Motor vehicle accidents in patients with an implantable cardioverter-defibrillator

Driving following defibrillator implantation: development and pilot results from a nationwide questionnaire

BACKGROUND

Implantable cardioverter defibrillator (ICD) implantation is associated with driving restrictions which may have profound effects on the patient's life. However, there is limited patient-reported data on the information given about driving restrictions, the adherence to the restrictions, the incidence of arrhythmic symptoms while driving, and the driving restrictions' effect on ICD patients' daily life and quality of life factors. A specific questionnaire was designed to investigate these objectives, intended for use in a nationwide ICD cohort.

METHODS

The conceptual framework based on literature review and expert opinion was refined in qualitative semi-structured focus group interviews with ten ICD patients. Content validity was pursued through pre-testing, including expert review and 28 cognitive interviews with patients at all ICD implanting centres in Denmark. Finally, the Danish Pacemaker and ICD registry was used to randomly select 50 ICD patients with a first-time implantation between January 1, 2013 and November 30, 2016 for pilot testing, followed by a test-retest on 25 respondents. Test-retest agreement was assessed using kappa statistics or intraclass correlation coefficients.

RESULTS

The pilot test achieved a response rate of 78%, whereof the majority were web-based (69%). Only 49% stated they had been informed about any driving restrictions after ICD implantation, whereas the number was 75% after appropriate ICD shock. Among respondents, 95% had resumed private driving, ranging from 1 to 90 days after ICD implantation. In those informed of a significant (≥ 1 month) driving ban, 55% stated the driving restrictions had impeded with daily life, especially due to limitations in maintaining employment or getting to/from work and 25% admitted they had knowingly been driving during the restricted period. There were six episodes of dizziness or palpitations not necessitating stopping the vehicle. Test-retest demonstrated good agreement of questionnaire items, with 69% of Kappa coefficients above 0.60.

CONCLUSIONS

We have developed a comprehensive questionnaire on ICD patients' perspective on driving. Pre-testing and pilot testing demonstrated good content validity, feasible data collection methods, and a robust response rate. Thus, we believe the final questionnaire, distributed to almost 4000 ICD patients, will capture essential evidence to help inform driving guidelines in this population.

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.

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.

Consensus statement of the European Heart Rhythm Association: updated recommendations for driving by patients with implantable cardioverter defibrillators

Patients with an implantable cardioverter defibrillator (ICD) have an ongoing risk of sudden incapacitation that might cause harm to others while driving a car. Driving restrictions vary across different countries in Europe. The most recent recommendations for driving of ICD patients in Europe were published in 1997 and focused mainly on patients implanted for secondary prevention. In recent years there has been a vast increase in the number of patients with an ICD and in the percentage of patients implanted for primary prevention. The EHRA task force on ICD and driving was formed to reassess the risk of driving for ICD patients based on the literature available. The recommendations are summarized in the following table and are further explained in the document. [table: see text] Driving restrictions are perceived as difficult for patients and their families, and have an immediate consequence for their lifestyle. To increase the adherence to the driving restrictions, adequate discharge of education and follow-up of patients and family are pivotal. The task force members hope this document may serve as an instrument for European and national regulatory authorities to formulate uniform driving regulations.

A pattern analysis of traffic crashes fatal to older drivers

A synthesis of the various crash circumstances in which older drivers die is lacking. This study is based on data from Sweden's national archive of fatal RTCs, and focuses on crashes in which the deceased driver was aged 65+ (2002-2004; n=152). Crash patterns were identified by means of cluster analysis using a sub-set of 12 variables describing both driver and crash event characteristics. Crashes where the driver had died of natural causes prior to crash made up 19.7% of the cases (30 crashes) and were mainly single crashes. Four additional clusters were also identified. Two involved making left turns at intersections, one over-represented among men, occurring typically at weekends, in low-speed areas (30.6%), and the second one, over-represented among women, consisting of crashes in dry road conditions, and on intermediate-speed roads (21.5%). A third cluster included head-on and single-vehicle crashes occurring in dry road conditions but on high-speed roads (29.8%). The last cluster consisted of crashes occurring during the winter and on high-speed roads (18.2%). Older drivers die in traffic in various circumstances, sometimes prior to crashing. Some circumstances cannot be easily alleviated but others could, e.g., through modifications of the road traffic environment and car active safety measures that can help compensate for age-related shortcomings.

