Can patients with neuromediated syncope safely drive motor vehicles?

Canadian Cardiovascular Society 2023 Guidelines on the Fitness to Drive

Cardiovascular conditions are among the most frequent causes of impairment to drive, because they might induce unpredictable mental state alterations via diverse mechanisms like myocardial ischemia, cardiac arrhythmias, and vascular dysfunction. Accordingly, health professionals are often asked to assess patients' fitness to drive (FTD). The Canadian Cardiovascular Society previously published FTD guidelines in 2003-2004; herein, we present updated FTD guidelines. Because there are no randomized trials on FTD, observational studies were used to estimate the risk of driving impairment in each situation, and recommendations made on the basis of Canadian Cardiovascular Society Risk of Harm formula. More restrictive recommendations were made for commercial drivers, who spend longer average times behind the wheel, use larger vehicles, and might transport a larger number of passengers. We provide guidance for individuals with: (1) active coronary artery disease; (2) various forms of valvular heart disease; (3) heart failure, heart transplant, and left ventricular assist device situations; (4) arrhythmia syndromes; (5) implantable devices; (6) syncope history; and (7) congenital heart disease. We suggest appropriate waiting times after cardiac interventions or acute illnesses before driving resumption. When short-term driving cessation is recommended, recommendations are on the basis of expert consensus rather than the Risk of Harm formula because risk elevation is expected to be transient. These recommendations, although not a substitute for clinical judgement or governmental regulations, provide specialists, primary care providers, and allied health professionals with a comprehensive list of a wide range of cardiac conditions, with guidance provided on the basis of the level of risk of impairment, along with recommendations about ability to drive and the suggested duration of restrictions.

Syncope and the Risk of Subsequent Motor Vehicle Crash: A Population-Based Retrospective Cohort Study

IMPORTANCE

Medical driving restrictions are burdensome, yet syncope recurrence while driving can cause a motor vehicle crash (MVC). Few empirical data inform current driving restrictions after syncope.

OBJECTIVE

To examine MVC risk among patients visiting the emergency department (ED) after first-episode syncope.

DESIGN, SETTING, AND PARTICIPANTS

A population-based, retrospective observational cohort study of MVC risk after first-episode syncope was performed in British Columbia, Canada. Patients visiting any of 6 urban EDs for syncope and collapse were age- and sex-matched to 4 control patients visiting the same ED in the same month for a condition other than syncope. Patients' ED medical records were linked to administrative health records, driving history, and detailed crash reports. Crash-free survival among individuals with syncope was then compared with that among matched control patients. Data analyses were performed from May 2020 to March 2022.

EXPOSURES

Initial ED visit for syncope.

MAIN OUTCOMES AND MEASURES

Involvement as a driver in an MVC in the year following the index ED visit. Crashes were identified using insurance claim data and police crash reports.

RESULTS

The study cohort included 43 589 patients (9223 patients with syncope and 34 366 controls; median [IQR] age, 54 [35-72] years; 22 360 [51.3%] women; 5033 [11.5%] rural residents). At baseline, crude MVC incidence rates among both the syncope and control groups were higher than among the general population (12.2, 13.2, and 8.2 crashes per 100 driver-years, respectively). In the year following index ED visit, 846 first crashes occurred in the syncope group and 3457 first crashes occurred in the control group, indicating no significant difference in subsequent MVC risk (9.2% vs 10.1%; adjusted hazard ratio [aHR], 0.93; 95% CI, 0.87-1.01; P = .07). Subsequent crash risk among patients with syncope was not significantly increased in the first 30 days after index ED visit (aHR, 1.07; 95% CI, 0.84-1.36; P = .56) or among subgroups at higher risk of adverse events after syncope (eg, age >65 years; cardiogenic syncope; Canadian Syncope Risk Score ≥1).

CONCLUSIONS AND RELEVANCE

The findings of this population-based retrospective cohort study suggest that patients visiting the ED with first-episode syncope exhibit a subsequent crash risk no different than the average ED patient. More stringent driving restrictions after syncope may not be warranted.

Driving restrictions for patients with reflex syncope

Reflex syncope is the most common form of syncope that occurs while driving. The 2014 revision of Japanese Road Traffic Laws placed stricter driving restrictions, along with some associated legal penalties, on individuals with recurrent syncope. "Recurrent syncope" is defined as the occurrence of more than two episodes of syncope over a period of 5 years. No restrictions are recommended for private drivers unless they experience syncope without a reliable prodrome while driving or sitting. For commercial drivers, a driving restriction is recommended unless the efficacy of treatment can be confirmed. The "risk of harm" (RH) to other road users appears to be particularly high when commercial driving is involved. The RH formula is calculated using the time of driving, the type of vehicle driven, the risk of sudden cardiac incapacitation, and the probability of a fatal or injury-producing accident. Reducing the driving time or driving a lighter vehicle can reduce the RH. Physicians should talk to their patients about driving and advise their high-risk patients to refrain from driving.

