TRANSOESOPHAGEAL ELECTROPHYSIOLOGICAL STUDY IN PEDIATRIC PATIENTS WITH VENTRICULAR PRE–EXCITATION

Abstract

Abstract Introduction The transoesophageal electrophysiological study (SETE) is a simple, semi–invasive and highly reliable test for risk stratification in patients with ventricular pre–excitation. In paediatric subjects, symptoms may be nonspecific or poorly reported; hence the usefulness of the study in guiding the therapeutic strategy. The guidelines also suggest performing it in all asymptomatic patients with ventricular preexcitation above 8 years of age.Purpose of the study: to evaluate the inducibility of re–entry tachycardia at SETE in paediatric patients with ventricular pre–excitation. Materials and Methods We observed 21 patients aged between a few days of life and 12 years (average age 11 years); 14 of them had constant and 7 intermittent pre–excitations. The latter were subjected to the study as they reported dubious symptoms either due to sports activities or due to a previous diagnosis of neonatal TPS. The study was performed by carrying out the protocols of continuous atrial stimulation at increasing frequencies, programmed atrial stimulation with single, double, and triple extra stimulus and atrial stimulation with burst. Results Of the 21 patients, 8 (38.1%) were inducible. Of the 14 patients with constant ventricular pre–excitation, 5 had tachycardia upon return to the study (35.7%), 4 of which were symptomatic due to previous TPS. Therefore, only one patient with constant and asymptomatic ventricular pre–excitation was inducible. Of the 7 patients with intermittent ventricular preexcitation (documented by Holter or exercise test), 3 developed TPS at SETE (42.8%): all these patients complained of heart palpitations but did not have a documented arrhythmia. On the contrary, all patients with intermittent ventricular preexcitation and asymptomatic were found to be non–inducible. In patients in whom it was possible to calculate the effective antegrade refractory period of the anomalous pathway, shorter refractory period showed greater inducibility. Non–sustained atrial fibrillation was induced in only two patients. Conclusions SETE demonstrates a good correlation between symptoms and inducibility especially in patients with intermittent ventricular pre–excitation. In fact, if the manifest pre–excitation disappears with growth in about a third of patients, the retrograde conduction capacity of the pathway often persists. The study also allows us to identify patients with constant pre–excitation but pathway at low risk.