Is it safe to allow patients with implantable cardioverter-defibrillators to drive? Learnings from a single center experience

BACKGROUND

Implantable cardioverter-defibrillator (ICD) implant indications have widened in recent years after the publication of the Multicenter Automatic Defibrillator Implantation Trial 2 and the Sudden Cardiac Death in Heart Failure Trial. On the contrary, guidelines on resumption of driving after ICD implant were published almost 10 years ago when the ICD implant rate was much lower and candidates were generally older.

AIM OF THE STUDY

The overall objective of our study was to evaluate whether patients implanted with ICDs have higher risk than the general driving population. The specific aim of the study was to verify the rate of car accidents in patients implanted with an ICD, both for primary and secondary indication, and compare this with the rate of accidents in the general population. The primary end point of the study was the annual car accident rate; the secondary end point was to determine if there were subgroups of patients with a higher risk of car accidents.

METHODS

All patients (612) followed up in our outpatient clinic were sent a questionnaire in which they were asked five questions regarding their driving habits before and after ICD implant and, specifically, whether they had been involved in a car accident after the implant.

RESULTS

Two hundred eighty-six patients (47%) responded to the questionnaire. Seventy-one patients had never driven; two patients were forbidden to drive for professional reasons (one bus and one truck driver). Two hundred thirteen (74.5% of all responding) patients (201 men, mean age 62 +/- 11 years) continued to drive after ICD implant. During the follow-up (1430 +/- 920 days) 11 patients had been involved in car accidents and, importantly 10 out of 11 were innocent bystanders. Thus, in 996 patient-years, 11 events happened, yielding an annual event rate of 1.1% per patient-years (and only 0.1% in which the driver could had been responsible).

CONCLUSION

Car accidents are infrequent in patients implanted with an ICD, and - in any case - not more frequent than in the general population. The old guidelines need to be updated and specific restrictions on car driving in ICD patients need to be revised to reflect the current data.

Syncope following cardioverter defibrillator implantation in patients with spontaneous syncopal monomorphic ventricular tachycardia

AIMS

We sought to determine the incidence, mechanisms, and time to syncope recurrence in patients with spontaneous syncopal monomorphic ventricular tachycardia (SyMVT) treated with an implantable cardiac defibrillator (ICD).

METHODS AND RESULTS

Incidence and causes of syncope following ICD implantation in consecutive patients (n=26) with spontaneous SyMVT were compared with those found in consecutive patients (n=50) with spontaneous non-syncopal monomorphic ventricular tachycardia (NSyMVT). Patients with SyMVT had a higher incidence of syncope (46% patients) than those with NSyMVT (2% patients) at 31+/-21 and 34+/-23 months follow-up, respectively (hazard ratio, 0.19; 95% confidence interval, 0.04-0.42; P=0.0001). Among the former, four patients (15%) had non-arrhythmic syncope and eight patients had arrhythmic syncope (31%), which was associated with either ICD proarrhythmia (seven episodes of VT acceleration or VF degeneration by ATP or low/high-energy shocks in three patients) or spontaneous VT and VF (five episodes in five patients). Median time to the first arrhythmic syncope was 376 days. Arrhythmic syncope presented after a first non-syncopal VT recurrence in six patients (75%).

CONCLUSION

Syncope following ICD implantation is common in patients with SyMVT in contrast to patients with NSyMVT. Late syncope presentation supports reassessment of driving restrictions in this setting.

