[Is the transesophageal approach preferable to endocavitary approach in the evaluation of Wolff-Parkinson-White syndrome?].

Now that the radical treatment of the Wolff-Parkinson-White syndrome is established, it is essential to evaluate the prognosis of this condition accurately. Initiation of atrial fibrillation is one of the factors which influence the prognosis. The aim of this study was to compare the results of electrophysiological studies performed by the endocavitary and transoesophageal approaches in the measurement of the initiation of atrial fibrillation. Twenty-six patients with a patent Wolff-Parkinson-White syndrome were studied by the two methods with a similar protocol: incremental atrial pacing to the Wenckebach point, programmed atrial stimulation using up to two extrastimuli, repeated with an infusion of 20 to 30 ug of isoproterenol. Sixteen patients had reciprocating nodal tachycardia or were asymptomatic (group I) and the other 10 had spontaneous atrial fibrillation (group II). In group I, atrial fibrillation was induced in 9 cases (56%) by the endocavitary and in two cases (12.5%) by the transoesophageal method. In group II, spontaneous atrial fibrillation was reproduced in all cases by the endocavitary and transoesophageal protocols. None of the patients in group I developed atrial fibrillation during follow-up (average 2 years +/- 9 months). The authors observe that all spontaneous atrial fibrillation of the Wolff-Parkinson-White syndrome can be triggered by oesophageal stimulation. The prevalence of atrial fibrillation was overestimated by endocavitary studies in asymptomatic or paucisymptomatic patients. The assessment of atrial vulnerability of a Wolff-Parkinson-White syndrome may therefore be performed by transoesophageal electro-physiological studies.