Long-term efficacy of radiofrequency catheter ablation in atrial tachycardia

Introduction and objectives. Radiofrequency ablation has shown to be an eff ective treatment for supraventricular tachycardias including flutter and at ria[ tachycardia, however the clinical information available on atrial tach ycardia is limited. The aim of this study was to evaluate the immediate and long term effectiveness of radiofrequency ablation in patients with atrial tachycardia and to establish predictors of effectiveness and arrhythmia re currence. Methods. We analyzed a series of 126 procedures of atrial tachycardia ablat ion in 117 patients (69% women) with a mean age of 50 +/- 19 years. Results. Ninety-one percent of the foci were located in the right atrium. A mean of 6 applications were necessary to achieve an efficacy of 74% during the first procedure with a total of 80%. The only predictor of ablation su ccess was the number of foci being smaller in multifocal compared to unifoc al (p < 0.01) whereas for recurrences a less premature electrogram at the a pplication point (p = 0.02) was predictive of ablation success. Over a foll ow-up of 34 +/- 19 months 7.4% of patients had recurrent atrial tachycardia . The probability of recurrence at one year calculated by the Kaplan-Meier method was 12%. Seventy-one percent of the recurrences occurred during the first 3 months after ablation. Conclusions. Ablation is an effective, safe procedure for short and long te rm treatment of patients with atrial tachycardia. Effectiveness depends on the number of foci while the recurrence rate is related to the prematurity of atrial electrogram at the application point.