Psychological Disturbances, Adjustment, and the Development of Phantom Shocks in Patients With an Implantable Cardioverter Defibrillator

The implantable cardioverter defibrillator (ICD), approved for use in 1985, is used to treat potentially lethal ventricular arrhythmias by delivering an electrical impulse to the heart to convert the rhythm back to normal. Since that time, newer studies, such as MADIT II and SCD-HeFT, demonstrated the expanding utility of the ICD, which increases the likelihood of every clinician encountering a patient with an ICD. Patients with an ICD face psychological, physical, and social adjustments. Patients with an ICD, in general, have been shown to have high levels of anxiety, depression, and a sense of helplessness. A subset experiences a phenomenon of phantom shock, which may represent a manifestation of anxiety, depression, or other emotional disturbance. It is important to be aware of this phenomenon, as a phantom shock may either represent or contribute to the patient's maladjustment to the ICD. In lieu of specific screening and treatment options for phantom shock at present, we must use a general approach for recognizing patients experiencing this phenomenon.

Analysis of implantable cardioverter defibrillator therapy in the Antiarrhythmics Versus Implantable Defibrillators (AVID) Trial

INTRODUCTION

The implantable cardioverter defibrillator (ICD) is commonly used to treat patients with documented sustained ventricular tachycardia (VT) or ventricular fibrillation (VF). Arrhythmia recurrence rates in these patients are high, but which patients will receive a therapy and the forms of arrhythmia recurrence (VT or VF) are poorly understood.

METHODS AND RESULTS

The therapy delivered by the ICD was examined in 449 patients randomized to ICD therapy in the Antiarrhythmics Versus Implantable Defibrillators (AVID) Trial. Events triggering ICD shocks or antitachycardia pacing (ATP) were reviewed for arrhythmia diagnosis, clinical symptoms, activity at the onset of the arrhythmia, and appropriateness and results of therapy. Both shock and ATP therapies were frequent by 2 years, with 68% of patients receiving some therapy or having an arrhythmic death. An appropriate shock was delivered in 53% of patients, and ATP was delivered in 68% of patients who had ATP activated. The first arrhythmia treated in follow-up was diagnosed as VT (63%), VF (13%), supraventricular tachycardia (18%), unknown arrhythmia (3%), or due to ICD malfunction or inappropriate sensing (3%). Acceleration of an arrhythmia by the ICD occurred in 8% of patients who received any therapy. No physical activity consistently preceded arrhythmias, nor did any single clinical factor predict the symptoms of the arrhythmia.

CONCLUSION

Delivery of ICD therapy in AVID patients was common, primarily due to VT. Inappropriate ICD therapy occurred frequently. Use of ICD therapy as a surrogate endpoint for death in clinical trials should be avoided.

Automatic implantable cardioverter defibrillator rhythm strip data as used in interpretation of a motor vehicle accident

The automatic implantable cardioverter defibrillator (AICD) is an electronic device that monitors the rhythm of the heart and, upon detecting a life-threatening arrhythmia, shocks the heart in an attempt to restore a normal rhythm. The AICD will electronically store the information of the event. Later, the AICD can be "interrogated" and the information electronically retrieved, with a printout of the rhythm strip obtained. The interrogation is fairly simple and involves a magnetic device placed over the AICD, which in turn is connected to a portable computer, which, with specialized software, can deliver the information in a usable form. Not only can information about the most recent shock be obtained, but also information about previous shocks can be retrieved. This case presentation highlights how such preterminal information retrieved from an AICD helped to interpret the circumstances leading to a death--in this case, a fatal motor vehicle accident. Additionally, driving restrictions that may be placed on individuals with AICDs are discussed.

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.

Baseline factors predicting early resumption of driving after life-threatening arrhythmias in the Antiarrhythmics Versus Implantable Defibrillators (AVID) Trial

BACKGROUND

In the Antiarrhythmics Versus Implantable Defibrillators (AVID) Trial, patients with ventricular fibrillation or hemodynamically unstable ventricular tachycardia were randomly assigned to receive either an implantable cardioverter-defibrillator (ICD) or antiarrhythmic drug therapy. As part of the trial, patients were asked to participate in a prospective driving survey. The purpose of the survey was to determine what baseline factors and patient characteristics specifically predicted resumption of driving earlier than advised by current guidelines.

METHODS

Patients were surveyed anonymously as to their driving habits in the initial period after random assignment and every 6 months thereafter. AVID study coordinators were independently asked to assess their patients' driving status as well. The relation between baseline factors and time to resumption of driving was explored by means of Kaplan-Meier estimates for univariate analyses and the stepwise Cox proportional hazards regression model for multivariate analyses.

