[Syncope in patients with normal EKG and without cardiac disease: value of ambulatory esophageal electrophysiology in determining etiology].

The aim of this study was to determine whether ambulatory oesophageal electrophysiological recordings are valuable in identifying the cause of syncope in patients with a normal ECG and without cardiac disease. One hundred and forty-five patients aged 16 to 88 years of age, without cardiac disease, and with a normal ECG without a documented arrhythmia, were examined for unexplained syncope: 55 patients complained of palpitations at the time of syncope. The electrophysiological study was carried out in the clinic with oesophageal recordings using a classical protocol: Wenckebach point and sinus node recovery time were determined; programmed atrial stimulation was used with delivery of 1 and 2 extra-stimuli on the basal rhythm and with 20/30 micrograms infusion of isoprenaline; blood pressure was monitored. The study was negative in 41 patients (28%). Sinus node dysfunction was observed in 9 patients (6%). A vaso-vagal reaction reproducing the symptoms was induced by isoprenaline in 21 patients (14.5%); a conduction defect was revealed in 2 cases (1%). Atrial fibrillation or tachycardia > 1 minute was induced in 22 patients (15%). Paroxysmal junctional tachycardia was induced in 50 patients (35%). Patients with a negative study were younger than those with sinus node dysfunction or atrial fibrillation (44 +/- 21, 71 +/- 9 and 63 +/- 14 years respectively). Treatment was guided by these results: cardiac pacing, antiarrhythmic therapy or radiofrequency ablation of the reentrant pathway were indicated and suppressed syncope in all but two patients. The authors conclude that electrophysiological studies in the out-patient clinic with oesophageal recordings is a safe, rapid and economic method of detecting arrhythmias (sinus node dysfunction or supraventricular tachycardia) in 60% of patients with syncope, especially if they have symptoms of palpitations.