The radiofrequency catheter ablation of intranodal reentry tachycardia in children and adolescents]

INTRODUCTION: Radiofrequency catheter ablation of slow pathway is the primary nonpharmacological treatment for the atrioventricular node reentrant tachycardia at present. OBJECTIVES: To evaluate the results and long term follow-up of the catheter and radiofrequency modification of the AV node in the treatment of the atrioventricular node reentrant tachycardia in children and adolescents in our center. METHODS AND RESULTS: In a series of fifteen patients, 7 men and 8 women, with a mean age of 8.7 +/- 5.5 years (range, from 4 to 18) with atrioventricular node reentrant tachycardia underwent radiofrequency catheter ablation. Six patients had been treated previously with 1.4 +/- 1.1 antiarrhythmic drugs and nine had not received treatment. In all patients slow-pathway atrioventricular node ablation guided by an anatomic stepwise approach was attempted. In 14 out of 15 patients slow pathway was successfully ablated; and in one patient with a previously failed slow-pathway ablation, a fast-pathway ablation was performed. Tachycardia recurred in one patient, and slow pathway was ablated in a second procedure. After successful slow pathway ablation in 14 patients, the shortest cycle length in which the AV conduction was maintained at 1:1, was increased from 271.3 +/- 22.6 to 316.7 +/- 30.1 ms (p < 0.001), while the AH and HV intervals and shortest cycle length of 1:1 VA conduction remained unchanged. In the patient who had fast pathway ablation the AH interval was increased from 65 to 130 ms, and retrograde VA conduction was lost. Noninducibility of the tachycardia was achieved in all patients without significant complications. During a mean follow-up of 18.8 +/- 11.4 months (median of 16), all patients are symptom-free without medication. CONCLUSIONS: Radiofrequency catheter ablation is a successful and safe therapeutic alternative in the treatment of atrioventricular node reentrant tachycardia in children and adolescents.