RESULTS

There were 802 patients who were eligible for assessment of driving status. The majority of patients (58%) resumed driving an automobile within 6 months of their index arrhythmia regardless of whether they received drug therapy or an ICD. By multivariate analysis, patients who were younger than 65 years of age, male, and college educated were more likely to drive early, as were patients whose index arrhythmia was ventricular tachycardia.

CONCLUSIONS

Younger, college-educated men and those whose index arrhythmia is ventricular tachycardia are most likely to resume driving <6 months after the initiation of therapy for a potentially life-threatening ventricular arrhythmia. Patients with an ICD did not appear to resume driving later than those who were discharged on antiarrhythmic drugs alone.

Implantable Cardioverter Defibrillator: Current Progress and Management

With greater technologic advances during the past decade, use of the implantable cardioverter defibrillator (ICD) has increased to more than 200,000 implants worldwide to date. Indications for ICD implant have expanded to include both patients who have survived sudden cardiac death (secondary prevention of cardiac arrest) and those who are at high risk for experiencing lethal arrhythmias (primary prevention of cardiac ar rest). Thus, it is likely that physicians will encounter defibrillators in their clinical practice and must be familiar with their indications for implant, basic opera tion, and long-term management of devices. Several prospective clinical trials have recently shown the long- term efficacy of ICD therapy at aborting sudden death in the high-risk patient population. Although still evolving, general guidelines and indications for ICD implant have been put forth and are discussed in this review. From the first defibrillation in humans during surgery in 1947 to the sophisticated dual-chamber pacing and memory functions of the modern device, ICD development has led to ever smaller devices with more complex technol ogy. The implant procedure of current ICDs parallels that used to place pacemakers. However, the anesthe sia team plays a vital role in initial ICD implantation by monitoring cardiopulmonary status during defibrilla tion threshold (DFT) testing. Additionally, long-term management of ICDs often requires repeat DFT testing with anesthesia involvement. Finally, possible electro magnetic (environmental) interactions with the ICD of which physicians should be aware are described in this article.

Patients' attitudes toward implanted defibrillator shocks

In addition to its beneficial effect on patient survival, the implanted cardioverter defibrillator (ICD) changes a patient's life physically, socially, and psychologically. For improved patient management, it is important to understand the quality-of-life changes that accompany this mode of treatment. To this end, 119 patients were surveyed retrospectively and interviewed concurrently regarding their emotional, physical, and behavioral responses to ICD shocks and to the device itself. Most (55%) correctly estimated the total number of shocks they had received within a 10% margin. They found the shocks severe, 79% assigning a score between 3 and 5 on a scale of 1-5. Common descriptions of the shock sensation were a blow to the body or a spasm causing the entire body to jump. Most patients tolerated the shocks as lifesaving, but 23% dreaded shocks and 5% even said they would rather be without the ICD and take their chances. After a shock, 50% of patients called their physician and 42% continued their daily routine. Thirty percent went to a hospital emergency room or called a rescue service. Sixty-five percent had no preshock prodromes. Fifty-four percent were interested in the programmable option of a warning signal prior to a shock, while 31% preferred no warning. Of the 74% who were advised not to drive after implantation, 29% drove anyway. Five patients were shocked while driving with no resulting accidents. We conclude that most patients find ICD shocks moderately uncomfortable, but they tolerate them because of the lifesaving protection provided by the device.

Examining the psychosocial impact of implantable cardioverter defibrillators: a literature review

BACKGROUND

The implantable cardioverter defibrillator (ICD) has proven to be superior to medications in treating potentially life-threatening ventricular arrhythmias, resulting in reduced mortality rates. Despite the number of patients receiving this therapy, its psychosocial impact is not well understood.

HYPOTHESIS

The purposes of this paper are (1) to review the available literature documenting the psychosocial impact of the ICD on patients, (2) to hypothesize possible mechanisms for this psychosocial impact, and (3) to suggest clinical risk profiles and indications for psychological consultation.

