The electrophysiologic properties in children at long term follow up after radiofrequency catheter ablation of the slow pathway due to atrioventricular nodal reentrant tachycardia

Abstract

The slow pathway radiofrequency ablation is effective method of treatment in children with atrioventricular nodal reentrant tachycardia. The aim of our study was to evaluate anterograde conduction properties in children after the slow pathway ablation, to determine the efficacy and safety of this method. Material and methods: Noninvasive transesophageal electrophysiological investigation was performed in 30 patients at the follow up period (mean duration 3.24 years) after the slow pathway radiofrequency ablation. Results: The slow pathway function was observed in 13 patients 1 day after ablation, in 26 patients at the follow up period, and in 28 patients after atropine sulfate. Atrioventricular node conduction decreased significantly (P<0.001) the following day after ablation to 165.2 (30.2) bmp and at the follow up to 146.3 (28.5) bpm versus the preablation 190.9 (31.4) bpm. The atrioventricular node effective refractory period prolonged significantly (P<0.001) the following day after ablation to 319.3 (55.3) msec and at the follow up to 351.0 (82.1) msec versus the preablation 248.3 (36.6) msec. Fast pathway effective refractory period prolonged significantly (P=0.005): 481.2 (132.9) msec in comparison with preablation 408.0 (60.4) msec. The prolongation of the slow pathway effective refractory period was more significant (P< 0.001) than the fast pathway effective refractory period at the follow up. Two late recurrences occured, one patient had atrial tachycardia. Conclusion: Anterograde conduction did not changed significantly after long term follow up. The end-point during slow pathway ablation should be the abolition of tachycardia with preservation of dual atrioventricular nodal physiology.