Characterization, mapping, and catheter ablation of recurrent atrial tachycardias after stepwise ablation of long-lasting persistent atrial fibrillation

BACKGROUND: Atrial tachycardias (AT) often occur after ablation of long-lasting persistent AF (CAF) and are difficult to treat conservatively. This study evaluated mechanisms and success rates of conventional mapping and catheter ablation of recurrent ATs occurring late after stepwise ablation of CAF.

METHODS AND RESULTS: A total of 320 patients underwent de novo ablation of CAF using a stepwise ablation approach in 2006 to 2007 at our institution. This study comprised patients who presented with recurrent ATs at their first redo procedure after initial de novo CAF ablation. All procedures were guided by conventional mapping techniques exclusively. Sixty-one patients (63+/-10 years, 14 women) presented with their clinical AT at their redo procedure 7.7+/-4.4 months after initial de novo CAF ablation. A total of 133 ATs (2.2+/-0.9 per patient) were mapped. Forty-four (72%) were due to reentry; 17 (28%) were focal ATs. Reentry ATs were mainly characterized as roof and perimitral flutter (43% and 34%, respectively). Focal ATs mainly originated from the great thoracic veins (pulmonary veins: 41%, coronary sinus: 23%). Forty-five (74%) patients had conduction recovery of at least 1 pulmonary vein (mean, 1.2+/-0.8). Overall, 124 (93%) ATs could be ablated successfully. The mean procedure duration was 181+/-59 minutes, with a mean fluoroscopy time of 45+/-21 minutes. After a mean follow-up of 21+/-4 months, 50 (82%) patients were free of any arrhythmia recurrences after a single redo procedure.

CONCLUSIONS: Although late recurrent ATs may have complex mechanisms, catheter ablation guided exclusively by conventional techniques is highly effective with excellent acute and long-term success rates.