METHODS

Electronic and library searches (e.g., MEDLINE, PsychLit) were used to gather studies examining the psychosocial impact of the ICD. Only studies investigating psychosocial outcomes (e.g., psychological distress, quality of life, social and role functioning), either prospectively or cross-sectionally, were admitted into the review. No literature reviews or secondary sources were included.

RESULTS AND CONCLUSIONS

Current research suggests that ICD-specific fears and symptoms of anxiety (e.g., excessive worry, physiological arousal) are the most common psychological symptoms experienced by ICD recipients, with approximately 13-38% of recipients experiencing diagnosable levels of anxiety. Depressive symptoms are reported at rates that are generally consistent with other cardiac populations. Although the incidence of psychological disorders appears to be similar to that found in general cardiac populations, specific ICD-related concerns such as fear of shock, fear of device malfunction, fear of death, and fear of embarrassment have been identified. Selected psychological theories such as classical conditioning, learned helplessness, and a cognitive appraisal model help to explain the occurrence of psychological symptoms post implantation. Psychosocial adjustment risk profiles indicate that young ICD recipients and those with high discharge rates may experience the most adjustment difficulties.

Implantable cardioverter-defibrillators

Implantable defibrillators have become the dominant therapeutic modality for patients with life-threatening ventricular arrhythmias. Current defibrillators are small (<60 mL) and implanted with techniques similar to standard pacemakers. They provide high-energy shocks for ventricular fibrillation and rapid ventricular tachycardia, antitachycardia pacing for monomorphic ventricular tachycardia, as well as antibradycardia pacing. Newer devices incorporating an atrial lead allow dual-chamber pacing and better discrimination between ventricular and supraventricular tachyarrhythmias. Randomized controlled trials have shown superior survival with implantable defibrillators than with antiarrhythmic drugs in survivors of life-threatening ventricular tachyarrhythmias and in high-risk patients with coronary artery disease. Complications associated with implantable defibrillator therapy include infection, lead failure, and spurious shocks for supraventricular tachyarrhythmias. Most patients adapt well to living with an implantable defibrillator, although driving often has to be restricted. Limited evidence suggests that implantable defibrillator therapy is cost-effective when compared with other widely accepted treatments. The use of implantable defibrillators is likely to continue to expand in the future. Ongoing clinical trials will define further prophylactic indications of the implantable defibrillator and clarify its cost-effectiveness ratio in different clinical settings.

Dipyridamole stress echocardiography for risk stratification in hypertensive patients with chest pain

BACKGROUND

The noninvasive prognostic assessment of coronary artery disease (CAD) in hypertensive patients represents an unresolved task to date. In this study, we investigated the value of dipyridamole stress echocardiography in risk stratification of hypertensive patients with chest pain and unknown CAD.

METHODS AND RESULTS

Dipyridamole stress echocardiography was performed in 257 hypertensives (110 men; age, 63+/-9 years) complaining of chest pain and without a history of CAD. No major complications occurred. Four tests were interrupted prematurely because of side effects, with 98. 4% feasibility of test. A positive echocardiographic response was found in 72 patients (27 during the low-dose [</=0.56 mg/kg] and 45 during the high-dose [>0.56 mg/kg]). During the follow-up (32+/-18 months), 27 cardiac events occurred: 3 deaths, 8 infarctions, and 16 cases of unstable angina. Moreover, 27 patients underwent coronary revascularization. At multivariate analysis, the positive echocardiographic result (OR, 5.5; 95% CI, 1.4 to 16.6) was the only predictor of hard cardiac events (death, infarction). Considering spontaneous cardiac events (death, infarction, and unstable angina) as end points, the positive echocardiographic result (OR, 4.2; 95% CI, 1.8 to 9.6) and family history of CAD (OR, 4.2; 95% CI, 1.5 to 6. 9) were independently associated with prognosis. The 3-year survival rates for the negative and the positive populations were, respectively, 97% and 87% (P=0.0019) considering hard cardiac events and 96% and 74% (P=0.0000) considering spontaneous cardiac events.

CONCLUSIONS

Dipyridamole stress echocardiography is safe, highly feasible, and effective in risk stratification of hypertensives with chest pain and unknown CAD. At present, it represents an attractive option for prognostic assessment of this clinically defined population.