Syncope while driving: clinical characteristics, causes, and prognosis

BACKGROUND

The risk of syncope occurring while driving has obvious implications for personal and public safety. We aimed to define the clinical characteristics, causes, and prognosis of syncope while driving.

METHODS AND RESULTS

In this case-control study of consecutive patients evaluated for syncope from 1996 through 1998 at an academic medical center, we documented causes, clinical characteristics, and recurrence of syncope while driving. Of 3877 patients identified, 381 (9.8%) had syncope while driving (driving group). Compared with the 3496 patients (90.2%) who did not have syncope while driving, the driving group was younger (P=0.01) and had higher percentages of male patients (P<0.001) and patients with a history of any cardiovascular disease (P=0.01) and stroke (P=0.02). Syncope while driving was commonly caused by neurally mediated syncope (37.3%) and cardiac arrhythmias (11.8%). Long-term survival in the driving group was comparable to that of an age- and sex-matched cohort from the Minnesota population (P=0.15). Among the driving group, syncope recurred in 72 patients, 35 of whom (48.6%) had recurrence >6 months after the initial evaluation. Recurrences during driving happened in 10 patients in the driving group, 7 of which (70%) were >12 months after the initial evaluation.

CONCLUSIONS

In our study, neurally mediated syncope was the most common type of syncope while driving. The causes of syncope, the late recurrences of syncope (during > or =6 months of follow-up), and the overall low incidence of recurrent syncope while driving provide useful information to supplement current recommendations on driving for these patients.

Physician reporting of medically impaired drivers

Emergency physicians frequently encounter patients whose medical conditions represent a risk of loss of control while driving, e.g., epilepsy and diabetes. In certain states, physicians are under a legal obligation to report such drivers to the motor vehicular authorities. To determine the uniformity of legislated reporting requirements for physicians caring for patients whose medical conditions represent an automotive hazard, we conducted a survey of Department of Motor Vehicles (DMV) legal departments of all the states in the United States for the academic year 1999-2000 regarding physician reporting of patients with medical conditions that might predispose them to a motor vehicle crash (MVC) and compared the results to a similar study done in 1986. Six (12%) of the states had mandatory reporting laws, 25 (49%) had permissive reporting laws, and 20 (39%) had no laws regarding physician reporting. There was a significant difference between the distribution of laws by year. There was no uniformity on a national level concerning such legislation.

Motor vehicle accident with complete loss of consciousness due to vasovagal syncope

Vasovagal syncope (VVS) is one of the most common causes of complete or partial loss of consciousness, thus it might cause harm to the patients themselves or innocent bystanders while driving a car. In our case report we introduce the case of a 60-year-old man who was admitted to hospital after a serious motor vehicle accident due to loss of consciousness. We demonstrate the process and results of complete cardiologic and neurological assessment. Our case report illustrates the importance of recognition of patients with a high risk for incapacitating symptoms due to VVS, and the use of head-up tilt-table tests to determine the diagnosis and to guide therapy with beta-blocking agents. As transient loss of consciousness during driving may cause potentially fatal accident, it has to be taken into consideration during decision making for issue of driving licenses to patients with VVS.

Syncope: investigation and treatment

Syncope is a common condition that can be both disabling and expensive to treat. Although investigative modalities are sometimes required, a diagnosis can often be made with a good history and physical exam. Recent reports have identified specific historic features that are more suggestive of cardiac syncope as compared with vasovagal syncope and seizures. Advances in ambulatory electrocardiography (in particular the implantable loop recorder) have proven invaluable in both difficult-to-diagnose syncope, and in advancing our knowledge of its mechanisms. When clear dysrhythmias are manifest, appropriate therapies are self-evident. However, recurrent vasovagal syncope continues to be a condition that can be difficult to treat. Fortunately, there are well-conducted trials of both pharmacologic therapies (b-blockers, alpha agonists, and selective serotonin reuptake inhibitors) and nonpharmacologic treatments (orthostatic physical training and dual-chamber pacemakers) that should provide more guidance in the near future.

Resumption of driving after life-threatening ventricular tachyarrhythmia

BACKGROUND

Although the privilege of driving must be respected, it may be necessary to restrict driving when it poses a threat to others. The risks associated with allowing patients with life-threatening ventricular tachyarrhythmias to drive have not been quantified.

METHODS

The Antiarrhythmics versus Implantable Defibrillators (AVID) trial compared antiarrhythmic-drug therapy with the implantation of defibrillators in patients resuscitated from near-fatal ventricular arrhythmias. In the current study, we sent patients who participated in the AVID trial a questionnaire, to be completed anonymously, requesting information about driving habits and experiences.

