The number of patients who receive implantable cardioverter defibrillators (ICDs) for both primary and secondary prevention of sudden cardiac death has increased dramatically in recent years. With such widespread use, questions will naturally arise regarding potential lifestyle restrictions after implantation. Indeed, substantial restrictions to a patient’s activities could compromise patients’ willingness to consider implantation of an ICD, despite their proven value as a lifesaving therapy.

       In 1996, the American Heart Association and the North American Society of Pacing and Electrophysiology (NASPE, now the Heart Rhythm Society) published a scientific statement on “Personal and Public Safety Issues Related to Arrhythmias That May Affect Consciousness: Implications for Regulation and Physician Recommendations.”¹ In that document, recommendations were made that focused primarily on patients who had survived a potentially life-threatening ventricular tachyarrhythmia. For patients who had had an episode of ventricular fibrillation (VF) or sustained ventricular tachycardia (VT) and who subsequently underwent implantation of an ICD, the recommendation was made to restrict driving for a period of six months after implantation. Thereafter, patients could resume driving if no further episodes of VT or VF occurred.
       The 1996 recommendations were published just around the time the first results from the primary prevention trials were made public. The Multicenter Automatic Defibrillator Implantation Trial (MADIT) showed a survival benefit from ICD therapy in patients with ischemic cardiomyopathy, left ventricular ejection fraction (EF) less than or equal to 35%, and inducible, non-suppressible ventricular tachycardia.² Since then, multiple other clinical trials have shown similar results, with different patient populations and different methods of risk stratification.^3–7 Most importantly, electrophysiologic studies have not been shown to be critical in risk stratification, with studies such as SCD-HeFT showing that improved survival with ICD therapy can be achieved by implanting devices in patients solely on the basis of symptomatic systolic heart failure with an EF less than or equal to 35%, without further risk stratification.⁶ With such simplification of the patient selection process, many more ICDs are now being implanted for primary prevention of sudden cardiac death, and indeed, they constitute the majority of devices currently being implanted.
       The 1996 recommendations are still valid for patients who receive ICDs for secondary prevention. However, these recommendations are not appropriate for patients who receive ICDs for primary prevention, since by definition no spontaneous ventricular arrhythmia would have occurred at the time of implantation. To restrict the driving privileges of such patients for a prolonged period of time is inappropriate and would lead to limited acceptability of prophylactic ICD therapy. The issue of driving for such patients was discussed briefly in the original document, with the comment that driving not be restricted beyond the initial phase of healing. However, because questions have arisen in this area, there was a need to update and clarify the recommendations. Thus, an addendum to the 1996 Scientific Statement was developed and recently published.⁸
       The major recommendation in the new addendum is that patients who receive ICDs for primary prevention should be restricted from driving for one week after implantation to allow for recovery from the surgical procedure and a short period of observation in case any immediate complications, such as lead instability or inappropriate shocks, were to occur. Thereafter, there is no need to restrict patients who are asymptomatic from an arrhythmia standpoint from driving a private automobile. However, patients should be instructed that impairment of consciousness is possible in the future if an arrhythmia occurs.
       For patients who have received an ICD for primary prevention but who have had an appropriate shock for VT or VF, particularly if they have symptoms of cerebral hypoperfusion, the previously published guidelines for ICDs implanted for secondary prevention apply. Such patients should not drive for six months after the shock. If, within that six-month monitoring period, another appropriate shock occurs, the clock is reset for another six months. Because of the fact that antitachycardia pacing can accelerate VT, a sustained ventricular arrhythmia that is terminated solely with pacing therapy should also lead to a restriction in driving for six months.
       The recommendations from the recent addendum were developed with consideration of the rates of appropriate shocks for patients in the primary prevention trials. For example, the rate of appropriate shocks in SCD-HeFT was 5.1% per year. In a substudy of the Antiarrhythmics Versus Implantable Defibrillators (AVID) trial, a secondary prevention trial in which the event rate would be expected to be higher than for primary prevention patients, 8% of 559 patients who were surveyed had a shock while driving.⁹ Of the total group, 2% reported loss of consciousness while driving and 11% reported dizziness or palpitations that required them to stop the vehicle. From a previous survey of ICD patients, it was estimated that the average ICD patient drives 8–20 miles/day for personal reasons.¹⁰ With total ICD discharge rates from the primary prevention trials averaging 7.5%/year, the likelihood of an ICD discharge while driving would be about 0.15%/year.
       It should be emphasized that these guidelines do not apply to the licensing of commercial drivers. They are governed by federal law, which states that the presence of an ICD for any reason, whether primary or secondary prevention, excludes a patient from commercial driving.
       The ability to drive is an important quality of life issue, particularly in many parts of the country where public transportation is sparse or non-existent. Surprisingly, there have been patients in the past who have been told that implantation of an ICD would proscribe driving for prolonged periods of time, sometimes permanently, even when there had been no history of a spontaneous ventricular tachyarrhythmia. The development of a sensible set of guidelines for primary prevention ICDs that only limit a patient’s driving to the immediate postoperative period should have a positive impact on patients’ willingness to accept this potentially lifesaving therapy.