Mechanisms of syncope in implantable cardioverter-defibrillator recipients who receive device therapies

A significant proportion of implantable cardioverter defibrillator (ICD) recipients ultimately receive device therapies. Determinants and mechanisms of syncopal events in these patients are not established. To address this issue, we reviewed prospectively collected data on 114 ICD recipients who received device therapies. There were 99 men and 15 women with a mean age of 63+/-10 years. Ejection fraction was 29+/-13%. At initial presentation, 74 patients (65%) had syncope during arrhythmia. Of 114 patients, 18 patients (16%) subsequently experienced syncope during device therapies over a period of 35+/-24 months of follow-up. Arrhythmias during syncopal events documented by telemetry, event recorders, RR intervals, or ICD stored electrograms were obtainable in 13 patients, and included sustained monomorphic ventricular tachycardia (VT) in 10 patients, ventricular fibrillation (VF) in 2 patients, and atrial fibrillation in 1 patient. The explanations for arrhythmia-related syncope included ICD proarrhythmia in 8 patients (62%), rapid monomorphic VT in 3 (23%), and VF in 2 patients (15%). Patients with syncope could not be differentiated from those without syncope by demographic, clinical, or electrophysiologic variables. There was no significant difference in mortality between patients with or without syncope (39% vs 25%, p = 0.25). Syncope is not uncommon in ICD recipients who receive device therapies. When it occurs, syncope is often due to ICD proarrhythmia; hence, it is potentially preventable by meticulous device programming.

Psychosocial outcome after ICD implantation: a current perspective

Depression and reduced sexual functioning have been identified as problems following ICD placement. We examined these issues, and multiple other quality-of-life measures, and their relationship to ICD and ICD discharge. Patients were 64 +/- 11 years old, 72% male, and had undergone ICD 20 +/- 14 months previously. Fifty-eight patients responded to a confidential biopsychosocial questionnaire. Positive attitudes toward the procedure increased from 52% before to 76% after implantation. Satisfaction correlated most strongly with less anger (P = 0.002, r = 0.45), less worry about ICD size (P = 0.007, r = 0.38), less sadness (P = 0.01, r = 0.37), and perceived better health (P = 0.01, r = 0.35). Of these ICD patients, 20%-58% reported measures of depression, and sexual frequency was reduced in 45%. Despite successful ICD placement, health concern increased in 62% of the respondents. Thirty-nine percent attended support groups; 96% found them very helpful. Mean number of ICD discharges described by responders was 5 +/- 11. Fifty percent of our sample reported > or = 1 shock; equal numbers had 1, 2-5, 6-10, and more than 10 shocks. Sixty-two percent of men had at least one discharge compared to 13% of women. After controlling for cardiac clinical variables, experiencing > or = 1 ICD shock was strongly associated with anxiety about family (odds ratio = 7.3), reduced new activities (odds ratio = 6.9), increased sadness (odds ratio = 6.2), and health worry (odds ratio = 5.8). Experiencing > or = 5 ICD shocks was strongly associated with increased health concern (odds ratio = 13.6), increased sadness (odds ratio = 12.5), increased fatigue (odds ratio = 6.1), current sadness (odds ratio = 5.8), and increased nervousness (odds ratio = 5.3). ICD implantation powerfully affects quality-of-life. Postimplantation health concern is paradoxically increased despite improvement in actual health. Negative emotions are associated with defibrillator discharge.

Should patients with implantable cardioverter-defibrillators be allowed to drive? Observations in 291 patients from a single center over an 11-year period

