Physicians often must decide whether patients who experience vasovagal syncope, or fainting, may resume driving. The recent development of recommendations based on symptom severity and class of vehicle driven provides some guidance to physicians, but the actual status of clinical practice is unknown. Lurie and associates conducted a survey to review how physicians who specialize in the treatment of cardiac rhythm disturbances make decisions about allowing their patients to resume driving.

Physicians in nine countries were asked how they evaluate and treat patients with vasovagal syncope. They were also asked to report whether their patients were involved in a motor vehicle accident before or after treatment was initiated. Most physicians (98 percent) routinely used the upright tilt-table test to confirm vasovagal syncope, with a smaller percentage (77 percent) conducting follow-up testing to assess the effectiveness of treatment. Treatment typically consisted of beta-adrenergic drugs or disopyramide. Additional therapies included patient reassurance, fludrocortisone, sertraline, scopolamine patches and ergot alkaloids.

In patients with positive initial results on tilt-table testing and negative results following treatment, physician response to the resumption of driving varied widely, from immediate resumption to one year of abstinence. The average recommended time without driving was approximately 54 days. When results of follow-up testing indicated that treatment was not effective, the variation was even greater. Most respondents (82 percent) believed that patients would ultimately resume driving, but that the actual duration of time needed to be determined on an individual basis. Because syncope that occurs while a patient is sitting was considered more serious than syncope that occurs while standing, most respondents believed patients with the former condition required a longer period without driving. The presence of premonitory symptoms before syncope influenced most respondents to allow driving at an earlier time. Three quarters of the respondents were more cautious about allowing patients to resume driving commercial vehicles, but there was no consensus on the duration of time without driving. Respondents were unable to identify the number of syncope-related accidents before treatment but indicated that only 0.1 to 0.2 percent of patients had been in such an accident after treatment had been initiated.

The authors conclude that when treatment of cardiac arrhythmia is effective, based on head-up tilt-table testing, the average time recommended before resumption of driving was two months, with great variation among respondents. If therapy is not effective, decisions about the resumption of driving were made on an individual basis. The presence of objective criteria, such as “warning” signs and fainting while sitting, influenced physician decision making. In some states, patients who have lost consciousness must be reported, and specific periods of abstinence from driving are mandated.

editor's note: Patients with vasovagal, or neurally mediated, fainting experience a combination of vasodepressor and cardioinhibitory responses. Tilt-table testing is useful in determining susceptibility to this type of fainting, with a sensitivity of 60 to 80 percent and a specificity of 80 to 90 percent. However, therapy cannot be guided by test results, and treatment choices are generally selected on a trial-and-error basis. The value of a subsequent negative tilt-table test during treatment is probably less useful than a period of observation. The American Heart Association has developed recommendations for resumption of driving based on two major assumptions: (1) private driving is thought to be less dangerous than commercial driving; and (2) patients can be categorized as having mild or severe syncope. Patients with mild syncope, defined as near-syncope episodes without true fainting that occur infrequently, only on standing and with a warning sign, can return to personal driving early and to commercial driving after a period of observation. Patients receiving treatment for severe syncope can return to driving after a period of observation. Patients with severe syncope who are not treated should probably not be permitted to drive a commercial vehicle.—r.s.