287: The prognosis of syncope associated with a preexcitation syndrome is directly related to the age of the patient

Abstract

Syncope in Wolff-Parkinson-White syndrome (WPW) may reveal an arrhythmic event, but also can be without relationships with WPW. Vagal-related syncope represents the most frequent cause of syncope in population. Electrophysiologic study (EPS) is recommended to evaluate the cause of syncope. The purpose of the study was to evaluate the influence of the age of the patient on the causes of syncope. 97 patients, 51 males, 46 females, mean age 35±17, with WPW were admitted for unexplained dizziness and/or syncope; they had no other heart disease and no documented arrhythmias. EPS consisted of atrial pacing and programmed atrial stimulation using 1 and 2 extrastimuli in control state and after isoproterenol. 29 patients were aged from 9 to 19 years (mean 15±1.4)(children and teenagers/group I). 44 were aged from 20 to 49 years (mean 34±8) (adults/group II). 24 were aged from 50 to 70 years (mean 60±8) (elderly/group III). A potentially malignant form (rapid conduction in accessory pathway (AP) >240 bpm in control state or >300 bpm after isoproterenol and atrial fibrillation or antidromic tachycardia induction) was noted in 10 group I patients (34%) more frequently than in group II patients (5/44) (11%) (p <0.017) and III (0/24) (0%)(p<0.001). Differences between group II and III were not significant (0.08). Orthodromic reentrant tachycardia was induced in 10 group I patients (34%), 20 group II patients (45%) (NS) and 15 group III patients (62.5%)(p<0.04) compared to group I. No tachycardia was induced in 9 group I patients (31%), 19 group II patients (43%)(NS) and 9 group III patients (37.5%)(NS). Syncope in WPW syndrome frequently is directly related to the prexcitation. The cause can be a reentrant tachycardia complicated by a vagal reaction or a rapid atrial fibrillation or tachycardia. The malignant forms as a cause of syncope were frequently noted in children and teenagers, rarely in adults and never in elderly. The management of syncope in children and teenagers with a preexcitation syndrome requires urgently an electrophysiologic study.