Motor-vehicle driving restrictions for patients with implantable cardioverter-defibrillators (ICDs) vary widely throughout the world because safety concerns have never been adequately resolved in this patient population. To address this issue, we examined the driving behavior of 291 ICD patients to correlate the frequency of device therapy during driving, the occurrence of syncopal symptoms, and the incidence of traffic accidents. Fifty of the 291 patients had never driven. Of the remaining 241 patients, 171 (59%) continued driving postimplant and 70 (24%) elected to stop prior to (n = 30) or at the time of ICD implantation (n = 40). Patients were followed for a mean of 38 +/- 26 months (range < 1-124). During this period, no patients died while driving. Of 11 accidents involving 11 driving patients (6%), only 1 was caused by the driver, and none was related to syncopal symptoms or ICD therapy. Although 2 accidents (8%) occurred within 12 months postimplant, the majority (50%) took place after more than 36 months. ICD therapy was delivered in 8 patients (5%) while driving: 13% (1 episode) of the discharges occurred within the first year postimplant, 13% (1 episode) occurred between 1-2 years, and 74% (6 episodes) occurred > 2 years. None of these patients experienced syncope before or during these episodes. A multivariate analysis was unable to identify any variables that might predict increased risk of ICD therapy (with or without sudden death) while driving and consequent motor vehicle accidents. Our data suggest that such events occur only rarely.

The acceptable risk of driving after myocardial infarction: are bus drivers a special case?

BACKGROUND

Bus drivers frequently encounter difficulty in returning to their former employment after recovery from myocardial infarction. The risk that a recurrence of myocardial infarction may cause a personal-injury accident is analyzed.

METHODS

The Cumulative Medical Index and Current Contents was searched systematically from 1980 to date, accepting papers irrespective of language. Relevant earlier material was drawn from the author's published reviews on bus driving and myocardial infarction and vehicle accidents. One hundred twenty-three articles were included in the database, of which 110 were used in the review.

RESULTS

The risk of a personal injury accident or fatality from a sudden cardiovascular incident is calculated as the product of typical driving time per day (Td = 0.167), vehicle characteristics (V) (a low factor of 0.167 for an urban bus because of slow speed and use of reserved curb lanes), the risk of recurrence of a sudden cardiovascular incident (SCI) (.015, somewhat greater in bus drivers than in the general population), and the risk that such an incident will cause a personal-injury accident (Ac) (at 0.005, probably lower than in the general population because of low vehicle speeds and the bus driver's experience in defensive driving).

CONCLUSIONS

The overall risk is 0.00002, 1 in 50,000 driver-years, is lower than accepted for passenger-car operators, and only slightly greater than for the older symptom-free adult. Bus drivers who meet the current standards of the Canadian Cardiovascular Society should be encouraged to return to their former employment.

Syncope in patients with an implantable cardioverter-defibrillator: incidence, prediction and implications for driving restrictions

OBJECTIVES

This retrospective study was undertaken to provide information on occurrence, risk prediction and prevention of syncope in patients with an implantable cardioverter-defibrillator (ICD).

BACKGROUND

ICDs effectively terminate ventricular tachycardia and fibrillation (VT/VF). Incapacitating symptoms, such as syncope, may still occur.

METHODS

We performed a retrospective analysis of data from 421 patients (clinical history, outpatient chart reviews and episode data) with mean (+/-SD) follow-up of 26 +/- 18 months.

RESULTS

Of 421 patients, 229 (54.4%) had recurrent VT/VF, and 62 (14.7%) had syncope. The actuarial survival rate free of VT/VF was 58%, 45% and 37% and that for survival free of syncope was 90%, 85% and 81% at 12, 24 and 36 months after implantation, respectively. Once VT/VF had occurred, 76%, 68% and 62% of patients remained free of syncope during the following 12, 24 and 36 months, and 68%, 64% and 56% remained free of second syncope 12, 24 and 36 months after first syncope, respectively. In cases of syncope, the mean cycle length (CL) of VT was 251 +/- 56 ms. A low baseline left ventricular ejection fraction (LVEF), induction of fast VT (CL <300 ms) during programmed ventricular stimulation and chronic atrial fibrillation (AF) were associated with an increased risk of syncope. If the LVEF was >40%, fast VT had not been induced, and patients had no chronic AF; 96%, 92% and 92% of patients remained free of syncope after 12, 24 and 36 months, respectively. Once patients had a VT recurrence, syncope during the first VT and a high VT rate were the strongest risk predictors of future syncope.

CONCLUSIONS

Identification of patients with an ICD with a low and high risk of syncope seems to be feasible and might help as a guide to driving restrictions in such patients.

