Jean Paul Lethor

Rapid and low-cost method to prove the nature of no documented tachycardia in children and teenagers without pre-excitation syndrome

Aims Symptoms in children are often difficult to interpret. The purpose of this study was to report the results of transoesophageal electrophysiological study (EPS) performed in children complaining of sudden onset tachycardia with normal non-invasive studies. Methods and results Eighty-two children and teenagers (mean age 15 +/- 3 years) presented with suspected but no documented paroxysmal supraventricular tachycardia (SVT). ECG was normal. Non-invasive studies were negative; 23 children had syncope with tachycardias. They underwent transoesophageal EPS in our out-patient clinic. The mean duration of transoesophageal EPS was 11 +/- 5 min. Electrophysiological study was negative in 25 children. AV nodal re-entrant tachycardia could be induced in 37 children, 11 of them associated with syncope. Wolff-Parkinson-White syndrome (WPW) was diagnosed in five children in which atrioventricular re-entrant tachycardia was inducible. Atrioventricular re-entrant tachycardia due to a concealed AP was induced in 14 children. Verapamil-sensitive ventricular tachycardia was induced in one patient. Factors associated with tachycardia inducibility were an older age (15.5 +/- 2 vs. 14 +/- 4 years) (P < 0.05) and the absence of syncope (81 vs. 52%) (P < 0.05). During a mean follow-up of 3 +/- 1 year, no patient with negative EPS developed documented tachycardia. In 17 children with inducible SVT, radiofrequency ablation of the re-entrant circuit was subsequently performed. Conclusion Transoesophageal EPS is a fast method for proving the nature of paroxysmal tachycardia in children and teenagers presenting with normal ECG and for demonstrating WPW syndrome not visible on standard ECG. The negative predictive value of transoesophageal EPS for the diagnosis of SVT was 100%.

Age‐Related Prognosis of Syncope Associated with a Preexcitation Syndrome

Syncope in Wolff‐Parkinson‐White syndrome (WPW) is without relationship with WPW or reveals a poorly tolerated arrhythmia. Electrophysiologic study (EPS) is recommended. The purpose of the study was to evaluate the influence of the patients age on the causes and prognosis of syncope.

0164: Evolution of preexcitation syndrome in children

Previous studies reported a spontaneous disappearance of preexcitation syndrome (PS) in patients with a long accessory pathway (AP) effective refractory period (ERP) and in children 12 y with inducible SVT and short AP-ERP. The purpose of the study was to collect the data of untreated children with a PS, studied 2 times at least one year of interval. Methods 2 baseline electrophysiological studies (EPS) were performed within 1 to 25 years of one another (mean 6±years) in 39 children and teenagers, 17 boys, 22 girls, aged initially from 1 to 19 years (12.5±4), with overt PS. First EPS (EPS1) was indicated for syncope (n=4), atrioventricular reentrant tachycardias (AVRT)(n=17) or for asymptomatic PS (n=18). The protocol was similar, performed in control state (CS) and after isoproterenol. Results At EPS2, among patients studied for syncope at EPS1, 1 has still syncope, 2 have AVRT, 1 is asymptomatic. Among patients with AVRT at EPS1, 14 (82%) have still AVRT, 3 are asymptomatic. Among asymptomatic patients, 13 (72%) remain asymptomatic, 2 have AVRT, 3 have syncope. AVRT in children presenting initially with syncope or initially asymptomatic children occurred in 2/4 with inducible AVRT at EPS1. The higher rate conducted by AP was similar in CS and after isoproterenol at EPS2 (178±72bpm, 203±81) and at EPS1 (188±62, 237±83)(p Conclusions Contrary to previous studies, we did not find significant changes of clinical and electrophysiological data in children after a mean follow-up of 6±5 years. Most of children with spontaneous or inducible AVRT’s at the first evaluation have still inducible AVRT’s at the second evaluation. AP-ERP did not increase significantly.

0034: Preexcitation syndrome and atrioventricular nodal reentrant tachycardia: coincidence or not?