RESULTS

The questionnaire was returned by 758 of 909 patients (83 percent). Of these, 627 patients drove during the year before their index episode of ventricular tachyarrhythmia. A total of 57 percent of these patients resumed driving within 3 months after randomization in the AVID trial, 78 percent within 6 months, and 88 percent within 12 months. While driving, 2 percent had a syncopal episode, 11 percent had dizziness or palpitations that necessitated stopping the vehicle, 22 percent had dizziness or palpitations that did not necessitate stopping the vehicle, and 8 percent of the 295 patients with an implantable cardioverter-defibrillator received a shock. Fifty patients reported having at least 1 accident, for a total of 55 accidents during 1619 patient-years of follow-up after the resumption of driving (3.4 percent per patient-year). Only 11 percent of these accidents were preceded by symptoms of possible arrhythmia (0.4 percent per patient-year).

CONCLUSIONS

Most patients with ventricular tachyarrhythmias resume driving early. Although it is common for them to have symptoms of possible arrhythmia while driving, accidents are uncommon and occur with a frequency that is lower than the annual accident rate of 7.1 percent in the general driving population of the United States.

Should patients with psychogenic nonepileptic seizures be allowed to drive?

PURPOSE

To investigate the risk of driving accidents in patients with psychogenic nonepileptic seizures.

METHODS

First, a survey was conducted in 82 physician-members of the American Epilepsy Society to determine what they recommend in patients with psychogenic seizures in regard to driving privileges. Second, we studied a population of 20 patients with proven psychogenic nonepileptic seizures diagnosed by prolonged EEG-video monitoring. We obtained the patients' driving records from the Wisconsin Department of Transportation. We used 1991 Wisconsin crash data as the reference year. We compared the expected number of motor vehicle crashes with the observed number of crashes. chi2 with Yates' correction for continuity was used to test for statistical significance.

RESULTS

Of the 82 physicians questioned, 37 (45%) responded. Among respondents, the distribution was as follows: 49% applied the same restrictions as for patients with epilepsy; 32% did not place patients under any restrictions; and 19% decided on a case-by-case basis. The total number of reported crashes in the sample was eight, with no fatal crashes. This was not statistically significant (corrected chi2, 0.53) compared with the expected number of motor vehicle crashes for the sample.

CONCLUSIONS

This small series does not support the use of driving restrictions for patients with psychogenic nonepileptic seizures.

Driving safety among patients with neurocardiogenic (vasovagal) syncope

Neurocardiogenic syncope is one of the most common causes of syncope. However, the important issue of driving related injury due to syncope in this population is not well defined. Risk of injury due to syncope while driving and driving behavior was evaluated in 155 consecutive patients (92 women and 63 men; mean age 49 +/- 19 years) with history of syncope in whom hypotension and syncope or presyncope could be provoked during head-up tilt testing. Patients with syncope and positive head-up tilt table test were treated with pharmacological therapy. All participants were asked to fill out a detailed questionnaire regarding any driving related injuries and their driving behavior before tilt table testing and during follow-up. Prior to head-up tilt testing two patients had syncope while driving, and one of these patients had syncope related injury during driving. The mean duration of syncopal episodes was 50 +/- 14 months (range 12-72 months). Of the 155 patients, 52 (34%) had no warning prior to syncope, while 103 (6%) had warning symptoms such as dizziness prior to their clinical syncope. Following a diagnosis of neurocardiogenic syncope established by head-up tilt testing, six patients stopped driving on their own. During a median follow-up of 22 months recurrent syncope occurred in five (3.2%) patients. No patient had syncope or injury during driving. In conclusion, syncope and injury while driving in patients with neurocardiogenic syncope is rare. The precise mechanism of this is unclear but may be related to posture during driving. Consensus among the medical community will be needed to provide specific guidelines in these patients.

Timing of first recurrence of syncope predicts syncopal frequency after a positive tilt table test result

OBJECTIVES

This study sought to determine whether the time to first recurrence of syncope after a positive isoproteremol-tilt table test result accurately predicts the eventual frequency of syncope.

BACKGROUND

Both patient care and future clinical trials involving patients with neuromediated syncope will require a simple measure that reflects the frequency of syncope. The time from tilt table testing to the first recurrence of syncope might be such a measure.

METHODS

A cohort of 46 patients with syncope, in a university outpatient clinic, who had at least one syncopal spell after a positive isoproterenol-tilt table test result were followed up for up to 6.5 years (mean [+/-SD] 48 +/- 14 months). The time from tilt table testing to the first recurrence of syncope was correlated.

RESULTS

A total of 40 of 46 patients had more than one recurrent spell, with a median of eight recurrent spells. The time to the first syncopal spell predicted the frequency of spells with r = -0.79 (p < 0.001), whereas the time to the second spell predicted the frequency with r = -0.92 (p < 0.001). Patients who fainted within 1 month of tilt testing had a geometric mean frequency of 1.35 spells/month (95% confidence limits 0.49, 3.74) compared with patients who fainted 1 to 24 months after testing (0.12 spells/months; 95% confidence limits 0.07 to 0.18, p < 0.001). Finally, the frequency of syncopal spells bore no relation to the duration of follow-up.

CONCLUSIONS

The time to the first recurrent spell predicts the frequency of syncopal spells after a positive tilt table test result, and the instantaneous risk of syncope is constant.