Modification of patient driving behavior after implantation of a cardioverter defibrillator

Driving habits among recipients of ICDs have not been well characterized previously, yet such information may have implications for development of national policy. This study was undertaken to characterize driving behavior after defibrillator implantation in our patient population. From 1988-1993, 82 ICDs were implanted at the University of Florida. All patients received defibrillator teaching preoperatively and postoperatively with particular emphasis placed on driving restrictions. A standardized questionnaire was developed to ascertain driving behavior, compliance with restrictions, and occurrence of motor vehicle accidents following implantation. The patients were divided into two groups according to whether or not they had received a shock from their device since implantation. Group I patients did, and Group II patients did not. Fifty-two out of 82 (63%, Group I) patients had at least one shock. The remaining 30 patients had received no shocks. Mean age and gender were no different between the two groups. Mean time since implantation was 6 +/- 1.3 years in Group I, compared to 4 +/- 1.5 years in Group II (P = 0.001). Forty-seven out of 52 (90%) and 26 out of 30 (87%) in Groups I and II, respectively, resumed driving after defibrillator implantation. There was no difference in the amount of time that passed prior to resumption of driving. Group I patients drove more, 20.5 +/- 27 miles/day compared to patients in Group II, 8.3 +/- 9.7 miles/day (P = 0.02). No patient experienced device discharge during driving; likewise, no patient was involved in a motor vehicle accident secondary to their device firing. Sixty-seven out of 82 (82%) patients complied with the instructions they thought they heard; seven patients in Group I and eight patients in Group II deliberately did not follow our advice. The majority of patients do comply with physician instructions, although the instructions they remember are not always the instructions given. If a national policy is created to prohibit driving after ICD implantation, effective enforcement may be difficult.

Driving issues related to arrhythmic syncope

The safety of driving in patients with cardiac arrhythmias is a common concern. Although the risk of driving in these patients cannot be reduced to zero, available data and expert consensus suggest that most patients with arrhythmias can return to driving with a relatively low risk of harm to themselves and others, that is, a risk within the limits deemed acceptable by society. Specific recommendations for allowing patients with various cardiac rhythm abnormalities to drive are reviewed in detail.

Quality of life and driving in recipients of the implantable cardioverter-defibrillator

The efficacy of a treatment is primarily based on objective criteria, such as mortality and morbidity. Besides these criteria, the interest in measuring quality of life (QOL) in relation to health care has increased in recent years. Although the concept of patients' QOL is inherently subjective, and definitions vary, it can be assessed on a basis of 3 major components: physical condition, psychological well-being, and social activities. The basic requirements of QOL assessments are: multidimensional construct, reliability, validity, sensitivity, responsiveness, appropriateness to question or use, and practical utility. The instruments to assess QOL can be disease specific or generic, depending on the context. In 1991 a prospective and systematic evaluation of QOL in implantable cardioverter-defibrillator (ICD) recipients was started at the University of Bonn: psychological profile and patient acceptance were assessed in 57 consecutive patients using a specifically designed questionnaire. The results of this pilot study demonstrated that the acceptance of the ICD was remarkably high. Restrictions on driving a vehicle may have a substantial impact on QOL in patients with ICDs. A specifically designed questionnaire was addressed to 47 European national delegates in order to determine their present practices and criteria utilized when advising driving restrictions to patients after ICD implantation. Of the 39 (83%) respondents, 22 (56%) cardiologists advised all patients to abstain from driving--13 (33%) advising permanent abstinence, while 26 (67%) recommended temporary driving abstinence for periods of 3-18 months (mean 9 +/- 4 months). Despite medical advice not to drive, one third of the patients resume driving; half of the patients resumed driving after 6 months, with the vast majority driving within 12 months after ICD surgery. Two patients experienced ICD discharges while driving, but no motor vehicle accident occurred. Another patient had a motor vehicle collision with a fatal outcome, which was not caused by loss of consciousness or ICD discharge.

CONCLUSIONS

(1) Fatal accidents or ICD discharges while driving are a rare finding in ICD patients. (2) About half of the physicians always advise their patients to cease driving for a period of 9 +/- 4 months. Despite this medical advice, the majority of the patients resume driving within 6 months of ICD implantation. (3) Criteria used in advising driving abstinence are not uniform among physicians.