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. 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.

From a large case-control study of 3,877 patients with syncope, 381 patients (9.8%) reported an episode of syncope while driving. A peak of syncope while driving was observed among elderly patients. This has potential public health implications because this peak corresponds to an age group with a higher frequency of accidents per driver-year in the general public. The most common cause of syncope while driving was neurally mediated syncope (37.3%). The next most common identifiable causes were cardiac arrhythmias, including bradyarrhythmias, ventricular tachyarrhythmias, and supraventricular tachyarrhythmias (11.8%). Long-term survival among patients who had syncope while driving (“driving group”) was comparable to that of an age- and sex-matched cohort from the Minnesota population (P=.15). Among the driving group, syncope recurred in 72 patients, 35 of whom (48.6%) had recurrence more than 6 months after the initial evaluation. Syncope while driving again recurred in 10 patients in the driving group, 7 episodes of which (70%) occurred more than 12 months after the initial evaluation. The actuarial recurrence of syncope while driving was 0.7% at 6 months and 1.1% at 12 months during follow-up. The causes of syncope, the late recurrences of syncope (during ≥6 months of follow-up), and the overall low incidence of recurrent syncope while driving again provide useful information to supplement current recommendations on driving for these patients. (Table 1).

Table 1: Causes and Recurrence of Syncopea

 

Groupb

 

Recurrence of Syncope

 

Driving

Nondriving

P Value

Driving

Nondriving

Cause of Syncope

(n=381)

(n=3,496)

(n=72)

(n=713)

Neurally mediated

142 (37.3)

1,247 (35.7)

.54

28 (38.9)

243 (34.1)

Bradyarrhythmia

25 (6.6)

221 (6.3)

.86

9 (12.5)

50 (7.0)

Supraventricular tachyarrhythmia

8 (2.1)

71 (2.0)

.93

3 (4.2)

15 (2.1)

Ventricular tachyarrhythmia

20 (5.2)

130 (3.7)

.14

3 (4.2)

21 (2.9)

Structural cardiopulmonary disease

1 (0.3)

9 (0.3)

.99

0 (0)

3 (0.4)

Cerebrovascular disease

14 (3.7)

100 (2.9)

.37

6 (8.3)

21 (2.9)

Carotid sinus hypersensitivity

12 (3.1)

100 (2.9)

.75

1 (1.4)

30 (4.2)

Orthostatic intolerance

18 (4.7)

223 (6.4)

.20

7 (9.7)

53 (7.4)

Others

87 (22.8)

1,044 (29.9)

.004

11 (15.3)

227 (31.8)

Unknown

90 (23.6)

622 (17.8)

.005

15 (20.8)

111 (15.6)

 

Source

1. Guzman JC, Morillo CA. Syncope and Driving. Cardiol Clin. 2015 Aug;33(3):465-71. doi: 10.1016/j.ccl.2015.04.014. PMID: 26115832. 2. Sorajja D, Nesbitt GC, Hodge DO, Low PA, Hammill SC, Gersh BJ, Shen WK. Syncope while driving: clinical characteri