Background Reciprocating tachycardia which occurs in patients with a preexcitation syndrome (PS) generally is directly related to the presence of the accessory pathway (AP) and is called atrioventricular re-entrant tachycardia (AVRT). The purpose of the study was to evaluate the incidence of re-entrant tachycardia of other nature among patients with a PS. Methods 785 patients with paroxysmal tachycardia were admitted AP ablation, 294 patients with a concealed AP (group I) and 491 patients with a Wolff-Parkinson-White syndrome (WPW) (group II). Programmed atrial stimulation was performed in the control state and if necessary after isoproterenol to induce the clinical tachycardia and determine its mechanism. Results AVRT was induced in 760 patients (97%), 282 of group I (96%)and 478 of group II (97%) (NS). Atrioventricular nodal re-entrant tachycardia (AVNRT) was induced in 13 group I patients (4.6%) and 12 group II patients(2.5%) (NS; 0.11). In 9 group I patients (3%) and in 4 group II patients (1%) (p Conclusions In patients with concealed or patent accessory pathway and complaining of paroxysmal tachycardia, a careful evaluation of the mechanism of tachycardia is required before ablation. Patients with concealed conduction over an AP have more frequently an association of AVRT and AVNRT than patients with a patent preexcitation syndrome. Rarely AVNRT can be the only mechanism of symptoms.

308 Are there indications for supraventricular re-entrant tachycardia in the youth?

Radiofrequency (RF) ablation of paroxysmal supraventricular tachycardia (SVT) that could be an atrioventricular node re-entrant tachycardia (AVNRT) or AV reentrant tachycardia (AVRT) through a concealed accessory pathway (AP) is widely used in adults, but the indications remain controversed in children and teenagers. The purpose of the study was to evaluate the clinical and electrophysiological factors of indications of AVNRT and AVRT ablation in the youth and the results of the procedure. Methods 66 children or teenagers aged from 6 to 18 years (15 ± 2) among 1099 patients consecutively recruited for SVT; they had a normal ECG in sinus rhythm; AVNRT or AVRT was confirmed at electrophysiological study (EPS). Patients with anterograde conduction through an AP were excluded. Results RF ablation was indicated in 26 children or teenagers (39%) (group I) significantly less frequently than in adults (668/1033; 65%) (p Conclusions The indications of slow pathway remain rare in children. Most of the indications of SVT ablation in the youth which are rare, concern generally the children and teenagers with concealed AP. The results are almost as good as in adults, mainly for the slow pathway ablation and in teenagers.

319 Is the rate in supraventricular tachycardia related to the age of the patient

The rate of supraventricular tachycardias (SVT) depends on the atrioventricular (AV) nodal conduction. Classicaly the maximal rate of AV nodal conduction decreases with the age. The purpose of the study was to look for the rate of induced SVT according to the age of the patient. Methods Electrophysiological study was performed in 1003 patients without WPW in sinus rhythm, but presenting with SVT; 68 were aged from 5 to 20 years (mean 15±3),102 from 21 to 30 (25±3), 134 from 31 to 40 (37±3), 188 from 41 to 50 (46±3), 187 from 51 to 60 (55±3), 155 from 61 to 70 (66±3), 155 aged from 71 to 80 (75±3), and 51 aged more than 80 years. SVT was induced by programmed atrial. Results The rate in SVT was similar in teenagers and adults until 50 years (mean 196±37 b/min) (respectively 197±29 b/min before 21 years, 217±44 b/min from 21 to 30 years, 193±40 b/min from 31 to 40 years and 192±33 b/min from 41 to 50 years) (NS). The rate in SVT was similar from 51 to 80 years (mean 172±33 b/min), but was significantly slower than before 51 years (p Conclusions The rate of SVT seems depend on the autonomic nervous tone. The rate was relatively high in teenagers but also in all adults

315 Indications of radiofrequency ablation of accessory pathway in the young population

Radiofrequency (RF) ablation of accessory pathway (AP) is widely used in Wolff-Parkinson-White syndrome (WPW), but the indications remain controversial in children and teenagers. The purpose of the study was to evaluate the clinical and electrophysiological factors associated with the indications of AP ablation in the youth. Methods 133 children and teenagers aged from 5 to 18 years (13.5±3) were admitted for a WPW and electrophysiological study (EPS) either for tachycardia, syncope or they were asymptomatic. EPS was performed in control state and after isoproterenol. Then RF ablation was proposed in case of recurrent tachycardias or induction of rapid atrial fibrillation (AF). Results AP ablation was indicated in 51 children (38%), several years after initial evaluation in 5 of them (group I), and was not performed in 82 children (group II). The indications did not differ significantly from the adult population (232/504, 46%). Clinical and electrophysiological data of groups I and II were compared. Group I was older than group II (15±2 vs 13±4) (p Conclusions The indications of AP ablation in the young population are based on recommended data and are similar to those of adults, with a similar risk of failure; they concern symptomatic or high risk children. The boys are referred more frequently than girls for the ablation.