Common atrial flutter and atrial fibrillation are not always two stages of the same disease. A long-term follow-up study in patients with atrial flutter treated with cavo-tricuspid isthmus ablation.

Objective: Both atrial flutter and atrial fibrillation (AF) frequently develop in the same patient. There is therefore reasonable doubt that flutter ablation may not solve the clinical problem, owing to the occurrence/recurrence of AF. The aim of this study was to establish whether cavo-tricuspid isthmus ablation is curative in patients with common atrial flutter alone or combined with AF.

Methods: One hundred and forty-one patients (114 male, 27 female, mean age 63 +/- 10 years) who had cavo-tricuspid isthmus ablation were followed up for 44 +/- 20 months. Before ablation, 48 patients had only atrial flutter (group A), whereas 93 patients had both atrial flutter and AF. Among the latter, during antiarrhythmic therapy, 31 patients had only atrial flutter (group B1), whereas 62 patients (group B2) continued to experience both arrhythmias.

Results: During follow-up, 27% of group A and 61% of group B patients had documented recurrent AF (P < 0.001). AF recurred in 51% of group B1 and in 66% of group B2 patients (P = NS). Permanent AF occurred in 6% of group A, 3% of group B1 and 21% of group B2 (P < 0.01). Specific symptom scale scores significantly decreased in all groups, particularly in group A. Two patients of group B had cerebral ischaemic attacks.

Conclusions: Over a long-term follow-up, cavo-tricuspid isthmus ablation is curative in >70% of patients with atrial flutter alone. Therefore, if no AF is documented, more extensive ablation is not needed. By contrast, cavo-tricuspid isthmus ablation is frequently unable to prevent AF in patients with both atrial flutter and AF, although in some cases a significant clinical benefit may be obtained.