Comparison of transesophageal and intracardiac electrophysiologic studies in characterization of supraventricular tachycardi in pediatric patients

Objectives. This study sought to determine the accuracy of transesophageal electrophysiologic studies in diagnosing and characterizing various mechanisms of supraventricular tachycardi in pediatric patients. Background. Transesophageal electrophysiologic studies are relatively noninvasive means of characterizing supraventricular tachycardia. Although widely used, to our knowledge no dat exist that directly compare information obtained from transesophageal electrophysiologic studies with that from intracardiac electrophysiologic studies. Methods. We reviewed the records of 57 pediatric patients undergoing both transesophageal and intracardiac electrophysiologic studies at our institution. The results of these studies were compared with respect to mechanism of tachycardia, localization of accessory atrioventricular (AV) connections (if present) and characterization of anterograde accessory connection conduction properties. Results. Tachycardi mechanisms were concordant in 56 of 57 patients: orthodromic reciprocating tachycardi in 43, antidromic reciprocating tachycardi in 1, both orthodromic and antidromic tachycardi in 2, AV node reentrant tachycardi in 5, atrial reentrant tachycardi in 4 and ectopic atrial tachycardi in 2. Of 29 patients with orthodromic reciprocating tachycardi using concealed accessory connection, transesophageal study predicted the accessory connection site through changes induced by transient bundle branch block in 12. By the Bland-Altman method in 14 patients with pre-excitation, the anterograde accessory connection effective refractory period determined by transesophageal study compared favorably with that determined by intracardiac study (mean difference 5.0 ms, limits of agreement −55 and 65 ms). Conclusions. Transesophageal electrophysiologic studies are highly accurate means of diagnosing and characterizing various mechanisms of supraventricular tachycardi in pediatric patients.