[Diagnostic transoesophageal atrial stimulation].

BACKGROUND: We wanted to evaluate transoesophageal atrial stimulation as a diagnostic tool in the evaluation of paroxysmal supraventricular tachycardias.

MATERIAL AND METHODS: 185 procedures in 177 patients were evaluated retrospectively. The main reasons for referral to transoesophageal atrial stimulation were documented (52%) or suspected (43%) paroxysmal supraventricular tachycardias. The procedure consisted of incremental atrial stimulation to second degree A-V block, adding up to three extra stimuli, repeating the protocol with isoprenalin 2 and 5 mg/min and completing the procedure with rapid atrial stimulation 300-800/min. Induced tachycardias were classified according to the R-P interval.

RESULTS: The procedure was well tolerated. Supraventricular tachycardias were induced in 72/96 (75%) of patients with documented paroxysmal supraventricular tachycardias and in 41/80 (51%) of patients with suspected paroxysmal supraventricular tachycardias. Out of the 101 patients (55%) who were referred for invasive electrophysiological study, 79 (78%) had an inducible supraventricular tachycardia at transoesophageal stimulation. When stimulation resulted in a tachycardia with measurable R-P interval, the accuracy of our diagnosis was 87%.

INTERPRETATION: Transesophageal atrial stimulation has proved to be a useful diagnostic tool in the management of paroxysmal supraventricular tachycardias at our hospital. Nearly half the patients required no further investigations after transoesophageal atrial stimulation.