dilatation, autonomic changes such as increased vagal tone, or inflammatory changes due to sports participation. Treatment options include long-term antiarrhythmic agents, "pill in the pocket" medications, or radiofrequency ablation, a highly successful procedure in athletes. (2) Premature ventricular contractions: data conflict on whether the incidence of PVCs is increased in highly trained individuals. Very frequent PVCs in athletes, however, can be a manifestation of underlying heart disease, and athletes presenting with PVCs should undergo evaluation. In the absence of underlying heart disease, PVCs do not carry a poor prognosis, and US guidelines do not recommend restriction from sports. (3) Implanted devices: the safety of sports for the athlete with an implanted device is unknown, and current guidelines recommend against participation in vigorous competitive sports, based on postulated risks including failure to defibrillate and risk of injury. Many athletes with defibrillators and pacemakers do participate in sports. Ongoing research will better delineate the risks of sports for the athlete with an implanted device.

Driving restrictions after implantable cardioverter defibrillator implantation: an evidence-based approach

Aims

Little evidence is available regarding restrictions from driving following implantable cardioverter defibrillator (ICD) implantation or following first appropriate or inappropriate shock. The purpose of the current analysis was to provide evidence for driving restrictions based on real-world incidences of shocks (appropriate and inappropriate).

Methods and results

A total of 2786 primary and secondary prevention ICD patients were included. The occurrence of shocks was noted during a median follow-up of 996 days (inter-quartile range, 428–1833 days). With the risk of harm (RH) formula, using the incidence of sudden cardiac incapacitation, the annual RH to others posed by a driver with an ICD was calculated. Based on Canadian data, the annual RH to others of 5 in 100 000 (0.005%) was used as a cut-off value. In both primary and secondary prevention ICD patients with private driving habits, no restrictions to drive directly following implantation, or an inappropriate shock are warranted. However, following an appropriate shock, these patients are at an increased risk to cause harm to other road users and therefore should be restricted to drive for a period of 2 and 4 months, respectively. In addition, all ICD patients with professional driving habits have a substantial elevated risk to cause harm to other road users during the complete follow-up after both implantation and shock and should therefore be restricted to drive permanently.

Conclusion

The current analysis provides a clinically applicable tool for guideline committees to establish evidence-based driving restrictions.